39Th Annual Conference of the European Prosthodontic Association September 3–5, 2015 Prague, Czech Republic

39th Annual Conference of the European Prosthodontic Association September 3–5, 2015 Prague, Czech Republic

www.epa2015.cz www.epadental.org

1OB.indd 1 19.8.2015 19:48:55 Philips Sonicare invites you to an interactive workshop Modern Hygienic Methods and Dental Implants

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2OB.indd 1 20.8.2015 17:35:55 39th Annual Conference of the European Prosthodontic Association

39th Annual Conference of the European Prosthodontic Association

Conference is held under the auspices of the Rector of Charles University in Prague

Organizer: Czech Society of Prosthetic Dentistry in the cooperation with Czech Dental Chamber

September 3–5, 2015 Prague, Czech Republic

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CONTENTS

1. PRESIDENT’S MESSAGE 3 2. CONFERENCE INFORMATION 4 3. GENERAL INFORMATION 5 4. SOCIAL PROGRAMME 6 5. SCIENTIFIC PROGRAMME 8 6. KEYNOTE LECTURES 14 7. WORKSHOP LECTURES 27 8. ORAL PRESENTATIONS 28 9. POSTER PRESENTATIONS 59 10. LIST OF THE MAIN AND PRESENTING AUTHORS 147 11. EPA 39th ANNUAL CONFERENCE PARTNERS 150

This conference is credited with 11 points by the Czech Dental Chamber.

www.epa2015.cz www.epadental.org

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1. PRESIDENT’S MESSAGE

Dear colleagues, let me invite you warmly in Prague to gain the latest news and experience with implants hand in hand with conventional prosthodontics. After fourteen years the 39th Annual Conference of the European Prosthodontics Association (EPA 2015) returns to Prague, the heart of Europe. This congress will be organized in the centre of Prague from September 3 to 5, 2015.On behalf of the Organizing Committee I would like to introduce the main theme of the meeting: Implants Hand in Hand with Conventional Prosthodontics. Dear colleagues, we are sure, that mentioned theme would inspire you to your active presentation and to discuss your experience with EPA specialists and other experts from all over the world.

Topics of the meeting fluently follow on the last EPA Conference in Istanbul, 2014, and are focused on: • Implants and conventional prosthodontics – friends or enemies? • Interdisciplinary cooperation, perio-compromised patients. • Prosthodontics for young patients. • Prosthodontics for elderly. • New trends in materials and technologies. • Teaching prosthodontics – difficult or easy? • Valuable case reports. The Scientific Committee drew the inspiration for the programme from a technology revolution and its impact on the everyday dental practice. There are questions: How long can we assume the coexistence of conventional and computerised methods in prosthetic dentistry? What is the philosophy of current conception of prosthetic treatment? What and how to teach in graduate and postgraduate training? How can science and research enhance the progress in prosthetic dentistry? We are sure that our meeting would help to answer not only these questions. The organizers are proud of possibility to welcome in Prague well known specialists from all dental branches, experienced dental practitioners and students for unique discussion. We invite you warmly to active presentation at oral and poster sessions, and also workshops focusing on microscopic approach in dentistry, modern hygienic methods with dental implants and fibre reinforced composites in implant reconstructions. There are opportunities for young colleagues to take part in a competition for valuable prizes which are sponsored by supporting partners – Philips, Intensiv, Everydent, Dentsply, ADM, Kerr, Den- tamed, Osstem Implant, Dentis, 3M ESPE, JPS. The Czech Society of Prosthetic Dentistry hand in hand with the Czech Dental Chamber hopes that common effort during the Congress organization will create a nice atmosphere for this meeting.

Prof. Dr. Hana Hubálková Congress President EPA President 2014–2015 Chairperson of Organizing Committee

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Organizing Committee

Assoc. Prof. MUDr. Hana Hubálková, Ph.D., Congress President Prof. Dr. Mutlu Özcan, Ph.D. Assoc. Prof. MUDr. Marie Bartoňová, CSc. MUDr. Lenka Vavřičková, Ph.D. MUDr. Jindřich Charvát, CSc. MUDr. Richard Klail

2. CONFERENCE INFORMATION Registration/Information Desk The registration/information desk will be ready to assist you at the Conference Venue during the meeting. On-site registration is possible at the registration desk. If you need any other information about city tours, shopping and transportation, please do not hesitate to ask the staff of registration/information desk. The desk will be open during the following hours: Wednesday September 2, 2015 14:00 – 17:00 Thursday September 3, 2015 8:00 – 17:00 Friday September 4, 2015 8:00 – 17:00 Saturday September 5, 2015 8.00 – 14:00

Language The official language of the Conference is English, including all oral and poster presentations.

Keynote Lectures Oxford Lecturer and the Invited Keynote Speakers will deliver their presentations throughout the whole congress program.

Oral Presentations – Parallel Sessions Oral Presentations No. O-1 – O-60 will be held in Conference Hall II and Hall III. 10 minutes will be allowed for each oral presentation. Discussion will follow the block of lectures at the end of the session. Technical staff in the Hall II and Hall III will be ready to take over your presentation: Thursday September 3, 2015 15:15 Hall III Friday September 4, 2015 10:30 Hall III Friday September 4, 2015 13:00 Hall II, Hall III Saturday September 5, 2015 8:30 Hall II, Hall III

Poster Presentations Posters will be presented at the congress hotel groundfloor. A unique number is assigned to every poster presentation and it serves for the localization of the poster board in the poster presentation area. Numbers are available in the Abstract Book. Author must be present next to the poster for the explanation and the discussion: Thursday September 3, 2015 15:15 – 15:45 Friday September 4, 2015 10:30 – 11:00 Poster presentations have been assigned into two sessions. Group 1 on Thursday and Group 2 on Friday. Poster presentations will be set up daily.

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Group 1 Thursday, September 3, 2015 Poster Presentation No. P-1 – P-86 8:30 – 9:00 poster set-up 17:00 – 17:30 poster tear-down Group 2 Friday, September 4, 2015 Poster Presentation No. P-87 – P-176 8:00 – 8:30 poster set-up 17:30 – 18:00 poster tear-down

Workshops There will be 3 hands-on courses. Only 20 applicants will be accepted for each workshop. More information available at the registration desk.

Abstracts All abstracts for oral and poster presentations have been peer-reviewed. All accepted abstracts are published booth in the Abstract Book and in the electronic form (www.epa2015.cz).

Awards EPA 2015 Award Committee promotes EPA Oral and Poster presentation prize for the best oral and poster presentations. More information on awards is available on www.epadental.org.

Trade Exhibition Throughout the whole conference there will be a trade exhibition in congress halls vestibule.

3. GENERAL INFORMATION

Conference Venue Designhotel Elephant, Prague Conference Centre U Hajku Address : Na Florenci 29, 110 00 Praha 1, Czech Republic Phone : +420 227 279 111 Fax: +420 211 159 159 Web: [email protected] www.hotel-elephant.cz Conference Centre U HAJKU is connected with Designhotel Elephant and Grandior Garage park- ing on the premises for a fee.

Registered congress participants are entitled to participate in the scientific sessions, morning and afternoon tea and coffee breaks, lunch and attend Welcome Reception. Specially purchased entrance tickets are required for the Gala Dinner.

Registered accompanying persons are only entitled to attend Welcome Reception.

Badges All participants will receive a personal Congress Badge at the Registration desk. Please wear your Congress Badge at all times for admission to all scientific sessions and all other events during the Congress.

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Insurance Please note that the congress participants are not covered by any insurance (travel, medical, accident or liability) taken by the Congress Organizers. The Congress Organizers cannot accept liability for any loss or damage suffered by any participant or accompanying person or other person during travel to and from the conference or during the conference, official activities and the excursions. Participants are advised to consider purchasing their own travel insurance and to extend their personal policy to cover personal possessions.

Conference and Administration Office – contact In matters related to registration, payment and accommodation, please contact: Congress centre of the Czech Dental Chamber Slavojova 22 128 00 Praha 2 Czech Republic Mrs. Hana Štěpánková [email protected] phone: +420 234 709 613 fax: +420 234 709 619

4. SOCIAL PROGRAMME

Welcome Reception – Great Hall of the Carolinum – Historical Campus of Charles University Address: Ovocný trh 3, Praha 1 (Carolinum is in walking distance from the congress venue) Thursday, September 3, 2015 from 19:00 19:00 welcome 19:15 guided tour – historical rooms Welcome Cocktail will be served at the historical ground floor. Accompanying person 40 EUR, the event is free of charge for registered participants, but prereg- istration is required.

Gala Dinner Address: Obecní dům, náměstí Republiky 5, Praha 1 Gala Dinner will be served on Friday, September 4, 2015 from 19:30 Municipal House, an Art Nouveau architecture building near the congress centre Web: www.obecnidum.cz The price is 120 EUR per person. We would kindly remind you that early reservation is required and attendance will be limited. Please bring your Gala Dinner cards.

Programme for accompanying persons All tours include lunch, entrance fees and transportation.

Kutná Hora tour Thursday, September 3, 2015 Price 56 EUR per person Kutná Hora is a small town situated 70 km east from Prague. It was a rich and important medieval mining and minting place. After silver ore resources had been exhausted, it became a provincional town and its historical heart remained almost untouched. Unfinished, but impressive with it’s natural surroundings remains St. Barbara’s Cathedral. Unusually bright interior of The Assumption of the Virgin Mary Cathedral renewed by baroque ar-

6 39th Annual Conference of the European Prosthodontic Association chitect Jan Blažej Santini Aichl, well known Ossuary and many other monuments including small open part of medieval mine are also worth seeing. The tour includes visit of St. Barbara`s Cathedral where a short organ concert will be held. After walk through the historical heart and lunch, Assumption of the Virgin Mary Cathedral and Ossuary in nearby Sedlec will be visited.

Karlštejn tour Friday, September 4, 2015 Price 52 EUR per person Karlštejn is a medieval castle near Prague founded by Emperor Charles IV as an intended treasury for Imperial Regalia. In the Holy Cross Chapel were protected by the holy army consisting of about 130 saint patrons present in panel paintings serving at the same time as reliquaries.

Prague walking tour Saturday, September 5, 2015 Price 40 EUR per person Prague Castle is one of the largest castles in the world. Its rich historical fundament and surrounding gardens were coronated by timeless adaptation by Slovenian architect Josip Plecnik in twenties and thirties of 20th century. The walk begins in the area of the castle, goes through picturesque Malá Strana quarter (Lesser Town), crosses the Vltava river over Charles Bridge and finishes at the Old Town.

Tours run with min. 20 participants. In case of cancellation, you will be notified by e-mail. Theatre performance lack theatre, opera, ballet according to actual offer.

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5. SCIENTIFIC PROGRAMME

Thursday, September 3, 2015 General Sessions General Session I Hall I 13:00–13:15 Opening Ceremony 13:15–14:15 Prospects of prosthodontics in the era of oral implants Cees de Baat, The Netherlands 14:15–15:15 Is evidence based treatment planning in prosthetic dentistry realistic or only an illusion? Bjarni E. Pjetursson, Iceland

General Session II Prosthodontics for young patients Hall I 15:45–16:30 Dental implants in orthognatic surgery patients René Foltán, Czech Republic 16:30–17:15 Clinical management of multiple genesis – demanding procedure to goal Ivo Marek, Czech Republic

General Session III Prosthodontics for elderly Hall II 15:45–16:30 Telescopic dentures in elderly patients and severely reduced dentitions Jürgen Setz, Germany 16:30–17:15 Oral health, masticatory efficiency and prosthetic treatment in older patients Angus Walls, United Kingdom

General Session IV Prosthodontics for young patients Hall III 15:45–16:10 Implant treatment in young patients Pavel Kříž, Czech Republic

Friday, September 4, 2015 General Sessions Oxford lecture Hall I 9:00–10:30 Implants and conventional prosthodontics: Friends or enemies? Thomas J. Salinas, USA

General Session V Implants and conventional prosthodontics: Friends or enemies? Hall I 11:00–12:00 Implants in frontal area – challenge for long-term survival and maximal esthetics Jiří Krug, Czech Republic 12:00–12:30 Implants and implant retained restorations: Friends or enemies Nicola West, United Kingdom 12:30–13:00 Implant maintenance and soft tissue management: Critical factors for long-term success Juliette Reeves, Switzerland

General Session VI Teaching prosthodontics – difficult or easy Hall II 11:00–12:00 Challenges in teaching of prosthodontics Timo Närhi, Finland 12:00–12:30 The undergraduate and postgraduate studies in the university clinic of dentistry of Vienna Anna Knaus, Austria 12:30–13:00 Classical and computerized modern implant-prosthetic rehabilitation Norina Forna, Romania

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General Session VII Teaching prosthodontics – difficult or easy Hall III 11:00–11:20 Implant prosthodontics: Undergraduate or postgraduate discipline? George Papavasiliou, Greece

General Session VIII Interdisciplinary cooperation for perio compromised patients Hall I 14:30–15:30 The prosthodontic dilemma in restoring the periodontally – compromised patient Alberto Fonzar, Italy 16:00–16:45 Digital reconstruction and interdisciplinary cooperation in surgical design and simulation Suresh Nayar, Canada 16:45–17:30 Agressive periodontitis and orthodontic treatment Ivo Dřízhal, Czech Republic

General Session IX Interdisciplinary cooperation for perio compromised patients Hall II 14:30–14:50 Complete reconstruction of the dentition using dental implants Antonín Šimůnek, Czech Republic

General Session X Interdisciplinary cooperation for perio compromised patiens Hall III 14:30–14:50 Intrusion of supraoccluded molars with temporary anchorage devices before a prosthetic reconstruction Josef Kučera, Czech Republic

Saturday, September 5, 2015 General Sessions General Session XI New trends in materials and technologies Hall I 09:00–10:00 Digital technology – new materials, new possibilities, unlimited indications? Irena Sailer, Switzerland, USA 10:00–10:45 Integration of new materials and concepts in interdisciplinary implant procedures Albert Waning, The Netherlands 11:15–12:00 Just screw it? Screw – retained versus cemented reconstructions Petr Barták, Czech Republic 12:00–13:00 Czech archaeological explorations in Egypt and Sudan Miroslav Verner, Czech Republic

General Session XII New trends in materials and technologies Hall II 09:00–09:20 Robotic prosthodontics Roman Šmucler, Czech Republic

General Session XIII New trends in materials and technologies Hall III 09:00–09:20 New horizons in implant prosthodontics: CAD/CAM-individual implant abutments Peter Gehrke, Germany

13:00 Closing Ceremony

Parallel Sessions

Thursday, September 3, 2015, Hall III

16:10 O-1 Comparison of cytokine production by SaOS-2 and immunocompetent cells cultivated on alginate surfaces doped with calcium phosphates Lucie Himmlová, Czech Republic 16:20 O-2 Evaluating denture hygiene in head and neck oncology patients Petros Mylonas, UK 9 39th Annual Conference of the European Prosthodontic Association

16:30 O-3 Temporomandibular joint disorders from perspective of craniometric and myographic parameters Maksim Yurchenko, Czech Republic 16:40 O-4 Short dental implants success in edentulous posterior maxilla Igor Linetskiy, Czech Republic 16:50 O-5 The virtual prosthodontic patient: Integrating facial, intraoral and CBCT datasets Bassam Hassan, The Netherlands 17:00 O-6 Retrospective study of extensive ceramic veneers – 7 year results Sven Rinke, Germany 17:10 Discussion

Friday, September 4, 2015, Hall III

11:20 O-7 Effect of thermal and mechanical cycling on dentin bond strength Haluk Baris Kara, Turkey 11:30 O-8 Micro-shear bond strength according to dentin cleansing methods before recementation Simge Taşar, Turkish Republic of Northern Cyprus 11:40 O-9 Evaluation of shear bond strength of two resin cements on different CAD/CAM materials Ozlem Ustun, Turkey 11:50 O-10 Bond streght of composite resins to CAD/CAM fiber-reinforced composite blocks Pinar Adimci, Turkey 12:00 Discussion 12:10 O-11 Effect of cement film thickness on the strength of all-ceramic crowns Abdurrahman Şahinbaş, Turkey 12:20 O-12 Effect of selective infiltration etching for resin cementation of zirconia Merve Çakirbay Taniş, Turkey 12:30 O-13 Effect of femtosecond laser angles and shapes to zirconia-resin bond strength Yener Okutan, Turkey 12:40 O-14 Contemporary view on dental materials and MRI Hana Hubálková, Czech Republic 12:50 Discussion

Friday, September 4, 2015, Hall II

14:50 O-15 Effectiveness of a universal adhesive on bond strength to dentin M. Erhan Comlekoglu, Turkey 15:00 O-16 Fracture surface analysis of PM CP titanium after ceramic debonding Josko Viskic, Croatia 15:10 O-17 Adhesion between composite and titanium with different metal primers Ayşe Yalnız, Turkey Presentation was cancelled. 15:20 Discussion 16:00 O-18 Corrosion behaviour of dental ceramics Lenka Vavřičková, Czech Republic 16:10 O-19 The era of monolithic translucent zirconia: Two case reports Despoina Chatzistavrianou, UK 16:20 O-20 Effect of surface treatments on bond strength of CAD-on technique Tuba Yilmaz, Turkey 16:30 O-21 Shading impact on the bond of Y-TZP to resin cement Farhad Tabatabaian, Iran 16:40 Discussion 10 39th Annual Conference of the European Prosthodontic Association

16:45 O-22 Topographical properties of zirconium-dioxide: Effect of polishers with different surface-coatings Mutlu Özcan, Switzerland 16:55 O-23 Professional smile designing: Going digital Mohannad Kiswani, Jordan 17:05 O-24 Factors influencing the dimensional accuracy of 3D-printed full coverage dental restorations using stereolithography technology Nawal Alharbi, The Netherlands 16:15 O-25 Some anatomical considerations for implant-supported restorations in edentulous patients Yoav Pietrokovski, Israel 16:25 O-26 Multidisciplinary intervention for prosthetic rehabilitation Arman Barfeie, UK Presentation was cancelled. 16:35 Discussion

Friday, September 4, 2015, Hall III

14:50 O-27 Alternative attachment incorporation methods in implant-supported overdentures with non-splinted abutments Cumhur Sipahi, Turkey 15:00 O-28 Evaluation of immeditate loaded implants in single tooth missing zone Yıldız Pınar, Turkey 15:10 O-29 Fracture resistance of oval and circular dowels used in oval root canals Halil İbrahim Kılınç, Turkey 15:20 Discussion 16:00 O-30 Stress distribution in cantilevered fixed partial denture with different C/I ratio Hamiyet Güngör, Turkey 16:10 O-31 Prevalence and risk variables analysis for peri-implant disease K. C. (Basnyat) Smriti, Nepal 16:20 O-32 Replacing first premolar and first molar with cantilever bridge: A clinical study S. M. R. Sazvar, Iran 16:30 O-33 Influence of different protocols for cement removal during cementation on implants Larisa Jercan, Romania 16:40 Discussion 16:45 O-34 Pain and dysfunction after changing the VDO – digital analysis and occlusal hygiene Hans van Pelt, The Netherlands 16:55 O-35 Interdisciplinary creation of bone and teeth after severe trauma Rob Groot, The Netherlands 17:05 O-36 Laser application in modern dental medicine Doriana Agop-Forna, Romania 16:15 O-37 Implant treatment in a patient who is under methotrexate medication: A case report Polykarpos Papanagiotou, Greece 16:25 O-38 Bruxism and tinnitus Radmila Sedláčková, Czech Republic 16:35 Discussion

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Saturday, September 5, 2015, Hall II

09:20 O-39 Cleft patients – solutions of dental defects Wanda Urbanová, Czech Republic 09:30 O-40 No time limit for using autotransplants Dick Barendregt, The Netherlands 09:40 O-41 Autotransplantation in young patients after dental trauma in anterior teeth in the upper jaw: Review of a guideline Pieke Wagemakers, The Netherlands 09:50 O-42 The gradation of the color in natural teeth Teuta Pustina-Krasniqi, Republic of Kosovo 10:00 Discussion 10:10 O-43 Restorative aspects after autotransplantation in young patients with traumatized dentitions Marcel Linssen, The Netherlands 10:20 O-44 Is there consensus among specialized dentists and oral surgeons for autotransplantation after loss of anterior teeth in the upper jaw in young patients? Marliek Ravenshorst, The Netherlands 10:30 O-45 Prosthetic rehabilitation of growing patients with ectodermic dysplasia Ioli Ioanna Artopoulou, Greece 10:40 Discussion 11:15 O-46 The effect of a key-way preparation on fracture resistance of teeth restored with different post systems Eda Ozdere, Turkey 11:25 O-47 Immediate loading screwed crowns on 3.0 implants: A 3-year follow-up Rafael Martinez-de Fuentes, Spain 11:35 O-48 Veneer firing effects on zirconia Hasan Murat Aydogdu, Turkey 11:45 O-49 Accuracy of vinyl-polysiloxane and polyeter one-step impressions in-vivo Aslıhan Köroğlu Kale, Turkey 11:55 Discussion

Saturday, September 5, 2015, Hall III

09:20 O-50 Color measurement of composites: Is the VITA Shade Guide the reference? Alexander Schryvers, Belgium 09:30 O-51 Survival rate of indirect lithium disilicate restorations after 5, 10 and 17 years Carolien Vinkenborg, The Netherlands 09:40 O-52 Current trends in teaching tooth colour selection and communication in prosthodontics Aspasia Sarafianou, Greece 09:50 O-53 Effect of method, expertise and inter-examiner variability in evaluating crown preparations Syed Rashid Habib, Saudi Arabia 10:00 Discussion 10:10 O-54 Histo-morphological study of functional overload (clinical-experimental study) Alketa Qafmolla, Albania 10:20 O-55 Impact of removable partial dentures on masticatory efficiency and comparison with natural dentition Linda Dula, Republic of Kosovo 10:30 O-56 The reasons for acceptation or refusing the recommended prosthetic treatments Sherif Shaqiri, Macedonia 10:40 Discussion 12 39th Annual Conference of the European Prosthodontic Association

11:15 O-57 Patient’s satisfaction with removable partial dentures Blerim Kamberi, Republic of Kosovo 11:25 O-58 Effect of denture cleansers on matrice retention of precision attachments Umut Cakan, Turkey 11:35 O-59 Comparison of two techniques to achieve postdam for maxillary dentures Hanum Kassim Zethy, Malaysia Presentation was cancelled. 11:45 O-60 The effect of removable partial dentures on the periodontal health of abutment and non-abutment teeth Kujtim Shala, Republic of Kosovo 11:55 Discussion

Workshop programme

Thursday, September 3, 2015

Workshop I 8:30–12:00 Fibre reinforced composites in treatment with dental implants Dr. Otakar Dubec, Czech Republic Partner: ADM, a.s.

Workshop II 8:30–12:00 Microscopic dentistry in fixed prosthodontics Dr. Daniel Ott, Czech Republic Partners: KaVo Kerr Group, EveryDent, s.r.o.

Workshop III 8:30–12:00 Modern hygienic methods and dental implants Mrs. Kateřina Ciklová, Mrs. Jana Křepelková, Czech Republic Golden Partner: Philips Česká republika, s.r.o.

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6. KEYNOTE LECTURES

Keynote Lecture No. 1 Oxford Lecture Implants and conventional prosthodontics: Friends or enemies? Thomas J. Salinas, USA

Dental implants are often used as part of prosthodontic treatment for patients with simple and complex needs. For decades, implants have been used as alternatives to conventional prosthodontic treatment and also in conjunction with this treatment. Fundamental anatomic and physiologic differences exist where implants are thought to be augmentive or sub- stantive support giving rise to pursuing outcome-based evidence for their use in prosthodontic intervention. Extended use of dental implants in fixed, removable and maxillofacial prosthodontics have more reported outcomes and will continue to become important in ranking quality of life improvement. Further use of implants in developing patients, the elderly and periodontally compromised patients serve these populations well. Care must be taken to insure that structured treatment accompanies case specific circumstances. The development of materials in dentistry has taken on a renaissance in the last decade, where computer aided designed alloys and ceramics have predominated. Although material consideration is important for understanding construction requirements, thorough diagnosis and design principles will also take some consideration. Patients requiring full or partial arch prosthesis replacement of a dentition can be treated in a variety of pathways. The primary diagnostic sequences should give a general vision of patient expectations, available anatomy, interarch distances, and biomechanical design. The synergistic use of three dimensional imaging and virtual software planning has helped achieve advanced concepts in treatment that will continue to be surveyed for favorable patient outcomes.

Keynote Lecture No. 2 Prospects of prosthodontics in the era of oral implants Cees de Baat, The Netherlands

Nowadays, in many cases, oral implants are the first choice for people who have lost a tooth or teeth due to an injury, carious lesions, periodontal disease or some other reason. Ideal candidates for a treatment with oral implants are people in good general health and acceptable oral health, consisting of healthy periodontal tissues and locally at edentulous sites an adequate amount of healthy bone to support an implant or implants. These requirements are not very often present in frail or dependent older people. In addition, the daily oral self care of frail older people as well as the daily professional oral health care to dependent older people may be unsatisfactory. Consequently, oral implants are not indicated in many older people cases. In those cases, conventional prosthetic treatments are the treatments of choice and may yield acceptable results. However, indicating and carrying out these treatments require some experience and insight into the physical, social and cognitive problems and living environments of frail and dependent older people. During the lecture, the entire area of tension for oral healthcare providers treating frail and dependent older people will be illustrated by showing actual practical non-implant case reports.

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Keynote Lecture No. 3 Is evidence based treatment planning in prosthetic dentistry realistic or only an illusion? Bjarni E. Pjetursson, Iceland

In daily practice, dentists routinely face the challenge of making fast and difficult decisions. These are mostly influenced by paradigms dictated by basic dental education and many years of clinical practice. Scientific evidence provided by well-controlled studies is rarely available to influence and/or determine the treatment plan. When planning a fixed reconstruction, the options are tooth-supported or implant-supported fixed dental prostheses (FDPs) or single crowns (SCs). These treatment options have various documented longevities and biological as well as technical risks that should be considered during treatment planning. As there are no randomized controlled clinical trials (RCTs) in the dental prosthetic literature comparing tooth-supported FDPs to implant-supported FDPs, it is an open question whether or not the practice of evidence-based treatment planning is at all possible in prosthetic dentistry. Ideally, treatment decisions should be based on well-performed systematic reviews of the available evidence and, if possible, on formal quantitative evidence synthesis and meta-analysis. If there are no studies on the highest level of evidence, the systematic review has to be based on the highest level of evidence available.

Keynote Lecture No. 4 Dental implants in orthognatic surgery patients René Foltán, Czech Republic

Dental implants are standard of care in dentistry and probably the best option for missing tooth replacement. Today the orthognatic surgery is going to be an integral part of standard orthodontics care too. Indications are not only to improve occlusion, but facial esthetics and upper airways patterns too. For these reasons many patients underwent orthognatic procedure in older age, when they have a few teeth missing, and therefore prosthodontists and implantologist should be members of multidisciplinary team in this cases. It is necessary, that standard implants treatment protocols have to be modified because of combine orthodontic-surgical treatment. Timing and amount of tooth movement in decompensation period, types of orthognatic procedures, planning new occlusion and facial esthetics must be considered not only before implant placement planning but alveolar bone reconstruction too. Since there is no official protocol we will show in our case series basic principles of care to follow and common mistakes to avoid.

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Keynote Lecture No. 5 Telescopic dentures in elderly patients and severely reduced dentitions Jürgen Setz, Germany

In the severely reduced dentition (less than 4 teeth) dentists face the question whether to extract the remaining teeth or to use them for support and retention of a denture. If the teeth are kept an attachment is needed to fix a denture to the teeth. Telescopic crowns (parallel milled primary crowns with precisely fitting secondary crowns) are one the options for an attachment. Although telescopic crowns are well established and well clinically investigated there is little information available about their use and benefit in elderly patients and severely reduced dentitions. From 2002 to 2004 we started a prospective clinical study. 173 telescopic crowns with 82 dentures were inserted in 74 patients. There was a follow up every 6 months until 2014. The dentures showed very high patient satisfaction. The survival rate (Kaplan/Meier) for a telescopic crown in 10 years was 65%. Survival of the telescopic crowns depended on number and distribution of teeth. About 80% of the dentures still have at least one telescope for retention and support. About 20% of the dentures lost all teeth and were transferred into a complete denture. The lecture discusses clinical parameters that influenced the survival, complications and dental procedures which became necessary during the follow up. Finally new digital technologies are presented, which make the production of telescopic dentures easier.

Keynote Lecture No. 6 Implant treatment in young patients Pavel Kříž, Czech Republic

Nowadays is ever increasing number of patients treated with dental implants before 18 years of age. There are several reasons. These include loss as a result of tooth decay, trauma of the tooth with its subsequent loss. Another important group is adolescents with agenesis of permanent tooth/teeth. Treatment using the dental implants is always possible after the completion of skeletal growth, which must be verified. These groups of patients often require complex treatment, including orthodontic pretreat- ment. It is necessary to create enough space for the implant placement, and then to start its prosthetic reconstruction. Lack of bone is solved according to the amount of bone loss using bone augmentation. In favorable cases is preferred immediate implant insertion and immediate reconstruction after extraction of deciduous tooth. For esthetic outcome and stability is efficient augmentation of soft tissue. For optimal results, the therapy requires the cooperation of the entire dental team. Using dental implant we can fully reconstruct the dental arch in very young patients.

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Keynote Lecture No. 7 Clinical managment of multiple agenesis – demanding procedure to the goal Ivo Marek, Adam Vilášek, Martin Starosta, Czech Republic

Agenesis of teeth and specially multiple agenesis is a rare kind of anomaly and its solution could be rather difficult – including setting up an ideal treatment plan and co-ordinating the whole treatment process – since several dental disciplines take part in the process of the treatment. When setting up the treatment plan, not only the number of teeth of agenesis, but also the sagital relation of jaws and vertical discrepancy have to be taken into account. Therefore, orthodontic therapy often consists of only adjusting the position of pillars and gaps in the place of agenesis, then the prosthetic reconstruction takes place. The age of the patient together with the plan of implant insertion are other important factors when planning the final prosthetic reconstruction. The authors analyse the process of treatment plan formation on several cases of young patients, then possible complications, which can occur during the treatment, together with consequetial modifications. Also criteria for treatment protocol of agenesis lateral incisors and lower incisors and premolars will be discussed. Resolving multiple agenesis is thus based on interdisciplinary co-operation of an orthodontist, prosthodontist and implantologist; in some cases a maxillofacial surgeon can be involved. The authors stress the importance of the therapy coordinator who manages individual phases of the treatment, who bears the responsibility for forming the team, as well as for the treatment results.

Keynote Lecture No. 8 Oral health, masticatory efficiency and prosthetic treatment in older patients Angus Walls, United Kingdom

The population of developed nations is ageing the world over resulting in many more older people needing oral health care. Historically many were edentulous but we are now faced with more dentate older people but with limited dentitions. There is an increasing awareness of the relationship between oral function and foods choice which may have a direct impact on diet leading to self-imposed dietary restriction in older people. At the same time energy requirements reduce and micro-nutrient requirements remain constant in older populations, changes that are diametrically op- posed to the normal pattern of dietary change seen with reduced masticatory functional this presentation will explore the interactions between oral health and nutrition in older people and strategies that should be used to help our older patients maintain the diet they require into old age.

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Keynote Lecture No. 9 Implants in frontal area – challenge for long-term survival and maximal esthetics Jiří Krug, Alena Krugová, Czech Republic

Implant placement in the upper frontal area is usually combined with insufficient bone reconstruction and soft tissue augmentation. The prosthodontic reconstruction consists of set of complexed steps from provisional to permanent crown delivery. Eighty patients (2008–2012) who received single tooth implants with bone regeneration in the anterior maxilla were enrolled in the study (32 central incisors, 49 lateral incisors, and 11 canines). All implants were healed submerged and provisional screwed crowns were fabricated. Eighty-six implants were bone level implants (Straumann® Bone Level) and six implants were tissue level (Straumann® Standard Plus). Only all-ceramic crowns either cemented on abutments or screwed directly into implants were used. In the first part of the study, group of patients with bone level implants, at least two years after permanent crown delivery, were clinically examined and radiologicaly recorded including esthetic parameters (PES & WES). In the second part of the study, a group of 24 patients (30 implants) loaded with hybrid yttrium stabilized zirconia abutments and adhesively cemented all-ceramic crowns were evaluated. Modified United States Public Health Service criterias were used to assess technical outcomes. In group of eighty patients, one implant failed during the healing period. In two implants, periimplantitis occurred and both conservatively and surgically were well managed. Other 89 implants were stable without any biological complications. The average PES and WES values were above 7.5 and 7.7 respectively. In the group of 24 patients, no abutment or crown was fractured; no abutment or screw loosening or chipping was found.

Keynote Lecture No. 10 Challenges in teaching of prosthodontics Timo Närhi, Finland

Changes in demographics and oral health have altered patients’ demands for the prosthetic treatments. Edentulousness is decreasing and people tend to retain their natural dentition into late life. However, condition of the dentitions does not guarantee functional occlusion without prosthetic interventions. Dental treatment need is polarizing into the old age groups and new generations have increasing demands towards dental treatments including prosthetic rehabilitations. This can be seen in the increasing request of fixed restorations. On the other hand, many partial dentate persons get their first removable prosthesis later in their life. Material and technical development has been very fast in recent years. This is mainly due to fast progress the of CAD/CAM techniques. Today dentists have many alternative methods for replacing missing teeth and vast choice of materials to choose from. Aging patient population can also complicate treatment planning. Dental educators have to adapt their curriculum according to the changing world. New generation of dentists will require completely new kinds of skills and more knowledge on general medicine. However, these challenges are very difficult to meet without leaving out some traditional contents of prosthodontic education. This lecture will highlight the future demands for prosthetic curriculums. It will also discuss about the importance of traditional prosthetic courses under the pressure to adapt teaching programs with the increasing demands. One of the goals is to stimulate the educators to seek more effective teaching methods that can assure effective learning in modern environment.

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Keynote Lecture No. 11 Implant prosthodontics: Undergraduate or postgraduate discipline? George Papavasiliou, Greece

Osseointegrated implants have changed the way we think about oral rehabilitation over the last thirty years. Their evolution from a questionable remedy to a trustworthy clinical application passed through a series of stages, some of them confusing but most of them rewarding. There were technical problems to be solved like choosing among external and internal connection, the size and material of the holding screw or the amount of preload necessary. There were biological processes to be understood like which types of surfaces the osteoplasts really like, how long does an implant need before it can bear load or which types of grafting materials work. There were also surgical techniques and prosthetic approaches to be improved in order to be able to get a safer more esthetic and long lasting outcome. All these described above, have led to a good level of understanding of the clinical entity that can be summarized in the words “implant rehabilitation”. Having passed the first stages of evolution and with millions of implants placed worldwide there is a growing conversation over the past few years on who should be taught to be placing and restoring osseointegrated implants. The purpose of this lecture is to present the latest knowledge and ideas on whether implant prosthodontics should be taught on the graduate, undergraduate or both levels. The presentation will focus on various subjects like the similarities and differences in practicing clinical dentistry in different areas of Europe, comparisons of the teaching curricula of graduate and undergraduate programs, an insight on what the future dentist should have in terms of competences in what regards prosthodontics and finally some innovative ways of teaching implant prosthodontics.

Keynote Lecture No. 12 Implants and implant retained restorations: Friends or enemies? Nicola West, United Kingdom

The vast majority of peri-implant diseases are initiated by the accumula- tion of microbial biofilms on dental implants. These cause local inflammatory reactions in the marginal soft tissues. If the biofilms are not regularly disrupted by oral hygiene measures, the emergence of pathogenic spe- cies arise, which can lead to peri-implant mucositis. The prevalence of peri-implant mucositis is 43% and peri-implantitis 22%. The persistence of peri-implant mucositis leads to the development of peri-implantitis in susceptible individuals. Easily cleansable implant retained prostheses are essential for the patient to maintain good oral hygiene. There are some recommendations for clinical practice: 1. Patient’s risk assessment prior to implant placement is essential. 2. Once peri-implantitis is present the bone loss progresses very quickly and it is difficult to stabilize. 3. Long-term success of implant treatment is multifactorial and primarily depends on satisfactory maintenance of peri-implant tissues health. 4. The dental team is responsible for routine maintenance of the implant. 5. Patients should be fully educated on their own responsibilities regarding the correct oral hygiene, home-care techniques and the effect of dental plaque on the long-term success of implants. 6. Patients who present with higher risk or susceptibility (diabetes, smokers, history of periodontal disease) should be fully made aware of the implications of the risks and their need for systematic professional maintenance. 7. Clinicians are also required to screen their implant cases by periodic auditing of outcomes based

19 39th Annual Conference of the European Prosthodontic Association on their implant log books. During this lecture, several common clinical situations will by discussed

Keynote Lecture No. 13 The undergraduate and postgraduate studies in the university clinic of dentistry of Vienna Anna Knaus, Astrid Skolka, Austria

The study of dentistry is divided into 3 sections, the 3rd part is composed of a preclinical part, including the prosthodontic bases (8th semester) and a clinical part (11th and 12th semester). In the preclinical part, all the processes necessary for the prosthetic diagnostic and therapy should be trained. This is anamnesis, occlusal index, clinical examinations condylography, cephalometrics, impressions, different bite registrations, fabrication of casts and articulator-mounting. The theoretical knowledge and practical skills for creating high-quality dental single restorations, bridges and implant supported restorations are taught. In this section the students get to know the contents of the fixed and removable prosthetics, both theoretically and practically. The preclinical practical training is very intense, because all the bases of fixed and removable prosthetics are taught. The clinical part starts in the 10th semester, the prosthodontic patients are treated by students in the 11th and 12th semester. 90 percent of the patients of the dental school are complex cases. Most of them need pre-therapy and the treatment takes more than 2 semesters. Students can´t get enough experience in the treatment of complex cases during their studies. Therefore we offer the postgraduate Master of Science in Prosthetics which is also presented in this lecture. In the 11th and 12th semester, the students have to treat. The diagnostic findings are used to design the diagnostic wax-up. This has a double function: on one hand it is a part of the diagnostic package, on the other hand it is the first therapeutic step. The wax-up is helpful to answer the question concerning the compatibility of the patient´s chief complaint with the dentist´s requirements in the prosthetic rehabilitation. Extended diagnostics could avoid some unpredictable problems during therapy. The different diagnostic steps – starting with the anamnesis continuing with the diagnostic wax-up and resulting in an individual treatment plan – are introduced in this part of the lecture and its importance is supported by practical examples. The diagnostic findings, which are explained in part 1, result in the design of an individual treatment plan for each patient. The second part of the lecture concerns the determination of the occlusal concept and its implementation in the prosthetic rehabilitation. Difficult occlusal circumstances, caused by severe attrition, periodontal disease, extreme vertical dimension and craniomandibular dysfunction are analysed and the prosthetic solutions are discussed. Well documented case reports illustrate the implementation of the individual treatment plan starting with the pretherapy up to the recall. Different options of the prosthetic rehabilitation – fixed and removable solutions – are presented. Sometimes medical or economic reasons make a compromise in the treatment plan necessary. The difficulties finding a compromise which satisfies both – the chief complaint of the patient and the dentist´s expectation – will be discussed.

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Keynote Lecture No. 14 Implant maintenance and soft tissue management: Critical factors for long-term success Juliette Reeves, Switzerland

The continuing success and survival of each implant placement is de- pendant upon the provision of a long-term maintenance and support program. This presentation will provide delegates with up to date knowledge and current concepts in the care and maintenance of implants and the surrounding periodontal tissues. A review of debridement and disinfection techniques is presented along with complications and risk factors for the implant patient. Goals of the lecture: 1. To provide an overview of implant tissue anatomy and biological seal. 2. To identify implant surface characteristics and different debridement techniques. 3. To understand the etiology and management of peri-mucositis. 4. To develop protocols in the care and maintenance of the implant and supporting tissues. 5. To consider the complications and risk factors in the long-term maintenance of the implant patient. 6. To provide the patient with an effective bespoke homecare strategy.

Keynote Lecture No. 15 Classical and computerized modern implant-prosthetic rehabilitation Norina Forna, Romania

Classical techniques are landmarks in any implant-prosthetic rehabilitation by taking in consideration correct assessment of general health, loco- regional and local status of the patient. In this context limitations offered by classical techniques require modern computerized systems approach, especially those computerized systems that can indicate where and how we can apply an implant-prosthetic solution. Modern techniques such as robotized systems specify the exact position of implants and prosthetic solutions related to natural teeth. For pre- dicting future prosthetic implant solutions wax-up and mock-up are used. Any bone reconstruction must precede the implant insertion and it will be made considering the edentulous bone volume that reproduce the normal ridge in the area. Implant-prosthetic rehabilitation requires preparation of all absolutely necessary preprosthetic steps for a viable implant-prosthetic rehabilitation. Success is governed by the rigour and accuracy of the steps previously planned.

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Keynote Lecture No. 16 The prosthodontic dilemma in restoring the periodontally – compromised patient: Mainte- nance of compromised teeth or extraction and implant replacement Alberto Fonzar, Italy

In the last twenty years, implant therapy has changed the patient’s treatment plan, at times in a radical manner. Saving extremely compromised teeth by using “traditional therapies” (endodontics, periodontics, prostheses etc.) seems not only to have become more and more obsolete, but no longer justifiable from a cost-benefit ratio, or from expections of success over the long term. But is this approach really better than the “old one”? And if so, is it better in all patients? The aim of this lecture is to provide an answer to these by carefully analyzing the literature and presenting several clinical cases and the personal own data, in an attempt to evaluate the cost-benefit ratio not only from an economic, but also from a biological point of view. Attendee will learn: 1. The benefit but also the limits of periodontal prosthetics and implant therapy in the rehabilitation of patients affected by severe periodontal disease. 2. To carefully evaluate the cost/benefit ratio in both economical and biological point of view. 3. To differentiate between dogmas and what is really fundamental for a long-term successful treatment. 4. To consider the patient as the protagonist of treatment plan.

Keynote Lecture No. 17 Complete reconstruction of the dentition using dental implants Antonín Šimůnek, Czech Republic

The authors describe their own therapeutic protocol, in which the hopeless natural dentition is replaced by maxillary and mandibular fixed full- arch bridges. All operations proceed in local anesthesia and in an outpatient setting. During the 15-month treatment period the patients have fixed provisionalizations. This therapeutic protocol consists of 5 steps. First, remaining (1) maxillary and (2) mandibular teeth are removed. Transitory implants are immediately inserted and immediately provisionalized with cement-retained bridges. (3) After 5 months the bone is healed and insertion of 8 “permanent” implants in the maxilla with bilateral sinus lift follows. The central 6 implants are immediately loaded with screw-retained temporary bridge. (4) The next step is a placement of 5 interforaminal implants and their immediate loading with screw-retained mandibular temporary bridge. (5) The last step is manufacturing of lower and upper screw-retained final bridges with CAD/CAM frameworks. At the workplace of the authors this protocol has been carried out since 2006 and due to its high effectivity and success rate it became a part of their daily implantological practice.

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Keynote Lecture No. 18 Intrusion of supraoccluded molars with temporary anchorage devices before a prosthetic reconstruction Josef Kučera, René Foltán, Martin Tomeček, Czech Republic

Adult patients with missing lateral teeth and consequent supraocclusion of antagonist teeth present a great challenge for the treating prosthodontist or implantologist. Supraoccluded molars may approach the gingiva and alveolar crest in the opposing jaw to such an extent, that it makes any prosthetic reconstruction impossible. The treatment options thus depend on the severity of the supraocclusion. In severe cases, either extensive grinding with root canal treatment or extraction of supraccluded tooth may be the only possible treatment options. Orthodontic intrusion with the help of temporary anchorage devices (miniplates, orthodontic miniscrews) brings a viable, problem-focused alternative, which does not require comprehensive orthodontic treatment and provides predictable results. The aim of this lecture is to introduce this method on severe cases of patients with molar supraocclusion and discuss some clinical aspects of molar intrusion, including the retention of the results. Acknowledgements: Supported by national grant agency fund: IGA MZ NT/14189 - 3/2013.

Keynote Lecture No. 19 Digital reconstruction and interdisciplinary cooperation in surgical design and simulation – novel approaches in reconstruction and rehabilitation of head & neck oncology patients Suresh Nayar, Canada

Management of head and neck cancer is increasingly being carried out with microvascular flaps to reconstruct both hard and soft tissue deficits. Functional oral rehabilitation for these patients has posed a real challenge to both prosthodontists and head & neck surgeons because of the complexity of the defects and the reconstructive requirements. The use of bone containing free flap transfer techniques has significantly improved jaw reconstruction but complete dental rehabilitation continues to be a challenge for this cohort of patients. One of the barriers to attain oral rehabilitation with osseointegrated implants is achieving accurate osteotomies and optimal insertion and positioning of the bone flaps. The advent of advanced digital technologies that could be used to plan the reconstructions, has allowed the surgery involving both hard and soft tissues transfers to be raised to new levels of precision and accuracy. These digital technologies have allowed convergence of imaging, digital surgical simulation for bone and soft tissue transfer and implant installation simulation. To achieve this level of sophistication in surgical reconstruction and oral rehabilitation for head and neck cancer patients, it is imperative that the management is a team affair of a group of highly trained specialists in various fields including prosthodontics, head and neck surgery, surgical design and simulation, dental lab technology among others. This presentation will share with the delegates, how our institution has achieved this interdisciplinary cooperation and how this collaboration achieves the end result.

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Keynote Lecture No. 20 Agressive periodontitis and orthodontic treatment Ivo Dřízhal, Zdeněk Hofman, Uve Engels, Czech Republic

Authors demonstrate collaboration of periodontologist and orthodotist in the treatment of agressive periodontitis on 3 cases. Team collaboration is still not common in our dental surgeries. To develop well working team – it means to have empathy to understand the different topics and also to introduce my subject for other members of team. Demonstrated cases are opening the way for a less usual treatment plan which is giving surprisingly nice esthetic results. The problem is in selection of patiens, because the long-term perfect collaboration is mandatory. Also the finantial aspect is limitation. The paper would like to focuse on the possibility to explore the progress in dental specialities for treatment of our patients, especially for the group looking for high standard. We would like to stress that this type of treatment is lasting not many months but years. The results are positive.

Keynote Lecture No. 21 Digital technology – new materials, new possibilities, unlimited indications? Irena Sailer, Switzerland, USA

Digital impressions and computer-aided manufacturing of restorations steadily gain in importance within restorative dentistry. Irrespective of the fact that digital impressions have been introduced to dentistry more than 30 years ago with the development of the Cerec CAD/CAM system, their application in daily clinical practice was not very frequent – until recently. Today, a high number of intraoral scanners and associated CAD/CAM procedures are available. One of the factors raising the attractiveness of computerized procedures is the high variety of new restorative materials which were introduced for the computerized manufacturing. High strength ceramics, lithium-disilicate glass-ceramics or non-precious alloys are already well established as restorative materials. New hybrid materials like e. g. nano-ceramics even promise to be long-lasting, highly esthetic and less costy. They can be used in the monolithic stage, and processed chairside in the dental practice. An increase in the application of these monolithic tooth – and/or implant – born restorations can be observed in daily clinical practice. Still, the literature on their outcomes is very scarce. The lecture will critically evalulate the possibilities that the new technologies offer to the practician, and will highlight whether or not they are unlimited.

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Keynote Lecture No. 22 Robotic prosthodontics Roman Šmucler, Czech Republic

We feel humans are unable to assemble cars accurately with the required millimeter precision. Why do we use people with their eyes disorders and unstable hands for something so incredibly demanding on the accuracy, such as a preparation of a dental crown? Are humans really capable to grind with a micrometer precision? Not really. So, we have to replace them in the mechanical work and we have to give them just what they can really do, e. g. diagnosis, treatment planning and final controls. But we do not have the ideal technology, yet… There is no secret and no surprise that the precise work of skilled dental technicians is becoming replaceable by CAD/CAM machines. But because currently the prosthodontists have to work on live and movable persons, we shall address the safety issue first, before machines can replace humans. But the benefits of robots such as their ability to work 24/7, long lifetime and the economy of scale will outweigh one day. The usual team of dentist and his assistant will be potentially expanded by a robot that can take part of whole treatment plan. A larger number of robots in the office can greatly increase performance, reduce the cost of treatment and give access to high quality care to more patients. From this moment we are still far away. We have already first successful studies. Journey has begun thanks to the experience of dental laboratories. The aim of this lecture is not to scare skillful and experienced prosthodontists that they will lose their job but to show the way for the possible development and give inspiration for research.

Keynote Lecture No. 23 New horizons in implant prosthodontics: CAD/CAM-individual implant abutments Peter Gehrke, Germany

Predictable osseointegration has taken the role of implant dentistry beyond the mere restoration of function for the compromised edentulous and partially edentulous patient to an accelerated and esthetic treatment approach for implant-supported restorations. Despite the predictable longevity of implant suprastructures, there is an ongoing interest to improve the implant restorative treatment and outcome. One of the recent developments is the application of computer-aided design and computer-aided manufacturing (CAD/CAM) to produce implant abutments and frameworks from metal or ceramic materials. Optical scanning of master casts will prosthetically extend the scope of abutment and restoration fabrication in removable and fixed prosthodontics. Custom abutments are available in Y-TZP zirconia and titanium and can be more predictably designed to re-create the desired supporting crown orientation and morphology. This facilitates the formation of anatomical gingival topography and coronal contours for prosthetic replacement. They offer natural emergence anatomy; proper spatial design at the cervical margin; sufficient occlusal reduction; and proper axial angulation for ideal design. The presentation will critically evaluate the rationale of CAD/CAM technology in implant restorative dentistry and will highlight the natural symbiosis of a functional and esthetic treatment approach, considering novel techniques and their material aspects.

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Keynote Lecture No. 24 Integration of new materials and concepts in interdisciplinary implant procedures Albert Waning, The Netherlands

Patient satisfaction with dental procedures is very dependent on expectations. New provisional materials are making it increasingly easy to produce an accurate mock-up of the restorations in the mouth of the patient. Extended use of these allow the patient to get used tofeeling, shape, size and phonetics before committing to expensive, definitive restorations. The increasing use of new CAD/CAM resin technology makes the definitive restorations relatively inexpensive, within reach of most patients and relatively easily exchangeable in case of any miss match. Providing implant supported supra-structures becomes very much an interdisciplinary cooperation between implantologist, laboratory technician and prosthodontic dentist.

Keynote Lecture No. 25 Just screw it? Screw – retained versus cemented reconstructions Petr Barták, Roman Šmucler, Czech Republic

Cement it or not cement? This is the key question of implant prosthodontics in last decades. Frequently opposite answer is confusing for many clinicians. We have two true but contradictory axioms. Loosening of different screws is one of the most common causes of implant treatment failures and cement remnants are an important factor for the development of peri- implant diseases. On the other hand we must keep in mind aesthetics and resistance of our reconstructions. Synthesis of these two real facts is as “simple” as synthesis of physical theoretical system of Bohr and Einstein. To make the situation more confusing, some authors promote a hybrid solution. The aim of our lecture is to provide a literature overview, to analyze strong and weak sides of both solutions, to show different clinical and technological options and finally we want to present our results and decision criteria for daily praxis.

Keynote Lecture No. 26 Czech archaeological explorations in Egypt and Sudan Miroslav Verner, Czech Republic

It is more than 50 years since the International UNESCO Campaign to save the monuments of Nubia began and, ever since that time, the Czech archaeological team has been exploring, restoring and saving the Ancient Egyptian monuments. Our work has made an important contribution to the world historical and cultural heritage. The long-standing flagship of the Czech archaeologists in Egypt has been research in the pyramid field at Abusir, but they also work in the Egyptian Western Desert and, recently, in Sudan. Archaeological discoveries made by the Czech team have not only enriched Egyptian museums but they have significantly contributed to the better knowledge of the history of Ancient Egypt and its ancient culture.

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7. WORKSHOP LECTURES

Workshop No. I Fibre reinforced composites in treatment with dental implants Otakar Dubec, Czech Republic

The workshop brings an understanding the principles of application adhesively bonded fibre reinforced composite bridge, the effect of fibre reinforcement on durability of composite crown and large composite restorations and post endodontic treatment with minimally invasive system of flex- ible pins. For all topics the theoretical background and clinical advantages will be discussed as well as practical training for all topics will be a part of this workshop. Partner: ADM, a.s

Workshop No. II Microscopic dentistry in fixed prosthodontics Daniel Ott, Czech Republic

This workshop is focusing on: 1. Improvement of finishing line in crown and veneer preparation, 2. Making the impression technique more precise, 3. Results of preparations, impressions and crown reconstructions are more predictible. Hands-on course applying the dental microscopy or loupes in the precise veneer, overlay and crown preparation using fantom composite teeth. Possibility of the impression results control under the high magnification will be provided. Equipment: Zeiss dental microscopes and loupes, KaVo and A-dec fantoms, composite teeth, silicon A or polyether impressions. Partners: KaVo Kerr Group, EveryDent, s.r.o.

Workshop No. III Modern hygienic methods and dental implants –“Philips Sonicare AirFloss Ultra“ Kateřina Ciklová, Jana Křepelková, Czech Republic

Excellent oral hygiene prolongates prognosis of dental implants in the oral cavity. Oral hygiene is the best prevention of possible implant failure. Dental hygiene is rightfully seen as an effective tool preventing diseases of hard dental tissues and periodontium, demands for tools to control dental plaque are rising. What used to be seen as the best option in the past is now swept aside and more and more sophisticated methods of oral hygiene are getting ahead. Demands are coming not only from the specialists in dentistry but also from the patients themselves. This workshop looks into application of the Philips Sonicare AirFloss Ultra as an innovative solution for individual needs in every type of patient. Understanding the nature of anaerobic and aerobic flora in etiology of periodontal and periimplant pathology inspired development of a tool combining removal dental plaque with water with an aero- sol rich in oxygen that gets into interdental and interimplant spaces. The workshop brings an understanding the principles of patented technology Microburst – combination of droplets of water and air and their advantages. Finally, it will offer you chance to get to know and experience this technology yourself in form of brush-test. Every participant absolving brush-test will get the Philips Sonicare AirFloss Ultra as a present. Golden Partner: Philips Česká republika, s.r.o. 27 39th Annual Conference of the European Prosthodontic Association

8. ORAL PRESENTATIONS

Oral Presentation No. 1 Comparison of cytokine production by SaOS-2 and immunocompetent cells cultivated on alginate surfaces doped with calcium phosphates

Lucie Himmlová1, Dana Kubies2, Jiřina Bártová1, Elena Filová3, Lucie Bačáková3 1Charles University in Prague, First Faculty of Medicine, Department of Stomatology, Czech Republic 2Academy of Sciences of the Czech Republic, Institute of Macromolecular Chemistry, Prague, Czech Republic 3Academy of Sciences of the Czech Republic, Institute of Physiology, Prague, Czech Republic

Purpose: The immune response of the host tissue to a tested biomaterial contributes to determination whether the proposed material meets prerequisites for its successful application in implantology. Considering in vitro evaluation, appropriate testing methods should be chosen. Connective tissue cell line SaOS-2 and immunocompetent (mononuclear) cells obtained from buffy coats re- present the cell types that are involved in wound healing, as well as the response of the body to the implant. However, their cytokine response to the identical implant material can differ. Materials and Methods: In the present work, alginate hydrogel coatings doped with inorganic hydroxyapatite (Ti/ALG/HAP) or β-tricalcium phosphate (Ti/ALG/TCP) nanoparticles on Titanium grade 2 (Ti) were prepared. Both cell types mentioned above were used to evaluate the cytokine production when cultivated on the proposed coatings. The pristine Ti and alginate (ALG) served as control surfaces. Cytokine production was assessed by the multiplex proteomic analysis Ray- Bio Human Inflammation Array 3 (RayBiotech, USA) preset for 40 cytokines after 3 and 7 days of cultivation. Results: Mononuclear cells produced preferentially factors of nonspecific immunity (IL-6, IL-8, RANTES, MCP-1 and MIP) and in doses higher than detected for the positive control of the RayBio array representing 100%; the cytokine production declined in the order Ti/ALG/HAP → Ti → Ti/ALG/ TCP → Ti/ALG. SaOS-2 cells produced almost all selected cytokines, but their expression reached only up to 30% of the positive control of the array. The only one exception was TIMP-2 expressed in a higher extent compared to mononuclear cells (reached above 75% of the positive control). Moreover, no significant difference between Ti/ALG/HAP and Ti/ALG/TCP surfaces was observed. Conclusions: Both cell types produced a different spectrum of cytokines. The immune response of mononuclear cells showed differences between tested materials, whereas SaOS-2 cells weren’t sufficiently sensitive. Therefore, besides SaOS-2 cells, mononuclear cells should be also considered for in vitro evaluation of overall inflammatory response induced by presence of the implant. This work was supported by IGA MH CR, project No. 13297-4, by research programme PRVOUK P28/LF1/6 of MSMT CR and by the European Regional Development Fund (project BIOCEV No. CZ.1.05/1.1.00/02.0109).

Oral Presentation No. 2 Evaluating denture hygiene in head and neck oncology patients

Petros Mylonas, P. Sparks, S. G. S. Ellis University of Birmingham, United Kingdom

Purpose: Oncology patients who have undergone prosthetic oral rehabilitation should receive oral and denture hygiene instructions (DHI) and demonstrate adequate self-care. They are at increased risk of dental disease compared to the general population, especially following radiotherapy. The

28 39th Annual Conference of the European Prosthodontic Association aim of the study was to analyse the quality of denture hygiene in head and neck cancer patients and improve current practice. Materials and Methods: The Denture Cleanliness Index (DCI, Mylonas et al 2014), used previously in general dental practice and a Prosthodontics department at a teaching hospital, was utilised to evaluate the quality of prosthesis hygiene of patients treated within the Head and Neck Oncology Unit at Poole Hospital (n = 33). Baseline DCI scores were obtained and patients were given tailored DHI. Patients’ DCI scores were reviewed after 1-month and at 3-months. Acceptable denture hygiene was defined as a DCI score 2 or less. Results: The mean age of patients treated was 70.4 years, ranging between 50 to 86 years old, 54.5% (n = 18) were male and 45.5% (n = 15) female. Results at baseline showed that only 24% (n = 8) of patients had DCI scores of ≤2, which improved to 68% (n = 17) after 1-month, and after 3-month review increased to 87% (n = 15). Conclusions: Providing tailored DHI and utilising the DCI resulted in a demonstrable improvement of denture cleanliness over a 3-month period of review; the first reported case over the medium term. The DCI worked well as an objective clinical measurement and patient education tool providing determination of current denture hygiene status and assessing, longitudinally, patient compli- ance to DHI.

Oral Presentation No. 3 Temporomandibular joint disorders from perspective of craniometric and myographic parameters

Maksim Yurchenko, Hana Hubálková Charles University in Prague, First Faculty of Medicine, Department of Stomatology, Czech Republic

Purpose: Understanding the development of temporomandibular joint disorders is an important condition for early diagnosis and successful treatment. Nowadays, it is well known that occlusion imbalance and muscles play an essential role in the development pathology. The aim of this research is to estimate the connection between temporomandibular joint disorders and occlusion plain inclination as well as the state of chewing muscles. Materials and Methods: The research was based on examination of the group of 60 people, which consisted of 32 healthy volunteers and 28 patients with temporamandibular joint disorders (disc displacement with reduction). The examination consisted of fabrication of study models, kinesiog- raphy, myography of chewing muscles, vibrometry and radiography of temporomandibular joints, teleradiography in two plains (coronal and sagittal). Subsequently, the x-ray films have been analyzed via Dolphin Imaging Program and statistically evaluated. Results: The results of the research demonstrate the significant dissimilarities between craniometrical and myographic parameters of healthy volunteers and patients with temporomandibular joint disorders. The most indicative distinction was revealed in the asymmetry of occlusion plain which proves the essential impact of this parameter on the emergence of pathology. It was also noticed that the pathology of temporomandibular joint could be in the first place connected with the tones m. masseter. Conclusions: Determination of the average craniometrical and myographic figures is of profound importance mainly in treatment of the patients with temporomandibular joint disorders as well as for the prevention of these disorders.

Oral Presentation No. 4 Short dental implants success in edentulous posterior maxilla

Igor Linetskiy, Vladyslav Demenko, Larysa Linetska, Hana Hubálková, Oleg Yefremov 29 39th Annual Conference of the European Prosthodontic Association

Charles University in Prague, First Faculty of Medicine, Department of Stomatology, Czech Republic

Purpose: The purpose was to evaluate the influence of available bone height and implant dimensions on load-carrying capacity of implants in posterior maxilla. Materials and Methods: 3.3–5.4 mm diameter, 4.5–8.5 and 13.5 (reference) mm length implants were studied. 3-D models of maxilla with implants were analyzed in FE software ANSYS 15. 20- node FEs total number was up to 2,920,000. 118.2 N oblique loading was applied. Ultimate functional load (UFL) was proposed as a criterion to evaluate the influence of bone size and implant dimensions on implant load-carrying capacity. To calculate UFL values, 100 MPa ultimate strength of cortical bone and von Mises strength theory were used. Results: Implant load-carrying capacity was substantially dependent on implant diameter and available bone height. Comparing to the smallest implant, UFL increase for the largest implant was 2.8 fold. Diameter increase from 3.3 to 5.4 mm caused UFL increase from 97% for 4.5 mm implant to 75% for 8.5 mm implant. Length increase from 4.5 to 8.5 mm resulted in UFL rise from 64% for 3.3 mm implant to 43% for 5.4 mm implant. UFL reduction was also studied relative to conventional implants. For 4.5, 5.5, 6.5, 7.5 and 8.5 mm implants, it was 49%, 40%, 34%, 27% and 21%, respectively. Conclusions: Bone stresses can be distributed efficiently using short implants by selecting proper diameter and length, without bone graft in poor bone sites. Load-carrying capacity of short implants greatly depends on their size. Implant size is of utmost importance for clinicians in implant selection.

Oral Presentation No. 5 The virtual prosthodontic patient: Integrating facial, intraoral and CBCT datasets

Bassam Hassan, Bea Gimenez Gonzalez, Ali Tahmaseb, Daniel Wismeijer Academic Centre Dentistry Amsterdam (ACTA), The Netherlands

Purpose: To report clinical outcomes of a novel digital virtual patient workflow combining fully guided immediate implant placement with CAD/CAM fabricated, screw-retained, implant-supported provisional prosthesis in full mouth fixed-prosthesis upper cases. Materials and Methods: Twenty upper edentulous patients in need for a complete implant-retained fixed prosthesis were recruited. Pre-operative extraoral facial scans (Pritidenta, Leinfelden, Ger- many), digital intraoral impressions (TrueDef, 3M ESPE, Germany) and CBCT (Accuitomo 170, Morita, Japan) were digitally combined using three-dimensional software tools to create a virtual patient replica. A complete CAD/CAM milled, screw-retained prosthesis based on the digital planning data was then fabricated for each patient (Avadent, Tilburg, The Netherlands). A surgical guide based on the ideal virtual prosthetic setup (CoDiagnostix 9, DentalWings, Dusseldorf, Germany) was then milled and supported on three mini-implants. Fully guided implant placement using the Straumann® Guided Surgery system was performed and 5–6 implants in the edentulous upper jaw were inserted. The provisional prosthesis was subsequently immediately loaded. Digital extra- and intra-oral scans were repeated following prosthesis insertion and clinical fit between preoperative planning and post-operative result was assessed. Results: Twenty provisional prostheses on 5–6 implants were placed with clinically acceptable fit. Following loading, prosthesis failure was noted in three cases. Conclusions: Preliminary results of this novel digital surgical/prosthetic workflow combining the information from facial, intraoral and CBCT scanners are promising. Further research is needed to address the issues of guided surgery accuracy and the precision of the registration procedure of facial, intraoral and CBCT information and the virtual prosthetic setup design.

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Oral Presentation No. 6 Retrospective study of extensive ceramic veneers – 7 year results

Sven Rinke1, Anne-Kathrin Schmidt2, Xenia Schulz3, Dirk Ziebolz4 1University Medical Centre Goettingen, Department of Prosthodontics, Germany 2Private Practice, Hanau, Germany 3University Medical Centre Goettingen, Department of Medical Statistics, Germany 4University Medical Centre Leipzig, Department of Restorative Dentistry & Periodontology, Germany

Purpose: Retrospective evaluation of extended anterior ceramic veneers in the upper and lower jaw 7 years after placement in a private practice. Materials and Methods: 33 patients (19 female/14 male) were restored with adhesively luted extended veneers that were fabricated using heat-pressed ceramic (Cergo, DeguDent, Hanau/Ger- many). A single dentist restored 107 teeth (maxilla, n = 71; mandible, n = 36). Adhesive cementation was performed using an etch and rinse adhesive (Optibond FL, Kerr Hawe) and a dual-curing composite cement (Variolink, Ivoclar Vivadent/Calibra, Dentsply DeTrey). Results: After 7 years, the Kaplan-Meier survival rate (in-situ criteria) was 93.6% (95% – Confi- dence interval [95%-CI]: 0.89; 0.98). The observed failures were caused by ceramic fractures for 7 restorations and biological failure for 1 restoration. Among the restorations, 84.3% (95%-CI: 0.76; 0.93) were in still service without any required clinical intervention and were rated successful after 7 years. Interventions were necessary in 14 cases (8 recementations, 2 endodontic treatments, 2 composite fillings (caries), 2 polishings of minor fractures). The clinical performance was not influenced by the veneer position (maxilla/mandibula, survival p = 0.56/success p = 0.30). The veneers that covered surfaces with over 50% exposed dentine exhibited a significantly increased risk (Haz- ard ratio 3.71, p = 0.0041) for requiring a clinical intervention; however, no effect on the survival rate for these veneers was observed (p = 0.35). Conclusions: Following 7 years of clinical service, extended anterior veneer restorations made using a pressable ceramic exhibited comparable survival and success rates for the upper and lower jaw. Large areas of exposed dentin (>50%) were associated with lower success rates.

Oral Presentation No. 7 Effect of thermal and mechanical cycling on dentin bond strength

Haluk Baris Kara1, Tugrul Sari2, Ozgun Yusuf Ozyilmaz1, Pelin Inan Kurugöl1, Ozlem Kara2, Aslihan Usümez2 1Istanbul Medipol University, Department of Prosthodontics, Turkey 2Bezmi Alem Vakif University, Department of Prosthodontics, Turkey

Purpose: The aim of this study is to evaluate the effects of cyclic thermal and mechanical loads on dentin bond strength of a self-etch resin luting cement. Materials and Methods: Inlay cavities were prepared on eighteen mandibular third molars (6 × 3 × 2 mm). Restorations were fabricated by using feldspatic porcelain (Vita VM9). Bonding achieved by using a dual-cure, self-etch resin luting cement (Clearfil Esthetic Cement). The teeth were then randomly divided into 3 groups: Group I: Control group (no thermal or mechanical cycling). Group II: Thermal cycling (thermocycling for 5,000 cycles). Group III: Mechanical load cycling (1,200,000 cycles). Two I-shape-sectioned longitudinal cuts were made from each tooth (n:12) and a total of 36 specimens were subjected to tensile forces at a crosshead speed of 1 mm/ min, and the maximum load at fracture was recorded. The fracture site was observed with a stereomicroscope (Olympus, SZ-PT) to identify the mode of failure. A tooth from each cementation group was selected and inter- faces observed under SEM (435 VP; Leo).

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Results: One-way ANOVA has revealed that there were significant differences among the groups (p < 0.05). Tukey’s HSD analysis showed that; the mean MTBS of Group III was significantly lower than Group I and Group II (p < 0.05). There were no significant differences between Group I and Group II (p > 0.05). Conclusions: Within the limitations of this study mechanical loads seem to be effective on bonding stability while temperature alterations were not significantly influent. Additionally, the principal failure type is interfacial for all groups.

Oral Presentation No. 8 Micro-shear bond strength according to dentin cleansing methods before recementation

Simge Taşar, Mutahhar M. Ulusoy, Gökçe Meriç Near East University, Faculty of Dentistry, Department of Prosthodontics, Nicosia, Turkish Republic of Northern Cyprus

Purpose: The aim of this study was to determine the efficiency of Erbium, Chromium: Yttrium- Scandium-Galium-Garnet (Er,Cr:YSSG) laser in different output powers for removing permanent resin cement residues and therefore its influence on micro-shear bond strength (µSBS) compared to other cleaning methods. Materials and Methods: 90 extracted human molars were sectioned in 1 mm thickness. Resin cement was applied to surface of sliced teeth. After the removal of initial cement, 6 test groups were prepared by various dentine surface treatment methods as follows: no treatment (group 1), ethyl- enediaminetetraacetic acid (EDTA) application (group 2), Endosolve R application (group 3), 1.25 W Er,Cr:YSGG laser irradiation (group 4), 2 W Er,Cr:YSGG laser irradiation (group 5) and 3.5 W Er,Cr:YSGG laser irradiation (group 6). The topography and morphology of the treated dentin surfaces were investigated by scanning electron microscopy (SEM) (n = 2 for each group). Following the repetitive cementation, µSBS between dentin and cement (n = 26 in per group) were measured with universal testing machine and the data were analyzed by Kruskal Wallis H Test with Bonferroni correction (p < 0.05). Fracture patterns were investigated by light microscope. Results: The efficiency of surface treatment methods was revealed by SEM. Mean µSBS±sd (MPa) for each group was 34.9 ± 17.7, 32.1 ± 15.8, 37.8 ± 19.3, 31.3 ± 12.7, 44.4 ± 13.6, 40.2 ± 13.2 respectively. Group 5 showed significantly difference from group 1, group 2 and group 4. Also group 6 was found statistically different from group 4. Conclusions: 2 W and 3.5 W Er,Cr:YSGG laser application were found efficient in removing resin residues.

Oral Presentation No. 9 Evaluation of shear bond strength of two resin cements on different CAD/CAM materials

Ozlem Ustun, Aslı Secilmiş, Isil Buyukhatipoglu University of Gaziantep, Health Science Institute, Turkey University of Akdeniz, Health Science Institute, Turkey

Purpose: This study investigated the bond strength of two resin cements (Panavia F 2.0; P and Multilink N; M) to different CAD/CAM materials: Resin nano ceramic (Lava Ultimate; LU), hybrid dental ceramic (Vita Enamic; VE), zirconia reinforced lithium silicate ceramic (Vita Suprinity; VS), and lithium disilicate glass-ceramic (IPS e.max CAD HT; IPS). Materials and Methods: CAD/CAM blocks were sectioned with a slow-speed diamond-saw sectioning machine with 2 mm thickness. Slabs were embedded in autopolymerizing acrylic resin (n = 12). Resin cements were applied on the surface of specimens. All specimens were stored in water for

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24 hours and subjected to 5,000 cycles of thermocycling. Bond strength was measured by means of the shear bond strength (SBS) test. Data were statistically analyzed by two-way ANOVA and Tukey LSD post-hoc tests. Results: The results of two-way ANOVA indicated that SBS values varied significantly depending on restorative materials, resin cements and the interaction of these factors (p < 0.05). LU-P group showed the highest bond strength for Panavia F 2.0 (p < 0.05). There were no significant differences between VS-P, VE-P and IPS-P (p > 0.05). IPS-M group showed the highest bond strength for Multilink N, it was followed by VS-M Group (p < 0.05). There were no significant differences between LU-M and VE-M (p > 0.05). Conclusions: The choice should be done carefully because SBS values varied significantly depending on resin cement and restorative material.

Oral Presentation No. 10 Bond strenght of composite resins to CAD/CAM fiber-reinforced composite blocks

Pinar Adimci, Yavuz Altintop, Ender Akan, Bora Bağiş Ağiş Izmir Katip Çelebi University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Nowadays, fibre reinforced composite (FRC) blocks for CAD/CAM restorations are introduced to dental market. The aim of this study was to evaluate the effect of different adhesive systems on the bond strength of composite resins to these materials. Materials and Methods: 60 FRC blocks (Trinia, Bicon LLC) samples were prepared for the study with the 5 × 5 × 2 mm dimensions, specimens were divided into six subgroups. Three of these groups were stored in a water bath for 24 hours for aging. Groups, which were aged (A) or non- aged (N), were treated with three different adhesive systems: One step-self etch (A1, N1) (Single Bond Universal, 3M Espe); Total etch (A2, N2) (Single Bond Universal); Two step-self etch (A3, N3) (Clearfil SE bond, Kuraray Dental). Then the surfaces were built up with composite resins (3 mm diameter and 3 mm length). The specimens were tested for shear bond strengths using universal testing machine. The fracture modes were evaluated and then results were statistically analyzed with one-way ANOVA and Tukey’s HSD test. Results: There were significant differences between groups N2 and N3, and between groups A3 and N3 (p < 0.05). There wasn’t any difference between A1 and N1, A2 and N2 (p > 0.05). The fracture modes were dominantly adhesive in all groups. Conclusions: The application of two step-self etch adhesive system may be beneficial for the bond strength of composite resins to FRC blocks comparing with the total etch system. Aging of FRC blocks have a negative effect on their bond strengths with composite resins when using the two step-self etch adhesive systems.

Oral Presentation No. 11 Effect of cement film thickness on the strength of all-ceramic crowns

Abdurrahman Şahinbaş, Erhan Demir, Gürcan Eskitaşçioğlu Yüzüncü Yıl University, Faculty of Dentistry, Department of Prosthodontics, Van, Turkey

Purpose: The purpose of this study is to investigate the effect of the cement film thickness on strength in different all ceramic crowns fabricated with CAD/CAM system. Materials and Methods: 9 groups, in which 12-units examples were produced from feldspathic glass ceramic (cerecblocs), lithium disilicate (e.max CAD) and nano-ceramic (Lava Ultimate) blocks, in the range of 100, 120 and 200 μ cement film thicknesses. Dental implant abutments with same diameter (4.5 mm) were used for supports of restorations. CAI/CAD/CAM system (Cerec AC) was

33 39th Annual Conference of the European Prosthodontic Association used to produce the restorations. For the measurement of resistance values was used a universal tester with 3 mm thick sphere. Results: Average strength values of feldspathic glass ceramic crowns were at 100 micron cement film thickness (A1 group) 556.4 N, at 120 micron cement film thickness (A2 group) 569.5 N and at 200 micron cement film thickness (A3 group) 624 3 N. Average strength values of lithium disilicate glass-ceramic crowns were at 100 micron cement film thickness (B1 group) 1235.8 N, at 120 micron cement film thickness (B2 group) 1066.8 N and at 200 micron cement film thickness (B3 group) 1060.7 N. Average strength values of nano-ceramic crowns were at 100 micron cement film thickness (C1 group) 1156.1 N, at 120 micron cement film thickness (C2 group) 1130.8 N and at 200 micron cement film thickness (C3 group) 1053.2 N. Conclusions: The cement film thickness increase was resulted with decrease in the strength values of lithium disilicate and nano-ceramic crowns and with increase in the strength values of feldspathic glass ceramic crown.

Oral Presentation No. 12 Effect of selective infiltration etching for resin cementation of zirconia

Merve Çakirbay Taniş, Canan Akay, Murat Şen Ankara, Turkey

Purpose: The purpose of this in vitro study was to evaluate efficiency of selective infiltration etching method on shear bond strength between zirconia and two resin cements; a conventional resin cement Variolink II and a MDP containing resin cement Panavia SA. Materials and Methods: 40 zirconia specimens (13 mm × 7.5 mm × 2.5 mm) (ICE Zirkon, Zirkon- zahn, Bruneck, Italy) were prepared and divided into two groups. Surface treatments were performed as following; group I: Sandblasting, group II: Selective infiltration etching. 40 composite cylinders (Tetric N-Ceram: Ivoclar Vivadent, Schaan, Liechtenstein) in 3 mm diameter and height were prepared. After application of surface treatments composite cylinders were cemented to zirconia surfaces using conventional resin cement Variolink II (Ivoclar, Vivadent AG, Schaan Liechtenstein) or MDP containing resin cement Panavia SA (Kuraray, Osaka, Japan). After cementation procedure specimens were stored in 37 ºC distilled water for 24 hours. Following water storage shear bond strength test was performed at a crosshead speed of 1 mm/min in a universal test machine (Lloyd- LRX; Lloyd Instruments, Fareham, UK). Then statistical analyses were performed. Results: Highest shear bond strength values were observed in Group II cemented using Panavia SA resin cement while lowest shear bond strength values were observed in group I cemented using Variolink II resin cement. Conclusions: Use of selective infiltration etching method seems a promising surface treatment method for resin cementation of zirconia ceramics. MDP monomer containing resin cement improves resin bonding of zirconia ceramics.

Oral Presentation No. 13 Effect of femtosecond laser angles and shapes to zirconia-resin bond strength

Yener Okutan1, Ismail Kilic1, Hamdi Sukur Kilic2, Yasemin Gundogdu2, Munir Tolga Yucel 1Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Konya, Turkey 2Selcuk University, Faculty of Science, Department of Physics, Turkey

Purpose: Femtosecond (Fs) laser is an innovative laser technology for modifying ceramic surface. The purpose of this study was to evaluate the effect of angles and shapes formed by femtosecond laser on surface roughness (Ra) and shear bond strength (SBS) of zirconia ceramic.

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Materials and Methods: Seventy specimens were prepared from monolithic zirconia (Prettau) and randomly divided to 7 subgroups (n = 10) according to different surface shapes (square, circular, spiral) and laser angles (30° and 90°). Ra values were measured using a profilometer and SEM images were taken at 500x magnification. Self-adhesive resin cement (Rely X U200) was bonded to specimens using a Teflon mould. Specimens were stored in distilled water at 37 °C for 24 hours and then thermal cycled. SBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Failure modes (adhesive, cohesive or mixed) evaluated for each specimen. Data were statistically evaluated using one-way ANOVA, Kruskal-Wallis, Tukey HSD and Mann- Whitney U (p = 0.05). Results: Control group showed significantly lower Ra and SBS values compared with laser groups (p < 0.05). Circular shaped groups showed lower Ra and SBS values compared with spiral and square in each 30° and 90° groups (p < 0.05). 30° laser groups showed higher SBS values compared with 90° groups. Conclusions: Based on the results it can be concluded that, femtosecond laser is effective on surface roughness and bond strength between zirconia and resin cement. Also angles and shapes formed by femtosecond laser are important factors on bond strength and surface roughness.

Oral Presentation No. 14 Contemporary view on dental materials and MRI

Hana Hubálková, Igor Linetskiy, Marie Bartoňová, Jindřich Charvát, Jiří Mazánek Charles University in Prague, First Faculty of Medicine, Department of Stomatology, Czech Republic

Purpose: Magnetic resonance imaging (MRI) is of significant importance for diagnostics in many fields of medicine. Since its first application in clinical practice in 1980’s, over 300 millionMRI examinations have been performed. MRI has also certain shortcomings. One of them is the interference between magnetic resonance (MR) scanner magnetic field and metallic materials. As for dental objects, this interference mostly manifests as artefacts, which look like image distortion, addition or deletion of graphic information, sometimes as a noticeable rim around metallic object images. Artefacts obstruct MRI assessment, which may lead to patient’s misdiagnosis. Various studies of dental alloys indicated that there is an enormous difference in their MR issues because materials composition differs significantly, which as well as internal structure, determine their magnetic properties. Secondly, artefact size directly depends on MR magnetic field. Furthermore, some sequences are more prone to metals, which lead to larger artefacts. Besides, metallic object shape and size as well as its orientation in magnetic field influence image distortion. Materials and Methods: This presentation summarizes contemporary data on MRI image distortions due to dental metallic materials. Results: Examination of all materials showed that all of them caused artefacts of different extend. The largest distortions were observed on MR images of cobalt-chromium and nickel-chromium alloys, stainless steel and aluminium bronzes. Conclusions: Since MRI is a rapidly developing diagnostic modality with increasing magnetic field strength, artefacts remain a serious issue, which requires intent attention from researchers and clinicians. Newly developed materials should be tested for MRI interactions.

Oral Presentation No. 15 Effectiveness of a universal adhesive on bond strength to dentin

Erhan Comlekoglu, Mine Dundar Comlekoglu, Ece Sengun, Gizem Yaman Ege University, School of Dentistry, Department of Prosthodontics, Bornova, Izmir, Turkey

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Purpose: To evaluate the micro-shear bond strength (MSBS) efficacy of a new universal adhesive to enamel and dentin surfaces with different dentin drying modes. Materials and Methods: Fifty intact human third molars were divided into enamel (E) (n = 20) and dentin (D) (n = 30) groups. Each tooth was sectioned in four quadrants with a diamond saw to achieve 200 tooth surfaces and expose flat enamel and dentin surfaces. Then, E and D groups were divided into total-etch (T) and self-etch (S) subgroups with dentin group further divided into 2 drying modes: drying (DD) and over drying (DOD). Each subgroup (n = 10x¼teeth) was surface- treated with 4 different universal adhesives: Tetric N-Bond Universal (IvoclarVivadent) (TRC), Ad- per Single Bond Plus (3M ESPE) (ADP), OptiBond Solo Plus (Kerr) (OPB) and Prime & Bond NT (Dentsply) (PB). A transparent custom mould (h: 3 mm, diameter: 8 mm with a central hollow of 1 mm) was used to pack a composite. Composite was light-polymerized and MSBS testing was made on a universal testing machine (cross-head speed: 1 mm/s) followed by fractographic analysis. The data were statistically analyzed (two-way ANOVA, Tukey’s, p = 0.05). Results: In DOD group, TRC exhibited the highest MSBS values, while OPB showed the lowest (p < 0.05). In DD group TRC and ADP provided higher bond strength values when compared with OPB and PB subgroups (p < 0.05). When gently-dried and over-dried dentin groups were compared, only TRC showed no significant differences (p > 0.05). Conclusions: In over dried dentin group, TRC exhibited the highest bond strength. Drying both enamel and dentin substrates at once would not compromise the bond strength values with the use of the new tested universal adhesive.

Oral Presentation No. 16 Fracture surface analysis of PM CP titanium after ceramic debonding

Josko Viskic, Amir Catic, Zdravko Schauperl, Martin Balog, Peter Krizik, Ketij Mehulic University of Zagreb, School of Dental Medicine, Croatia

Purpose: Bonding of dental ceramics to commercially pure titanium (CP Ti) has always been a challenge. Thick oxide layer formation on the surface of titanium weakens the bond and leads to predominantly adhesive fractures between CP Ti and veneering ceramics. CP Ti manufactured by powder metallurgy (PM) processes has not yet been used in prosthodontics as a method for metal substructure manufacturing. The aim of this study is to evaluate the fracture mode between CP Ti manufactured by PM and veneering ceramics. Materials and Methods: 120 samples of CP Ti manufactured by PM were divided into 5 groups according to surface modifications: 1. untreated; 2. sandblasted (Al2O3); 3. with applied bonding agent; 4. sandblasted (Al2O3) and with applied bonding agent; 5. etched with hydrochloric acid. All samples were veneered using low fusing dental ceramics. Each group was divided into 3 subgroups of 8 samples according to veneering ceramics. Surface of the samples was evaluated for fracture mode by XRD analysis before veneering and after debonding. Results: XRD analysis of samples analysed before veneering showed pure α-Ti. After debonding only two of the fifteen groups showed traces of ceramics on the surface (cohesive fracture) and the rest showed only presence of α-Ti, β-Ti and different types of titanium oxides (adhesive fracture). Conclusions: Fracture mode analysis of veneered CP Ti manufactured by PM shows similar results as conventionally manufactured CP Ti, suggesting the PM Ti material can potentially be used in crown manufacturing. However, further studies involving other methods of fracture mode analysis are necessary to draw definite conclusions.

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Oral Presentation No. 17 Adhesion between composite and titanium with different metal primers

Ayşe Yalnız, Yüksel Yazıcıoğlu, Ender Kazazoğlu Yeditepe University, Dental School, Turkey

Presentation was cancelled.

Oral Presentation No. 18 Corrosion behaviour of dental ceramics

Lenka Vavřičková1, Anna Krejčová2 1Charles University in Prague, Faculty of Medicine in Hradec Kralove, Department of Dentistry 2University of Pardubice, Faculty of Chemical Technology, Department of Environmental and Chemical Engineering, Czech Republic

Purpose: Although dental ceramic materials are considered bioinert, none of these materials is non-corroding. First aim of this study was to determine the level of corrosion of selected ceramic materials. Second aim of the study was to determine the level of corrosion of ceramic material (most corrosive in the part one) In-Ceram® Spinell in commonly used beverages. Materials and Methods: 11 types of ceramic materials from all groups of dental ceramic materials have been chosen. The composition of ceramic materials was qualitatively evaluated by X-ray spectrometry using the wave disperse XRF spectrometer Spectroscan MAKV-GV (Spectron NPO, Russia). For evaluation of a corrosive behaviour, leaching under extreme conditions was carried out. Hydrochloric acid was used (3 ml 0.1 mol.l-1 HCl, 120 hours, 37 ± 1 °C), then extracts were filled up to 10 ml and analysed by mean of inductively coupled plasma optical emission spectrometry (ICP-OES, Integra XL2, Australia). Then In-Ceram® Spinell was immersed using following leaching agents: Ice Tea Peach (Lidl Stiftung & Co. KG, DEU; pH 2.99), Freeway Cola (Lidl Stiftung & Co. KG, DEU; pH 2.42), red wine Cabernet Sauvignon (Wine Cellars Peter Metres KG; pH 3.59), white wine Cabernet Sauvignon (Israel; pH 3.23), juice 100% orange (Relax Ltd., NZL; pH 3.76), mouth wash Colgate Plax Whitening (Colgate-Palmolive, SUI; pH 8.04), 0.9% NaCl (pH 5.35), 0.5% acetic acid (pH 2.56), 2% citric acid (pH 1.98), 0.1M HCl (pH 1.54), redistilled water (pH 5.70). Samples of the mentioned material were immersed at 37 °C during seven days. The change of sample masses, a surface structure and a colour were studied. Released elements were determined using again ICP-OES. Results: In extracts, measurable amounts of elements were found: sodium (0.065 – 1.1), magnesium (0.012 – 0.15), iron (0.32 – 1.2), manganese (0.0042 – 0.096), zinc (0.014 – 2.7), silicon (up to 0.63), aluminium (up to 0.97), yttrium (up to 0.21) and titanium (up to 2.6, all in mg.l-1). Zirconium and gold were found in leachates. The loss up to 2% of the origin mass was found for tests of In-Ceram® Spinell with citric, hydrochloric and acetic acids, Ice Tea Peach, juice and white wine. Samples treated in Freeway Cola and red wine came under colour changes irremovable by water rinsing. ICP-OES analysis of In-Ceram® Spinell demostrated the increase in concentration of calcium, magnesium, aluminium, yttrium, silica and other elements. Conclusions: The presence of released ions in the extracts was also documentated in ceramic materials. The corrosive behaviour of In-Ceram® Spinell was monitored in the presence of currently used beverages. The colour change and the loss of the mass can have important clinical impact. None of the known dental materials can preserve absolute resistance against all corrosion forms. Supported by the programme PRVOUK P28.

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Oral Presentation No. 19 The era of monolithic translucent zirconia: Two case reports

Despoina Chatzistavrianou, Shakeel Shahdad, Philip Taylor Barts Health NHS Trust, The Royal London Dental Hospital, United Kingdom

Purpose: Yttria-stabilised zirconia polycrystalline (Y-TZP) ceramics were introduced as a biomaterial in restorative dentistry to eliminate the incidence of bulk fracture in all ceramic restorations. Although, Y-TZP ceramics exhibit high flexural strength and fracture toughness, chipping of the veneering material, reduced translucency of the core and heavy tooth reduction limit their use. Recently, monolithic translucent zirconia restorations were introduced in an effort to eliminate chipping of the veneering material and minimise occlusal and axial tooth reduction. Less wear to the antagonist tooth and improved aesthetic outcomes compared to traditional zirconia cores were demonstrated in in-vitro studies. Furthermore, these are cost-effective restorations since ceramic veneering is not required. The aim of this study was to present two case reports demonstrating rehabilitation with monolithic translucent zirconia restorations and discuss the clinical challenges of this treatment modality. Materials and Methods: Case 1: A 25-year-old female patient with history of trauma to her maxillary anterior teeth received implant supported crowns in the lateral incisors and monolithic translucent zirconia crowns in the central incisors allowing minimal tooth reduction. Case 2: A 25-year-old female patient with amelogenesis imperfecta received monolithic translucent zirconia onlays in the maxillary and mandibular posterior teeth to increase the occlusal vertical dimension and facilitate full mouth reconstruction. Results: Patients were satisfied with the functional and aesthetic outcome at the end of the treatment and no complications were noticed at the 3 month review appointment. Conclusions: Although, the use of these materials is increasing, further clinical trials are necessary to confirm its clinical application.

Oral Presentation No. 20 Effect of surface treatments on bond strength of CAD-on technique

Tuba Yilmaz, Necla Demir, A. Nilgün Öztürk Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: The aim of this study was to investigate the effect of different surface treatments (sandblasting, Er:YAG and Femtosec lasers) on shear bond strength (SBS) of CAD-on technique. Materials and Methods: Forty Y-TZP zirconia plates (IPS e.max ZirCAD, Ivoclar Vivadent) were cut, sintered (12.4 × 11.4 × 3 mm) and divided into four groups according to the surface treatments:

50 μm Al2O3 sandblasting (group S), Er:YAG laser irradiated (group E), Femtosec laser irradiated (group F) and no surface treatment as a control (group C). Also forty cylindrical (5 mm – diameter, 2 mm – height) lithium disilicate (IPS e.max CAD) veneer ceramics were cut and fused to all zirconia cores by a glass-fusion ceramic and crystallized according to CAD-on technique. Specimens were subjected to shear force using a universal testing machine. Load was applied at a crosshead speed of 0.5 mm/min until failure. Mean SBS (MPa) were analyzed with one-way ANOVA (p < 0.05). The failed specimens were examined under a stereomicroscope at x20 to classify the mode of failure. Results: The highest SBS was observed in group FS (36 ± 3.31 Mpa), followed by group SB (33.03 ± 5.05 MPa) and group C (32.52 ± 10.15 MPa). The lowest SBS was observed in group ER (31.02 ± 4.96 Mpa). But no significant differences were found between the control and surface treated groups (P = 0.377). All the specimens showed mixed type (adhesive and cohesive) of failure. Conclusions: Femtosec laser application has increased the bond strength between zirconia-veneer specimens. However, novel CAD-on technique with no surface treatment also showed high bond strength. Thus, this technique could increase ceramic bonding to zirconia without additional surface treatments. 38 39th Annual Conference of the European Prosthodontic Association

Oral Presentation No. 21 Shading impact on the bond of Y-TZP to resin cement

Farhad Tabatabaian, Minoo Mahshid, Naeem Berijani, Seyed Jalil Sadr University of Medical Sciences, Dental School of Shahid Beheshti, Department of Prosthodontics, Tehran, Iran

Purpose: Shading Y-TZP ceramics affects the mechanical properties, however effect of shading on the bond strength of zirconia to resin cement is lacking in the literature. This investigation evaluated the effect of dipping a zirconia ceramic in different colour liquids on the micro-tensile bond strength of zirconia ceramic to a resin cement. Materials and Methods: This in vitro study was conducted on 100 microbar specimens divided into 5 groups of B2, C1, D4, A3 and Uncolored (control). To prepare the microbars, 20 white zirconia ceramic blocks, measuring 5 × 11 × 11 mm, were dipped in each of shades A3, B2, C1, or D4 colour liquids for 10 seconds (5 blocks each colour liquids) and 5 blocks remained uncoloured for the control. Composite blocks of similar dimensions were fabricated and bonded to zirconia ceramic blocks using Panavia F 2.0 resin cement. Zirconia-cement-composite blocks were sectioned into microbars measuring 1 ×1 ×10 mm. The micro-tensile bond strength of microbars was measured by testing machine. Data were analyzed using one-way ANOVA and Tukey’s test. All tests were carried out at the value of significance 0.05. Results: Statistically significant differences were found among the groups in micro-tensile bond strength values (p < 0.001). The group D4 was the highest with 39.16 ± 6.52 MPa. Conclusions: Shading affected the micro-tensile bond strength of zirconia ceramic to Panavia F 2.0 resin cement; however, a similar pattern of change was not shown among the different colour liquids.

Oral Presentation No. 22 Topographical properties of zirconium-dioxide: Effect of polishers with different surface- coatings

Mutlu Özcan1, Nadin Al-Haj Husain2 1University of Zürich, Head of Dental Materials Unit, Switzerland 2Dental Practitioner, Zürich, Switzerland

Purpose: Improper surface finishing of fixed dental prosthesis made of monolithic zirconia (MZ) may cause opposing enamel wear. This study investigates the surface topography parameters and wettability of MZ using polishers with different coatings. Materials and Methods: MZ specimens (N = 50, n = 10 per group) (Katana Zirconia HT) (12 × 12 × 1.8 mm3) were polished and randomly allocated to 5 groups, namely BG: Silicon carbide polishers (Brownie, Greenie, Super Greenie); CG: Diamond impregnated (Ceragloss); EV: Synthetically bonded grinder interspersed with diamond (EVE-Kit); SL: Urethane coated paper with aluminium oxide grits (Soflex-Kit) and DB: Diamond bur (8 µm, FG9205/6). After roughening (Grinding Bur- GB) (220 µm grit, 10 s, 160,000 rpm) and baseline measuring, each polishing step was performed for 10 s (750 g, 5,000–30,000 rpm) according to manufacturer`s instructions. Changes were evaluated considering: a) Weight (digital scale); b) Volume loss (digital microscope); c) Vertical height loss (digital microscope); d) Surface roughness (profilometer); and e) Surface wettability (goni- ometer, water). Data for each parameter were statistically analyzed (one-way ANOVA, Scheffé, Wilcoxon) (alpha = 0.05). Results: The material loss after polishing compared to baseline ranged between -3 ± 0.1 × 10-4 – -296 ± 8 × 10-4 g in ascending order as follows: Sla < CGa < BGa < DBb < EVc, volume loss between -0.158 ± 0.03 × 10-6 – 0.245 ± 0.07 × 10-6 mm3 (Sla < BGa < CGa,b < DBb < EVc), vertical height loss between -18.91 ± 3.52 – 55.19 ± 6.26 µm (Sla < BGa < CGa,b < DBb < EVc), surface

39 39th Annual Conference of the European Prosthodontic Association roughness between -0.143 ± 0.015 – 0.855 ± 0.419 µm (DBa < BGa < Sla < CGa < EVb) and contact angle between -3.93° ± 0.79° – 2.79° ± 3.14° (BGa < DBa < Sla < CGa < EVa). Conclusions: All the polishers performed similar when Ra values are considered. After 40 s of polishing, SL, BG and CG performed similar, producing the least material loss of MZ, while EV could not be suggested for polishing.

Oral Presentation No. 23 Professional smile designing: Going digital

Mohannad Kiswani, Iman Nazzal Amman, Jordan

Purpose: 1. To emphasize the importance of smile designing in everyday clinical practice. 2. To show the history of smile designing in dental practice starting from manual and ending to virtual digital ways. 3. To be able to identify the basic requirements needed to start smile designing for a case. 4. To be able to compare and choose between different smile designing systems available in the market based on scientific selection. 5. To show the method of presenting a case for patients after performing smile designing digitally. Materials and Methods: Many digital programs and protocols have been introduced to the dental market the last few years. Some of them focused on the style of imaging and producing a virtual simulation to the patient, helping him in imagining how his smile going to look like after the planned esthetic dental work. 8 programs were collected, and used to design patients smiles, then they were analyzed according to preclassified criteria and given scores. Results: No ideal software for smile designing is yet available in the market, however, dentist can identify the closest software that covers the needs of his practice and choose the highest score. Conclusions: Many digital programs and protocols have been introduced to the dental market the last few years. Some of them focused on the style of imaging and producing a virtual simulation to the patient, helping him in imagining how his smile going to look like after the planned esthetic dental work. Some soft wares need minor improvements to get closer to the ideal characteristics required from a designing software, others need dramatic changes to be able to meet the minimum needs of a dentist.

Oral Presentation No. 24 Factors inflencing the dimensional accuracy of 3D-printed full coverage dental restorations using stereolithography technology

Nawal Alharbi, Reham Osman, Daniel Wismeijer University of Amsterdam and Vrije Universiteit, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands

Purpose: With the advancement in CAD/CAM technology, additive manufacturing (AM) or 3D-printing is emerging in the dental fild and is promising in manufacturing of dental restorations. The aim of this study was to evaluate the effect of the build orientation (the angle of the support) and dimensions of the support (thick vs. thin support) on the dimensional accuracy of 3D-printed full coverage dental restorations. Materials and Methods: A full dental crown was digitally designed and 3D-printed using stereolithography (SLA-AM) technology. Nine angles were used for the building orientation as follows: 90°, 120°, 135°, 150°, 180°, 210°, 225°, 240° and 270°. In each build orientation, the crown was printed using a narrow and a wide type of support. The specimens were digitally scanned using a high-resolution optical surface scanner. The dimensional accuracy was evaluated using digital sub-

40 39th Annual Conference of the European Prosthodontic Association traction technique. The 3D-digital files, exported in standard triangulation language (STL) format, of the scanned printed crowns (test model) were superimposed with the STL fies of the designed crown (reference model) using Geomagic® studio; 2014. The average deviation between the two models and the root mean square estimate values (RMSE) were then evaluated. Additionally, the deviation pattern on colour map was further assessed. Results: The build angle and different dimensions of the support structure are suggested to inflence the dimensional accuracy of 3D-printed restorations. The lowest average deviation was found with the build angle of 120° for both thin and thick type of support (0.019 and 0.021 mm respectively). Further, the RMSE value recorded for thin type of support (0.029 mm) was lower compared to the thick type (0.031 mm), indicating a more accurate fit between the test and reference models. Conclusions: Within the limitations of this study, the preferred build orientation using SLA printing technology is 120° combined with the thin type of support. The selected build angle offers the highest accuracy of the printed restorations. It also offers the least needed surface support area which decreases the time needed for fiishing and polishing

Oral Presentation No. 25 Some anatomical considerations for implant-supported restorations in edentulous patients

Yoav Pietrokovski, Abraham Zini, Jaime Pietrokovski Hebrew University hadassah Jerusalem, Faculty of Dentistry, Department of Prosthodontics, Israel Hebrew University Jerusalem, Faculty of Dentistry, Department of Community Dentistry, Israel

Purpose: After the loss of natural teeth, the alveolar process and part of the basal bone remodels, resulting in edentulous residual jaws. The resulting residual arches provide the vital foundation on which should be placed the denture bases and the artificial teeth into their selected positions. The residual arches also furnish the foundation of osseo-integrated implants for the planned restorations. The purpose of this study was to learn some characteristics of the edentulous arches, the relations between occluding jaws and their clinical importance. Materials and Methods: One hundred and six edentulous subjects which rendered 212 casts, mounted in centric relation, were examined and measured. There is a large disparity in sizes and shapes of the edentulous arches and varied spatial interarch characteristics. Results: The space conformed between the recommended teeth-gingivae wax-up scaffold and the residual tissues surfaces, provides a prosthetic space to be properly occupied by the bone augmentation material, implant abutments, crowns, fixed bridges and/or denture bases according to the individual requirements and possibilities. Conclusions: The precept of beneficial effect of axial close forces to the supporting bone is widely accepted in orthopaedic implant surgery and in dental implantology. However nowadays, in implant dentistry, there is a disagreement on this axiom and successful oblique and distant osseo-integrated implants are reported in the current literature. Regardless of these different considerations, it is important to know, before the insertion of osseo-integrated implants, the individual anatomy and the spatial relations of the residual ridges between occluding edentulous jaws in each patient. This will contribute for a more cosmetic and functional rehabilitation.

Oral Presentation No. 26 Multidisciplinary intervention for prosthetic rehabilitation

Arman Barfeie, Adrian Watts, Jeremy Rees Cardiff University, School of Dentistry, Heath Park, United Kingdom

Presentation was cancelled.

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Oral Presentation No. 27 Alternative attachment incorporation methods in implant-supported overdentures with non- splinted abutments

Cumhur Sipahi Gulhane Military Medical Academy, Ankara, Turkey

Purpose: The rehabilitation of completely edentulous mandibles with implant-supported overdentures (ISOs) is now a popular treatment modality with world-wide acceptance. Two types of overdenture attachments are essentially used for the retention of ISOs: splinted and unsplinted attachments. Splinted attachments may be either rigid (U-type tissue bar) or non-rigid (Dolder bar or Hader bar). Non-splinted attachments may also be either rigid (locators or telescopic retainers) or non-rigid (ball/stud attachments). The connection between the matrix and the denture can be achieved by indirect or direct method. The direct method for integrating a non-splinted attachment (ball or locator) intraorally is relatively simple, economic, requires minimal chair time, does not ne- cessitate additional laboratory procedures or component parts, and can be achieved at prosthesis insertion appointment. The most frequently seen complications in the direct incorporation method are metal housing debonding, incorrect orientation of attachment components and entrapment of autopolymerizing acrylic resin within the retainer(s). Materials and Methods: Presentation of alternative direct attachment incorporation methods in order to prevent or minimize metal housing debonding, attachment malpositioning and acrylic resin entrapment within attachment undercuts. Results: Accurate incorporation of the attachment into the overdenture is crucial for effective function, patient comfort and tissue preservation. Conclusions: Currently, not any evidence based data exist in the literature about the clinical su- periority of using splinted versus unsplinted attachments in ISOs. However, the high treatment costs, technique sensitivity and prosthetic space requirements for splinted attachments make the unsplinted attachments more popular choices for both patients and clinicians.

Oral Presentation No. 28 Evaluation of immeditate loaded implants in single tooth missing zone

Pınar Yıldız, Mustafa Zortuk, Mehmet Dinçel Erciyes University, Faculty of Dentistry, Melikgazi, Kayseri, Turkey

Purpose: The aim of this study was evaluation of the immediate loading of platform switching implants at single tooth missing in the aesthetic zone of maxilla clinically and radiographically. Materials and Methods: Thirty three (23 female, 10 male) patients with a single missing tooth on the maxillary anterior region participated in this study. Immediate loading protocol with temporary abutments was applied to 18 of these patients without function. Two of these implants were lost because of early dental implant failure. Late loading protocol was applied to the other 15 patients. Pocket depth, bleeding index, gingival index, plaque index and keratinized gingival width were measured during the final loading session and after 1 month, 3 months, 6 months and 12 months of loading. The periapical radiographs of the patients were taken in the session of loading, after 1 month, 3 months, 6 months and 12 months of loading. Marginal bone losses were measured on the radiographs. Results: As a result of one-year follow-up, success rates were 88.88% for immediate loading group and 100% for delayed loading group. There was not any statistically significant difference of marginal bone resorption between groups. The probing depth showed statistical difference between the groups at first month and bleeding index had significant difference between the groups at third and sixth month’s sessions. There was not any significant difference between the groups for other clinical parameters.

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Conclusions: According to the results of this study, with the help of appropriate patient selection and good practices, there would be no significant clinical and radiographic difference between immediate loading and delayed loading protocols.

Oral Presentation No. 29 Fracture resistance of oval and circular dowels used in oval root canals

Halil İbrahim Kılınç, Tuğrul Aslan, Kerem Kılıç, Özgür Er, Emir Esim, Şahin Yıldırım Erciyes University, Faculty of Dentistry, Department of Prosthodontics, Kayseri, Turkey Trakya University, Faculty of Dentistry, Edirne, Turkey Erciyes University, Faculty of Engineering, Kayseri, Turkey

Purpose: To evaluate different dowel morphologies and different dowel placement lengths on the fracture resistance of teeth with oval canal morphology treated endodontically and restored with crowns. Materials and Methods: Extracted mandibular premolars with similar dimensions were decoro- nated. After the root canal treatment, the teeth were mounted on acrylic blocks. Samples were randomly divided into four groups of 10 samples each. In groups C-10 and C-5, 10 mm and 5 mm long circular dowel space was achieved with #0.5 and #2 coded manufacturer’s drills, respectively. In groups O-10 and O-5, respectively, 10 mm and 5 mm long oval dowel space was achieved ultrasonically with the manufacturer’s medium gritted tips. Dowels were cemented using resin cement and the self-adhesive technique. All specimens were restored with composite cores and prepared at a height of 6 mm (including 1 mm ferrule) and a convergence angle of approximately 5° in total. Then, all teeth were restored with metallic crowns. After thermocycling, all specimens underwent fracture resistance testing. Data were analyzed using the two-way ANOVA test (α = 0.05). Results: Oval dowels and placement of dowels at 10 mm depth showed higher fracture resistance than circular dowels and placement of dowels at 5 mm depth (p < .001). Conclusions: Increased dowel length and use of oval dowels enhanced the fracture strength of teeth with oval canal morphology.

Oral Presentation No. 30 Stress distribution in cantilevered fixed partial denture with different C/I ratio

Hamiyet Güngör, İlgi Baran Kirikkale University, Turkey

Purpose: The prosthetic treatment procedure with dental implants of posterior edentulous maxilla is difficult because of maxillary sinus and bone density. Cantilever fixed partial denture can be the treatment option which doesn’t take long time and need extra treatment cost. In addition it is very important to evaluate the effect of crown/implant ratio in resorbed maxilla for getting successful treatment result. The aim of this study was to evaluate the stress distribution in cantilevered fixed partial denture with different crown/implant ratio. Materials and Methods: A maxillary jaw modelled in D3 bone density with 3D finite element method. A 4.1 mm in diameter and 10 mm in height ITI implant was modelled with two unit distal cantilevered fixed partial dentures. Cr-Co metal substructure and feldspathic porcelain were used for the restoration. The mesiodistal dimension of cantilever was 7 mm. 3 different crown/implant ratios (1/1; 1.5/1; 2/1) were used. 300 N oblique loads were applied for each crown. Data were evaluated in cortical bone, implant and metal substructure. Results: Minimum principle stresses were localized buccal, distal and palatinal side of the implant neck in cortical bone. The min. principle stress was -106.8 MPa for the 1/1 crown/implant ratio.

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When the crown/implant ratio increased, the min. principle stress increased % 17.5 and % 32.3 respectively. While increased stress was seen in implant too, metal substructure didn’t show this kind of characteristic property. Conclusions: The effect of increased crown/implant ratio is important for both the cortical bone and implant.

Oral Presentation No. 31 Prevalence and risk variables analysis for peri-implant disease

K. C. (Basnyat) Smriti1, Zhang Xiao2 1Dhulikhel Hospital, Kathmandu University, Nepal 2Zhengzhou University, China

Purpose: The aim of this study was to assess the prevalence of peri-implant mucositis and peri- implantitis and establish the association of different variables associated with it, also to find out the awareness level, practice of oral hygiene and maintenance among implant patients. Materials and Methods: Patients visiting the Dental Outpatient Department of Zhengzhou Universi- ty, China were selected for the study. The examination was conducted using basic diagnostic tools (Mouth mirror, HU-FRIEDY periodontal probe). They were categorized into those with healthy implants and those who had developed peri-implant mucositis or peri-implantitis using the formulated indicators. The statistical association of different variables with peri-implant disease was calculated using Chi-square test and Fisher’s test using SPSS version 16. Results: Out of 63 dental implant patients examined, 41 had healthy implant, 20 patients suffered from peri-implant mucositis and only 2 of them had incidence of peri-implantitis.The statistical analysis showed bleeding on probing, clinical attachment level, plaque index and gingival index are statistically associated with peri-implant disease. The other variables like age, gender, time of follow-up, brushing technique, smoking habit etc. did not show statistical association with peri- implant disease. Conclusions: The overall oral hygiene, maintenance and care practiced by implant patients were good and there awareness level regarding oral hygiene was also high. This is largely due to follow up instructions given to the patients to improve the awareness level.

Oral Presentation No. 32 Replacing first premolar and first molar with cantilever bridge: A clinical study

S. M. R. Sazvar, H. Ansari, M. Mobayeni, A. Mazaheri Islamic Azad University, Dental Brach, Tehran, Iran

Purpose: Evaluation of cantilever bridge for replacing lower first premolar and first molar using second premolar and second molar as abutment teeth. Materials and Methods: In this experimental study we selected 23 patients with missing lower first premolar and first molar on the base of a specific protocol. All of them understood this treatment and other alternative methods and signed the informed consent. We provided 4 units cantilever porcelain fused to metal bridge with base metal alloys using second premolar and second molar then missing teeth were replaced. All patients were controlled with clinical examinations and radiography during 5 years with no data loss. Statistical analyses of Chi-square showed: p = 1 and regarding the p > 0.05, it means the test is not significant or there were not any destructive symptoms (Alpha = 0.05). Results: This research stated 100% of volunteers asymptomatic. Regarding Chi-square analysis test during 5 years follow up p = 1 (Alpha = 0.05) although it is not significant but it states all of 23

44 39th Annual Conference of the European Prosthodontic Association treated persons had no failures. Conclusions: In the present research we found the treatment in all patients have been successful during the period. These findings can be related to the specific protocol for selecting cases and/or the period is not so long term. It seems our method can be a reliable treatment and the excellent findings may be related to our specific case selection but we suggest more long-term studies.

Oral Presentation No. 33 Influence of different protocols for cement removal during cementation on implants

Larisa Jercan Bucharest, Romania

Purpose: Purpose of this study was to evaluate the influence of different protocols for resin cement removal during cementation in various depth gingival sulci on an experimental model. Materials and Methods: Various depths of gingival sulcus were built around implant-supported porcelain fused to metal crown. The subgingival location of the margin of each implant was measured with a periodontal probe. The crown was repeatedly luted on the abutment, and the artifical gingiva was removed after thoroughly cleaning the excess cement in order to observe if debris remains in the sulcus or on the implant abutment. The four methods used were with rubber dam, with PTFE tape and silicon index, with dental floss and by measuring the volume of cement to be used. Results: Cementing on implant abutments proved to be a technique sensitive procedure. Conclusions: In greater depth sulcus the unremoved cement can and will lead to complications such as periimplantitis therefore this topic is of high interest for any practitioner.

Oral Presentation No. 34 Pain and dysfunction after changing the VDO – digital analysis and occlusal hygiene

Hans van Pelt1, Marcel Linssen2, Rob Groot2, Michiel Lieshout2 1University Groningen, Dept. Oral Function, The Netherlands 2Dental Practitioner, Rotterdam, The Netherlands

Purpose: The aim of this presentation is to demonstrate the use of digital analysis of the occlusion in a patient with heavy pain and dysfunction complaints after changing the VDO. Materials and Methods: Clinical case: A 39-year-old woman was referred to us after treating generalized tooth surface loss three month before. She lost weight due to heavy toothache and muscle pain. One molar was treated endodontically without relieve of the pain. Intra-orally there seems to be no proper ICP and no contact of the canines. Increase of the VDO is estimated to be 3 mm. Palpation of the muscles is painful especially on the left side in the temporal region. Results: With a t-scan (Tekscan) the contacts between upper and lower teeth were digitally analysed. The scans were necessary because the patient was avoiding contact due to pain and therefore not able to reproduce the bite. There was no contact on the right side at all. 60% of the total bite force was concentrated on the second left molar. The occlusion was equilibrated with smooth diamond burs and polishing cups guided by new scans after each correction. Finally the two canines were built up to achieve canine protection and disclusion of the posterior teeth in protrusive and lateral movements. Recall after one week showed almost total relieve of the pain and balanced occlusion with canine protection. Conclusions: Digital analysis of the occlusion proves to be a helpful instrument to judge the force distribution in occlusion.

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Oral Presentation No. 35 Interdisciplinary creation of bone and teeth after severe trauma

Rob Groot, Hans van Pelt, Manfred Leunisse, Dick Barendregt, Marcel Linssen, Michiel van Lieshout PRO Rotterdam, The Netherlands

Purpose: The aim of this presentation is to show a solution for non-surgical bone augmentation in young patients with missing teeth after severe dental trauma, combined with autotransplantation, implantology and prosthodontics. Materials and Methods: This case study shows us that it is possible to acquire dense alveolar bone by moving teeth through the (remaining of) the processus alveolaris. It also shows us the possibility of autotransplantation of endodontic treated elements. Results: The transplanted elements grow along with the developing of the face and skull. Autotrans- plantation appears to be a good expansion of our treatment possibilities for young adults who otherwise would have to wait for fixed prosthodontics on implants until they have stopped growing. Conclusions: It appears that the PDL is capable of creating a beautiful, thick process by the ortho- dontical moving of teeth. We “just” have to understand the biology of the PDL. Autotransplantation of a vital or endodontically treated tooth is a very valuable alternative for implants and usable for young patients who do not have stopped growing yet. It is a requisite to act as an interdisciplinary team of orthodontist, endodontist, periodontist and prosthodontist to develop a procedure of getting predictable results in case we create new alveolar bone and gingiva by means of selective orthodontic movement of teeth and perform autotransplantations.

Oral Presentation No. 36 Laser application in modern dental medicine

Doriana Agop-Forna University of Medicine and Pharmacy Gr. T. Popa, Dento-alveolar Surgery, Iasi, Romania

Purpose: Laser technique facilitates the practical execution of interventions on both hard tissues (regularization, slicing, and apicoectomy) and on soft tissue (frenectomy, gingivectomy, incision, curettage, ablation of cysts, granulomas). Materials and Methods: For a number of 60 cases we used both the Biolase laser system, and KaVo Key 3 laser, noting differences compared to the classical surgical technique, on the basis of duration, pain, bleeding, sterilization, and by comparing two laser systems. Results: For the Biolase system we obtained decreased time of execution, higher accuracy, and higher sterilization than for KaVo system. Conclusions: Rigor and difficulty to finish the maneuvers were by 2% higher for KaVo than for Biolase system. Acknowledgement POSDRU/160/2.1/S/139881

Oral Presentation No. 37 Implant treatment in a patient who is under methotrexate medication: A case report

Polykarpos Papanagiotou, Stavros Pelekanos University of Athens, Greece

Purpose: Presentation of case report: a 58-year-old male patient presented the request to remove his full arch maxillary prosthesis and restore it with implants.

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Materials and Methods: The patient takes methotrexate every week to treat psoriasis. Psoriasis is evident on his hands and legs. Besides psoriasis the patient has no other medical condition that can be contradictive to implants. This case report will discuss the treatment modality that was followed; the surgical difficulties that appeared during implant placement and the adverse effects caused by methotrexate intake. The adverse effect was painful, had a negative impact on the healing progress and thus the patient´s trust was unsettled. Results: The case report presented the conclusions made after the treatment and made sugges- tions for a therapeutical scheme that can minimize these adverse effects on patients who wish to have implants and take methotrexate. Conclusions: Up to date, there are no sufficient data to correlate implant placement with patients under methotrexate medication.

Oral Presentation No. 38 Bruxism and tinnitus

Radmila Sedláčková Dental practitioner, Náchod, Czech Republic

Purpose: Bruxism is recognized as an activity by which stress is reduced. When bruxism coincides with a disharmony between the arrangement of the teeth and with an inclination of both the occlusal plane and the condylar path, the result is not only the destruction of dental tissue but also the change of the position of the condyle in the glenoid fossa. When the adaptation of the patient is exhausted, then tinnitus – a personal perception of a sound within the ear when no external sound is present – may be the result due to the anatomical proximity of the medial pterygoid muscle, which is always active during bruxing, to the synergic muscles tensores tympani and veli palatini. Materials and Methods: The author reports the case of a 61-year-old bruxing patient with tinnitus, who is gradually losing hard dental tissue. The patient underwent a systematic clinical and instru- mental analysis according to the Viennese school. On this basis the patient received a mandibular splint as a long-term provisional. Results: After 3 months of the wearing of the splint, tinnitus disappeared. The positive result was then fixed in provisoria made out of PMM according to the wax-up technique with the concept of se- quential guidance. The metric data gained by axiography were applied in the individually adjusted articulator and the casts were mounted on the individual hinge axis. Conclusions: Due to the stabilisation of occlusion, tinnitus faded away. Although the bruxism has not ceased, further destruction of dental tissue could be averted.

Oral Presentation No. 39 Cleft patients – solutions of dental defects

Wanda Urbanová1, Magdalena Koťová1, Marie Bartoňová2 1Charles University in Prague, 3rd Faculty of Medicine, Dental Clinic, Department of Orthodontics and Cleft Anomalies, Faculty Hospital of Kralovske Vinohrady, Czech Republic 2Dental clinic J&B medic, Prague, Czech Republic

Purpose: The aim of the study was to estimate the best solution for missing teeth in upper frontal region in patients with orofacial cleft. Cleft lip and palate is associated with both quantitative and qualitative deficiency of the osseous and soft tissues. In more than half of cleft patients numerical defect of the dentition is present, predominantly missing tooth is a lateral incisor on the cleft side. Matherials and Methods: The group of young adults with cleft lip and palate treated at the Centre for treatment of congenital anomalies of the face and neck at FNKV was investigated and different

47 39th Annual Conference of the European Prosthodontic Association treatment options were detected. Results: The decision regarding prosthetic solution in patients with cleft lip and palate has to be based on interdisciplinary cooperation between prosthodontist, orthodontist, implantologist and plastic surgeon. The biological factor of the teeth, extent of the defect and condition of the soft tissues, quantity and quality of the bone in the cleft alveolar ridge, the shape and relationship of dental arches and finally the patient’s cooperation have to be considered. There are several possible prosthetic solutions in the atypical situations of the cleft jaws: dental implant, specially adjusted fixed prosthetic bridge or removable denture serving also as the obturator. Conclusions: Prosthetic reconstruction of dental defects in cleft patients has its own specifics because of atypical anatomical situation and the low age of the patients. Individualized treatment plan and a detailed planning of the form and range of the prosthetics are necessary.

Oral Presentation No. 40 No time limit for using autotransplants

Dick Barendregt, M. Linssen, E. Eggink, M. Leunisse PRO Rotterdam, The Netherlands

Purpose: Autotransplants are a widely used treatment option in the Scandinavian countries. The primary indication is in young adults teeth where open apices are used with good success rates (on average 90 to 95% after 10 years). In our referral practice in Rotterdam the purpose was to investigate if a comparable success rate could be accomplished with fully developed teeth. Material and Methods: Up to April 1, 2015, 125 fully developed teeth were transplanted to various receptor sites. The treatment modality prescribed that if possible the endodontic treatment was done 4–6 weeks before transplantation. No prophylactic antibiotics were used with the transplantation procedure. Results: Results show that in a follow-up period of 12 to 126 months the success rate added up to 95% and the survival rate 98%. In 2% the external root resorption was observed and in total in 23% of the cases antibiotics were prescribed after the transplantation procedure. Conclusions: In conclusion transplantation of fully developed teeth is as successful as for teeth with open apices. Therefore this treatment modality is a viable option in daily practice and preferable over dental implants. With use of fully developed teeth age is no restriction.

Oral Presentation No. 41 Autotransplantation in young patients after dental trauma in anterior teeth in the upper jaw: Review of a guideline

Pieke Wagemakers, Hans van Pelt, Dick Barendregt en Marlieke University of Groningen, University Medical Centre Groningen, Dental School, Department of Fixed and Removable Prosthodontics, The Netherlands

Purpose: The aim of this research was to determine if actual treatment planning of autotransplantation in a multidisciplinary dental practice (Proclin, Rotterdam) is corresponding to the existing guideline for autotransplantation. Materials and Methods: Through a literature review, the existing guideline for autotransplantation is examined on its evidence. Subsequently a checklist is developed to analyze whether the guideline is applied consistently. Results: Many articles were found describing the treatment planning of autotransplantation and substantiate the guideline. However, lack of consensus concerning several details exists. For the clinical research 28 autotransplantations within 24 patients were included. At the time of the surgical procedure the mean age was 12.2 year (r = 10.25–16.83 year) and the follow-up period was 48 39th Annual Conference of the European Prosthodontic Association

34 months (r = 11–94 months). A survival rate of 96.4% was found, due to loss of 1 transplanted element. Complications occurred in 5 cases, resulting in a success rate of 82.1%. When actual treatment planning did differ from the guideline, a legitimate explanation was given or supporting literature was available. In some cases, patient factors have been the reason to deviate from the guideline. Conclusions: It could be stated that the examined guideline for autotransplantation describes a convenient procedure for autotransplantation in young patients after dental trauma in anterior teeth in the upper jaw.

Oral Presentation No. 42 The gradation of the color in natural teeth

Teuta Pustina-Krasniqi, Teuta Bicaj, Enis Ahmedi, Linda Dula, Zana Lila, Arlinda Dragusha, Arben Murtezani Dental Clinical Centre of Kosovo, Prishtine, Republic of Kosovo

Purpose: The knowledge of the gradation of the colour in natural teeth is essentially for shade matching in the clinic, during technician work of fixed prosthetic appliances and also for fabricating the resin artificial teeth. The purpose of this study was to analyze the distribution of colour parameters: brightness (B*), chroma (C), hue (H), axes a* (red-green) and b* (blue-yellow), in intercanine sector in maxilla, measured by an intraoral spectrophotometer. Material and Methods: Patients tooth color measurements were performed using an intraoral spectrophotometer Vita Easyshade® (Vita Zahnfabrik, H Rauter GmbH & Co. KG, Bad Sackingen, Germany). The measurements were made in 255 patients in maxillary left central incisors, lateral incisors and canines CI/LI/C/. The data B* a* b*, C and H values were collected. The mean B*, a*, b*, C and H were calculated for central, lateral incisors and canines. The differences of analysed parameters in /CI/LI/C/ segments were tested with descriptive statistics. Results: The mean values for the group of 255 subjects were as follows: B*, a*, b*, C and H (81.6; 0.67; 21.6, 21.7 and 92.7). Conclusions: Based on results, the lightness was higher in the cervical and middle segments of the analysed teeth. The mean value of chrome in the cervical segment was much higher than in the middle segment, respectively incisal segment of analysed central incisors, which shows that the colour in the cervical part is more saturated.

Oral Presentation No. 43 Restorative aspects after autotransplantation in young patients with traumatized dentitions

Marcel Linssen, Hans van Pelt, Manfred Leunisse, Dick Barendregt, Rob Groot, Michiel Lieshout Dental practice, Rotterdam, The Netherlands

Purpose: The aim of this presentation is to present a biological solution for clinical dilemmas in young patients with missing teeth or teeth at risk after dental trauma. Materials and Methods: Over the past ten years we have developed an interdisciplinary treatment approach combining, surgery, orthodontics and prosthodontics which give excellent and predictable results, fitting in a lifetime treatment plan. Results: Autotransplantation of teeth with an open apex has a long and well documented history. The use of fully developed and endodontically treated teeth for autotransplantation is, in general, not considered to be an option. In our clinic however we have the same success rates for both options. In young patients there is a need for tooth replacement options not interfering with growth of the dento-alveolar complex. Ankylosis after trauma shows what kind of problems may occur if we

49 39th Annual Conference of the European Prosthodontic Association do not take facial growth into account. Growth of the facial height continues over a much longer period than generally is considered in the decision making of implant placement. Conclusions: Autotransplantation, if carried out carefully, on time, and by a team of well trained specialists, is a more than promising solution in young patients with missing teeth or teeth at risk. This treatment option should be taken in consideration more often as an alternative for bonded retainers or implants. Understanding the biology of the periodontal ligament, the effect of orthodontic forces on this ligament as well as restoring the dental anatomy with composites is the key to success.

Oral Presentation No. 44 Is there consensus among specialized dentists and oral surgeons for autotransplantation after loss of anterior teeth in the upper jaw in young patients?

Marliek Ravenshorst, Hans van Pelt, Dick Barendregt, Pieke Wagemakers University of Groningen, University Medical Centre Groningen, Dental School, Department of Fixed and Removable Prosthodontics, The Netherlands

Purpose: The aim of this research was to investigate the commonalities and differences regarding the treatment with autotransplantation in training hospitals in the Netherlands. Additionally the indication for autotransplantation is being examined in young patients (7–16 years) after loss of one or more anterior teeth in the upper jaw by trauma. Materials and Methods: Specialized dentist and oral surgeons in dental training hospitals have given their treatment vision by answering a questionnaire on several cases and the treatment procedure of autotransplantation. The reported case reports were selected from the patient records of Proclin Rotterdam. Four groups of patients could be distinguished based on the lost element(s): loss of one central incisor, loss of both central incisors, loss of a lateral incisor and loss of both central and lateral incisors. From each group a case report was selected. The questionnaire was based on the available literature and the guideline autotransplantation from the Clinic for Periodon- tology Rotterdam. Results: There is no widespread support for the treatment with autotransplantation of the patients in the case reports. The results show that the key factors for choosing autotransplantation are the presence of a suitable donor element and the need for orthodontic treatment. With regard to the treatment procedure, there was division among the respondents. This was in line with the literature. Conclusions: In the Netherlands there is no consensus to treat loss of anterior teeth by trauma with autotransplantation. It is despite the high success – and survival rates reported in the literature.

Oral Presentation No. 45 Prosthetic rehabilitation of growing patients with ectodermic dysplasia

Ioli Ioanna Artopoulou, Aspasia Sarafianou, George Papavasileiou National and Kapodistrian University of Athens, School of Dentistry, Department of Prosthodontics, Greece

Purpose: Ectodermic dysplasia (ED) is a hereditary condition diagnosed in childhood that is characterized by developmental and morphological abnormalities of anatomic structures derived from the ectoderm. Multidisciplinary management and team approach are essential for providing optimal diagnostic and follow-up care for the patients and their families. Several conventional prosthetic treatment methods are available for the oral rehabilitation of ED patients, but definitive implants still remain a challenge for the growing population. To overcome problems associated with definitive implant treatment, provisional implants became an option for the rehabilitation of the growing ED patient.

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Materials and Methods: Clinical cases illustrating the prosthetic rehabilitation of young patients with ED will be presented. Treatment regimens include conservative restorative modalities and conventional prostheses, such as complete dentures, overdentures, and removable partial dentures, as well as the fabrication of provisional implant supported prostheses. Advantages, disadvantages, and indications of the discussed treatment options will be presented. Results: The discussed treatment modalities appeared to be effective in the management of young patients with ED. Conclusions: Effective management of growing patients with ectodermic dysplasia consists of a true multidisciplinary approach involving a paediatric dentist, an oral and maxillofacial surgeon, an orthodontist, and a prosthodontist. The prosthodontist is an integral member of the therapeutic team, since oral rehabilitation is of utmost importance in the management of ED, because it assists patients develop a normal appearance and a positive self-image, restoring their quality of life.

Oral Presentation No. 46 The effect of a key-way preparation on fracture resistance of teeth restored with different post systems

Eda Ozdere, Filiz Aykent Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: The aim of this in vitro study is to evaluate the effect of key-way cavity on the fracture resistance of different post-core systems. Materials and Methods: Seventy single-rooted extracted mandibular second premolars were endodontically treated and divided into 4 groups. The control group consisted of teeth restored without post-core. Group 1 was restored with cast post-cores, group 2 with fibre posts and composite cores, and group 3 with zirconia post-cores. Key-way cavities were performed to the half of the specimens in group 1, 2, and 3. The posts were cemented using adhesive resin cement. All teeth were prepared with a circumferential shoulder including a 2 mm ferrule, restored with Ni-Cr crowns and thermocycled. The compressive test was performed in a universal testing machine with a crosshead speed of 1 mm/min until failure revealed. The fracture load (N) was recorded and the data were analyzed with one-way ANOVA and Tukey’s Honestly Significant Difference test. Results: Statistical analysis revealed that control group had significantly higher failure thresholds than other groups. The lowest fracture strength mean was recorded in fibre group. The key-way increased the mean fracture strength value in zirconia and fibre groups. However it caused the decreasing fracture strength in cast post-core group. This increase and decrease in the fracture strength values were not found statistically significant (p < 0.05). Conclusions: Within the limitations of this study, the results suggest that key-way cavities can be recommended when cast post-cores, fibre post and composite cores and zirconium post-cores used.

Oral Presentation No. 47 Immediate loading screwed crowns on 3.0 implants: A 3-year follow-up

Rafael Martinez-de Fuentes, Pedro Infante-Cossio, Diego Cañadas-Rodriguez, Ana Orozco Varo, Bruno Pereira, Emilio Jimenez-Castellanos University of Seville, School of Dentistry, Spain

Purpose: Immediate loading implant therapies in the anterior aesthetic area in small mesiodistal spaces, narrow bone ridges or limited interradicular spaces are a challenge for dentists. The introduction of 3.0 mm implants have solved the said complications but only for cemented restorations

51 39th Annual Conference of the European Prosthodontic Association as there are no abutments in most of implant systems for screwed prosthesis. The NobelActive Im- plant 3.0 presents a great variety of abutments for all restorations including screwed solutions. The purpose of this work is to assess the advantages or disadvantages of immediate loading screwed crowns on NobelActive 3.0 implants during a 3-year period. Materials and Methods: We present several clinical cases in which we show the clinical and laboratory procedure of making screwed crowns on NobelActive implants placed within the first 24 hours. Results: Preliminary results of the clinical trial show, that success rate of implant after 3 years were 93.33%. In literature we have not found any published papers regarding the use of 3 mm implants for immediate loading using screwed crowns. Conclusions: The screwed crown on NobelActive 3.0 implants is a valid alternative for immediate loading.

Oral Presentation No. 48 Veneer firing effects on zirconia

Hasan Murat Aydogdu, Murat Eskitascioglu Yuzuncu Yıl University, Turkey

Purpose: To observe dimensional changes during veneer firing on zirconia frameworks sintered with three different programs. Materials and Methods: 72 zirconia single crown frameworks were randomly assigned to three groups and sintered with three different programs with durations of 8 hours (A), 2 hours (B) and 10 minutes (C). A Toolmaker’s microscope was used to take marginal gap measurements from 36 equidistant points; also measurements to calculate the projection area and perimeter between four marked points on each occlusal and buccal surface were taken. All frameworks were subjected to 5 veneer firings without applying porcelain to observe the insulate effect of heat treatment. All dimensional and marginal gap measurements were repeated after veneer firings. Results: Marginal gap values before and after veneer firings were 37.61 μm – 35.98 μm for group A; 36.68 μm – 33.06 μm for group B; 33.28 μm – 30.48 μm for group C. The change in marginal gap was insignificant for group A, significant for groups B and C (p < 0.05). The occlusal surface dimensional changes of groups A, B and C were -0.163%, -0.181%, -0.086% for perimeter and -0.321%, -0.300%, -0.197% for area respectively. Buccal surface dimensional changes of groups A, B and C were 0.178%, 0.144%, 0.257% for perimeter and 0.340%, 0.313%, 0.556% for area respectively. There is no significant difference between these three groups regarding surface dimensions (p > 0.05). Conclusions: Veneer firing caused shrinkage in occlusal surfaces and enlargement in buccal surfaces. Marginal gap values decreased after veneer firing in all groups. *This presentation is drawn from data gathered for the doctoral dissertation of Hasan Murat Aydoğdu at the Yuzuncu Yıl University in 2015.

Oral Presentation No. 49 Accuracy of vinyl-polysiloxane and polyeter one-step impressions in-vivo

Aslıhan Köroğlu Kale, Tuncer Burak Özçelik, Işıl Özcan, Suphi Deniz Somay Mustafa Kemal University, Faculty of Dentistry, Hatay, Turkey Başkent University, Faculty of Dentistry, Ankara, Turkey

Purpose: To evaluate the accuracy of vinyl-polysiloxane and polyether impressions made in daily practice using the one-step technique. Materials and Methods: The impressions (n = 140) for fixed-dental-prostheses made in daily prac-

52 39th Annual Conference of the European Prosthodontic Association tice by 3 prosthodontists were visually inspected and rated by an experienced another prosthodontist. The respective casts of the impressions were also subjected to visual evaluation by an experienced dental technician and rated. A structured scale was used for the ratings of the impressions and casts with Alpha (excellent; no defects), Bravo (acceptable; small defects), Charlie (inadequate; defects that require remaking of impression) and Delta (unacceptable; substantial defects like at preparation finish lines) rates. Results were statistically compared. Results: Scale rate results were calculated as 76 (54%) for Alpha, 53 (38%) for Bravo, 4 (3%) for Charlie, 7 (5%) for Delta and 63 (45%) for Alpha, 70 (50%) for Bravo, 2 (1%) for Charlie, 5 (4%) for Delta regarding all the impressions and casts, respectively. Of Alpha rates 45% were polyether and 55% were vinyl-polysiloxane; of Bravo rates 57% were polyether and 43% vinyl-polysiloxane, of Charlie 50% were polyether and 50% vinyl-polysiloxane, and of Delta 57% were polyether and 43% vinyl-polysiloxane for the impressions. The results were statistically influenced by the inter-operator variability. The number of abutments, location of the preparations, and bleeding at the preparation side had no effect on the impression accuracy. No statistical difference was found between the materials regarding quality of the impression. Conclusions: Considering the limitations of the study, the impressions made of vinyl-polysiloxane and polyether for fixed dental prostheses using the one-step technique are both highly accurate.

Oral Presentation No. 50 Color measurement of composites: Is the VITA Shade Guide the reference?

Alexander Schryvers Catholic University of Leuven, Faculty of Medicine, Department of Oral Health Sciences, Belgium

Purpose: The objective of this in vitro study was to measure the difference in color between similar shades of two different Vita-based resin composites. In addition, an experimental composite (non- Vita based), of which the shades are based on the natural aging process of teeth, was tested. Materials and Methods: Two Vita-based resin composites; Filtek Supreme XTE (3M ESPE) and Clearfil Majesty ES-2 (Kuraray); and an experimental (non-Vita based) composite; Essentia (GC); were tested. The shades tested for the Vita-based resin composites were: A1, A2, A2 (enamel, dentin and body shades). For Essentia: 3 dentin shades and 2 enamel shades were tested. Com- posite samples were made in standardised thicknesses: enamel (0.5 mm), dentin (1.5 mm), body (2 mm). The CIE-Lab values of these specimens (enamel, dentin, enamel+dentin, body), and the VITA tabs A1, A2 and A3, were measured with a spectrophotometer (SpectroShade MHT) on a white and black background. Differences in Lab values (Δa*, Δb*, ΔL*), differences in color (ΔE) and the translucency parameter (TP) were calculated. Results: Perceptible color differences (ΔE > 3.7) were measured between similar composite samples (enamel, dentin, enamel+dentin, body, Vita tabs). The range of rE between the same shade- designated samples is 0.7 – 18.0. That of ΔTP is 2.9 – 15.0. The largest variation was noticed for the L* values: 0.3 – 15.1 and a* values: 0.7 – 5.6. For Essentia, a trend of increasing TP, a* and b* values has been recorded for the enamel and dentin shades becoming darker. Conclusions: Perceptible color differences were present between the three composite brands. The experimental composite showed a more gradual change in Lab-values between the different dentin and enamel shades (from light to dark), imitating the natural aging process of teeth.

Oral Presentation No. 51 Survival rate of indirect lithium disilicate restorations after 5, 10 and 17 years

Carolien Vinkenborg, A. W. J. van Pelt University of Groningen, University Medical Centre Groningen, Dental School, Department of Fixed and Removable Prosthodontics, The Netherlands 53 39th Annual Conference of the European Prosthodontic Association

Purpose: The aim of this research was to investigate the long term survival of indirect lithium disilicate (LDS) restorations that were placed between 1997 and 2008. Materials and Methods: 55 indirect LDS restorations (e.max Press and Empress2) that were placed in the period 1997–2008 in 9 patients have been evaluated. It concerned 47 conventional LDS restorations (partial and full coverage) and 8 “endocrowns” for the endodontically treated teeth (premolars and molars). Intra-oral inspection of the LDS restorations was carried out by using a format, based on a list of criteria provided by Hickel. Each criterion could be given a score 1–5. Scores 1–4 were classified as “good” or “repairable”. Score 5 was classified as failure. Results: The percentage of survival after 17 years was 90.9%. The cumulative survival proportion was 98% after 7.9 years, 93% after 8.9 and 78% after 17.3 years (Kaplan-Meier analysis). The mean survival time was 16.7 years. 5 out of 55 LDS restorations were classified as failure. For 4 restorations, the cause of failure was secondary caries. In 1 case the crown had debonded. None of the failures were “endocrowns”. Conclusions: Based on this research, LDS can be regarded as a strong and fracture-load resistant material. Secondary caries was the main reason for failure of LDS restorations. Low sugar intake and good oral hygiene are beneficial for the longevity of restorations. “Endocrowns” are a good restorative option for molars and possibly premolars. Regarding the assessment of restorations, a high level of subjectivity exists despite the use of a format.

Oral Presentation No. 52 Current trends in teaching tooth colour selection and communication in prosthodontics

Aspasia Sarafianou, Phophi Kamposiora, Ioli-Ioanna Artopoulou University of Athens, Dental School, Greece

Purpose: Successful colour matching of prosthetic restorations is a significant factor of patient satisfaction and acceptance. The purpose of this presentation is to outline the current status and the methods taught to dental students concerning colour selection and communication in prosthodontics. Materials and Methods: Visual determination systems (shade guides) and digital colour selection systems taught at predoctoral and postdoctoral level at the University of Athens, Dental School, were assessed. The techniques employed by dental students for colour communication with the dental lab (verbal instructions, written instructions, digital photography) were also outlined. Results: The most frequently used shade guides at predoctoral level were Vitapan Classical and Vitapan 3D Masterguide. Predoctoral students had received education on digital colour selection systems through courses, but they had not been using them for colour selection, while written instructions to the dental lab were routinely used for colour communication. The Vitapan 3D Master- guide was a common shade guide among postdoctoral students. The clinical use of digital colour selection systems at postdoctoral level was common. Communication of tooth colour at postdoctoral level was routinely achieved through written instructions, verbal communication and digital photography. Conclusions: Future general dentistry practitioners may largely benefit from familiarization with digital photography and digital instruments used in tooth colour selection and communication. The incorporation and routine use of these techniques in the predoctoral dental curricula may result in higher restoration success and patient acceptance.

Oral Presentation No. 53 Effect of method, expertise and inter-examiner variability in evaluating crown preparations

Syed Rashid Habib, Mohammed Al Amri, Haneef Sherfudhin King Saud University, College of Dentistry, Riyadh, Saudi Arabia 54 39th Annual Conference of the European Prosthodontic Association

Purpose: The purpose of this study was to compare the subjective (glance and grade) with the Objective (criteria based) grading, investigate inter and intra examiner difference in the grades and determine difference in the grades of anterior and posterior. Materials and Methods: Two faculty staff members with ten years of clinical and teaching experience and two demonstrators with no teaching experience, evaluated tooth preparations performed on two ivory teeth (#21 and #46) in 140 minutes by 74 third year dental students. The preparations were graded subjectively (out of 10) and objectively by each of the evaluators. The values were analyzed by using parametric tests in SPSS setting value of significance at 5 percent. Results: The study revealed that the examiners awarded high scores by objective than the subjective method of grading. Inter-examiner comparison showed a statistically significant difference (p < .05) between the Demonstrator-2 and the rest of the examiners for the subjective method of grading and between Faculty-1 and all the rest of the examiners by objective method. Intra examiner comparison of subjective and objective methods of grading showed a statistically significant difference (p < .05) for two of the examiners. Comparing the grades for anterior and posterior teeth by objective method showed a statistically significant value (p < .05). Conclusions: There was no consistently preferred grading method and there were variations in the grades by the evaluators. Higher grades were scored by objective method of grading and junior faculty awarded higher grades. Non-significant difference between grades of anterior and posterior teeth was found.

Oral Presentation No. 54 Histo-morphological study of functional overload (clinical-experimental study)

Alketa Qafmolla, Leart Berdica, Ruzhdie Qafmolla University of Medical, Faculty of Stomatology, Tirana, Albania

Purpose: Traumatic occlusion is a continuous overload of dental system in chewing function which causes various damages in periodontium. This overload is visible not only in the full dental system but also in the lack of teeth. Histo-morphological changes ore noticed not only in the soft tissues but also in the periodontium and alveolar process with their own atrophy. The aim of our study is to investigate the histo-morphological changes in the periodontium of experimental animals (guinea- pigs) comparing them to the morphological changes of the patients. Materials and Methods: In this study, we have investigated and treated 108 of patients, at the age of 20–70 for a period of more than 10 years. In our study, we have taken into consideration overload in the oral cavity. We have also studied the histo-morphological changes of functional overload in the experimental animals. Results: The main cause of functional overload of teeth is the absence of substitution for a long period of time and the prosthesis which are badly put. We noticed macroscopic and microscopic changes in the periodontium of patients and animals, too. In the patients, the macroscopic changes were gingival hypertrophy, the damage of contact point, the teeth movability and their displacement. Radiology showed us vertical and horizontal atrophy. In the experimental animals, histo-morphological changes were shown in the damage of periodontal ligaments, hematopoietic disorders of pulp and necrotic lesions. Conclusions: The results of clinic treatment of patients were based on the subjective and radiological data before and after treatment where functional overload interruption was observed.

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Oral Presentation No. 55 Impact of removable partial dentures on masticatory efficiency and comparison with natural dentition

Linda Dula, Kujtim Shala, Gloria Staka, Teuta Pustina, Teuta Bicaj, Zana Lila, Enis Ahmedi, Arlinda Tmava University Dentistry Clinical Centre of Kosovo, Prishtina, Republic of Kosovo

Purpose: Mastication is one of the most important functions of the stomatognathic system. It is a process of cutting and chewing food into small particles the first step of digestion achieved by teeth. The aim of this study was to evaluate the impact of removable partial dentures (RPDs) on masticatory efficiency and comparison with natural dentition. Materials and Methods: A total of 107 patients with (RPD) and of 101 students with natural dentition as a control group participated in this study, in University Dentistry Clinical Centre, Prishtina, Kosovo. For the masticatory efficiency test, 5.0 g of peanuts were put into patients mouths for them to chew for 30 s and recorded the number of strokes. The suspension was measured by 722–2000 Spectrophotometer in absorption of 590 µm. Masticatory efficiency measured before, after insertion the RPD, then one and three months after insertion the RPD. Level of significance was set at p < 0.001. Results: A statistically significant difference was found for masticatory efficiency between students and patients before, after insertion the RPD, then one and three months after insertion the RPD (p < 0.001) with Dunn’s Multiple Comparison test. With Kruskal-Wallis test was found statistically significant differences on masticatory efficiency by groups (KW = 472.3, p < 0.001). Conclusions: Rehabilitation of dentitions with RPD improved patients’ masticatory efficiency. In- crease of masticatory efficiency of RPD wearers was also associated with an increased number of masticatory strokes. Masticatory efficiency of students with natural dentition as a control group was much better compared to masticatory efficiency of patients with RPDs wearers.

Oral Presentation No. 56 The reasons for acceptation or refusing the recommended prosthetic treatments

Sherif Shaqiri, Kaltrina Shaqiri Tetova, Macedonia

Purpose: Our aim in this study is: 1. To analyze the frequency of recommended prosthetic treatments; 2. To show the frequency of accepted prosthetic treatments; 3. To show the frequency of refused prosthetic treatments; 4. To determine the correlation between them. Materials and Methods: Between years 2009 and 2014, were examined 1785 of patients which in clinic for prosthetic dentistry “Protetika Ag” in Tetova have asked for prosthetic treatment. From this total, 52.83% were males and 47.17% females. Their age ranged from 13 to 82 years, with average age 48.2 years. The gained data were evidenced in the work sheet for each patient separately according WHO, adapted and modified by the nature of our study. The statistically significance of results from our study is showed with: T-student fisher test; Coefficient of probability (p); Coefficient of correlation (Rxy). Results: The gained results showed that: 1. Dentures were recommended in a high per cent of 24.48. 2. In 46.19%, the costs were the crucial reason for acceptance of recommended treatment. 3. The crucial reason for refusing the recommended treatment was also its cost. Conclusions: 1. In our treated patients the stomatoghnatic system is disordered with wide toothless areas and disfavourable distribution of remained teeth. 2. Covering of cost for prosthetic treatment from the side of Health Insurance Fund influences the choice of patients in prosthetic appliances. 3. The lack of awareness among patients about the importance of oral health in one side, and neg- ligence for need of preventive measures on the other side, influence on refusing of recommended treatment. 56 39th Annual Conference of the European Prosthodontic Association

Oral Presentation No. 57 Patient’s satisfaction with removable partial dentures

Blerim Kamberi, Kujtim Shala, Linda Dula University Dentistry Clinical Centre of Kosovo, Prishtina, Republic of Kosovo

Purpose: Removable partial denture (RPDs) therapy is an acceptable form of treatment that provides an increased spectrum of restorative options: improving aesthetics, masticatory function and stabilizing dental relationships for patients. The aim of this study was to evaluate patient’s satisfaction with RPDs retention, chewing ability, aesthetics, while wearing RPD in a five-year worn period. Materials and Methods: A total of 63 patients with RPDs, participated in this study. It was examined ninety-one RPDs, 75 with clasp-retained and 16 were RPDs with attachments. There were 28 females and 35 males, aged between 34–79 years. The data’s were collected from survey questionnaire, in University Dentistry Clinical Centre, Prishtina, Kosovo. Patients graded their satisfaction with their RPDs in total and then graded retention, chewing ability, aesthetics, while wearing dentures by using a scale 1 to 4. The level of RPDs acceptance was classified as “excellent”, “good”, “medium” and “bad”. RPDs success was graded in three categories based on function and condition: complete success, partial success and failure. Results: According to denture design of RPD’s with Fisher exact test we confirmed statistically significant difference (p = 0.008) of patient’s success of RPD’s with or without attachment. Reten- tion, chewing ability, aesthetics proved no statistically significant difference with X 2 test of patients´ satisfaction of RPD’s with or without attachment. Conclusions: Oral rehabilitation with RPDs was considered satisfactory after five years of use by most of patients (Cosme DC et al, 2006). Patients are generally satisfied more with RPDs with attachment based on level of retention, chewing ability, aesthetics.

Oral Presentation No. 58 Effect of denture cleansers on matrice retention of precision attachments

Umut Cakan, Tuba Yilmaz, Haluk Baris Kara Istanbul Medipol University, Faculty of Dentistry, Turkey

Purpose: The purpose of this study was to evaluate the changes in retention of plastic precision attachment matrices after exposure to various denture cleansers. Materials and Methods: One control and four test groups (10 pairs each) of matrices (Bredent VKS-SG) were soaked for the equivalent of 6 months of clinical use in the following solutions: Water (control), Corega, Protefix, 5% Sodium hypochlorite (NaOCl, 1 : 10 diluted) and Listerine mouthwash. A universal testing machine set at a crosshead speed of 0.5 cm/min was used to perform one pull. The peak load-to-dislodgement was recorded to reflect changes in the retention of the matrices after soaking. Data were analyzed by one-way ANOVA followed by Tukey’s Honestly Significant Difference test. A p < 0.05 was considered significant. Results: Denture cleansing solutions significantly affected the retentive values of matrices (p< 0.01). NaOCl increased the retentive values of the matrices (19.02 ± 2,26 N) when compared to the control group (15.67 ± 2.75 N). There was no significant difference in the retentive values of attachments soaked in Corega, Protefix or Listerine when compared to the control group. Conclusions: The use of NaOCl may be recommended for cleaning of the removable partial dentures with precision attachments because of its increasing effect on the retentive values of the matrices within the limitations of the test conditions.

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Oral Presentation No. 59 Comparison of two techniques to achieve postdam for maxillary dentures

Hanum Kassim Zethy, M. H. Shaharuddin, N. S. A. Anuar Adnan University Technology MARA, Faculty of Dentistry, Selangor, Malaysia

Presentation was cancelled.

Oral Presentation No. 60 The effect of removable partial dentures on the periodontal health of abutment and non- -abutment teeth

Kujtim Shala, Linda Dula, Enis Ahmedi, Zana Lila, Teuta Pustina, Teuta Bicaj, Arlinda Tmava University Dentistry Clinical Centre of Kosovo, Prishtina, Republic of Kosovo

Purpose: Removable partial denture therapy (RPD) is an adequate form of treatment for patients with missing teeth. The aim of this study was to evaluate the effect of (RPD) on the periodontal health of abutment and non-abutment teeth. Materials and Methods: A total of 107 patients with (RPD) participated in this study. It was examined 138 (RPD), they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth: plaque index, calculus index, bleeding on probing, probing depth (mm) and tooth mobility index. These clinical measurements were taken immediately before insertion the RPD, and subsequently one and three months after insertion. Level of significance was set at p < 0.05. Results: The mean scores for PLI, CI, BOP, PD, and TM index of the abutment teeth and non- abutment teeth were no statistically significant at the time of insertion of RPD. After one month PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After three months there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (p > 0.05). Conclusions: With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene we can prevent the periodontal diseases.

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9. POSTER PRESENTATIONS

Poster Presentation No. 1 Evaluation of long-term storage effects on resin composites surface properties

Neslihan Cokuk, Emine Kara, Beyza Unalan Degirmenci, Mujde Sevimay Yuzuncu Yil University, Faculty of Dentistry, Campus/VAN, Selcuk, Turkey University Faculty of Dentistry, Konya, Turkey

Purpose: To evaluate the effect of long-term storage in distilled water on surface hardness and roughness of different composites. Materials and Methods: Ninety disc-shaped specimens (10 × 2 mm) of three different brands of resin composites shades A2 were prepared (Tetric N-Ceram, Filtek Z250, GC Gradia Direct Pos- terior) and randomly divided into 9 groups (n = 10) according to surface treatments [SIC 1000 papers, Enhance Finishing System (Dentsply) and Sof-Lex aluminium oxide discs (3M/ESPE)]. Av- erage surface roughness (Ra) and micro-hardness were measured 24 hours after curing and after 36-months of storage in distilled water (370 °C). Changes in percentage were taken and factorial ANOVA was employed for statistical analysis. Results: Factorial ANOVA revealed that there was no statistically significant differences among materials, and surface treatments in term of changes in percentage of micro-hardness measurements of resin composites (p > 0.05). Nevertheless, in term of changes in percentage of surface roughness there were statistically significant differences among materials and surface treatments (p < 0.01). The highest result of change in percentage of surface roughness was in Enhance Finishing System groups (253.35 ± 23.54% – group 2; 237.8 ± 151.22% – group 5; 99.56 ± 17.36% – group 8). CG Gradia with Soflex group obtained the highest change in percentage of micro-hardness (-9.34 ± 2.15% – group 3), and the lowest result of micro-hardness was the Filtek Z250 with Soflex group (0.58 ± 6.12% – group 6). Conclusions: There was no correlation between micro-hardness and surface roughness. Polishing with Enhance Finishing System showed highest surface roughness after the storage in distilled water for 36 months.

Poster Presentation No. 2 The marginal adaptation of metal frameworks prepared by different methods

Duygu Sarac, Baris Pasali, Necati Kaleli Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthetic Dentistry, Turkey

Purpose: The purpose of this study was to compare the marginal fit of metal frameworks prepared by conventional casting, induction casting and milling. Materials and Methods: Forty implant abutments were embedded in to acrylic blocks. Forty Co-Cr single crown metal frameworks were prepared on implant abutments while ten of them were prepared by conventionally casting (group C), 10 by induction casting (group IC), 10 by milling from half-sintered metal block (group MH) and 10 by milling from full-sintered metal block (group MF). Marginal gap of metal frameworks were measured on mesial, distal, buccal and lingual area by using stereomicroscope. Data were statistically analyzed by one-way ANOVA (α = 0.05). Results: A significant difference was found between the groups C, IC, MH and MF (p > 0.05). The milling groups showed better marginal adaptation than others. Conclusions: All samples showed a clinically acceptable marginal adaptation, which is lower than 120 μm. However, milling of full-sintered metal blocks showed better marginal fit, which may be a result of milling highly-resistant metal blocks without residual thermal stress.

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Poster Presentation No. 3 Effect of metal primers on adhesion between composite and titanium

Ender Kazazoğlu, Yüksel Yazıcıoğlu, Ayşe Yalnız Yeditepe University, Dental School, Department of Prosthodontics, Istanbul, Turkey

Purpose: To evaluate the shear bond strength (SBS) of using four different metal primers between titanium alloy (Ti6Al4V) and indirect laboratory composite. Materials and Methods: Four chemically different metal primers (GC Metal Primer II, Shofu ML Link, Ivoclar Vivadent SR Link, Bisco Z Prime) and one laboratory composite system (GC Gradia) were bonded on the 80 Ti6Al4V disks to test SBS. These 80 samples were divided into 2 main groups; first group (a) treated by thermal cycle and the other group (b) had no thermal cycle. These2 groups were also divided into 4 subgroups according to used metal primers. After sand-blasting of machined Ti6Al4V disk samples, for all groups Ivoclar Vivadent SR Nexco Paste opaquer and GC Gradia indirect laboratory composite were used, however, for group 1a/b, group 2a/b, group 3a/b, group 4a/b; GC Metal Primer II, Shofu ML Link, Ivoclar Vivadent SR Link, Bisco Z prime metal primers were used respectively. All samples were tested by Instron for SBS. Finally, debonded surfaces were evaluated by Modified Adhesive Remnant Index (ARI). Results: Before thermal cycle, group 1b; after thermal cycle application, group 3a showed the highest SBS value (p < 0.01). Some groups showed higher mean of SBS after thermal cycle application (group 2a/b, group 3a/b). In all debonded surfaces when detected by modified-ARI, incidence score 2 (43) was more frequent followed by score 1 (36), score 2 (1) and none of samples showed score 3. Conclusions: Different but chemically appropriate metal primers can be used for preparing or repairing indirect laboratory composite as a superstructure for Ti6Al4V.

Poster Presentation No. 4 Effect of different surface treatments on bond strength of resin cement to a CAD/CAM restorative material

Kubilay Barutcigil1, Mehmet Mustafa Özarslan1, Esra Kul2, Çağatay Barutcigil3, Ulviye Sebnem Buyukkaplan1 1Akdeniz University, Faculty of Dentistry, Department of Prosthetic Dentistry, Antalya, Turkey 2Atatürk University, Faculty of Dentistry, Department of Prosthetic Dentistry, Erzurum, Turkey 3Akdeniz University, Faculty of Dentistry, Department of Restorative Dentistry, Turkey

Purpose: This study investigated the effects of different surface treatments on the shear bond strength of self-adhesive resin cement to a novel CAD/CAM hybrid ceramic material. Materials and Methods: A novel CAD/CAM hybrid ceramic restorative material (Vita Enamic) was used in this study. Sixty resin blocks specimens were prepared and specimens were divided into six groups for each surface treatment method (n = 10); Group 1: control (no treatment), Group 2: sandblasted by silicate-coated alumina particles (CoJet Sandblasting), Group 3: 50 µm Al2O3 sandblasting, Group 4: 10% hydrofluoric acid, Group 5: no surface treatment + universal adhesive (3M Single Bond Universal), Group 6: 200 mJ, 10 Hz 2 W Er,Cr:YSGG laser treatment. A self-adhesive resin cement (3M U200) was built-up on each treated surface using a cylindrical mould (2 × 4 mm) and incrementally filled. The shear bond strength was measured with a universal test machine. Data were analyzed using a one-way ANOVA and a Duncan test (p = 0.05). Results: Shear bond strength mean values ranged from 7.75 to 10.73 MPa. All surface treatment methods enhanced the bond strength values compared with the control group but there was a statistically significant difference between group 5 and the control group (p < 0.05). There were no significant differences between other treatment methods. Conclusions: Surface treatments of hybrid ceramic resin blocks could enhance the bond strength

60 39th Annual Conference of the European Prosthodontic Association to resin cement. However, using of Single Bond Universal without surface treatment showed higher bond strength value.

Poster Presentation No. 5 Assessment of common finishing and polishing techniques on cast Co-Cr plates with various methods

Petra Baumann1, László Seress2, Béla Kocsis3, Gyula Marada1, Márta Radnai1 1University of Pécs, Medical Faculty, Dental School, Department of Prosthodontics, Hungary 2University of Pécs, Medical Faculty, Central Electron Microscope Laboratory, Hungary 3University of Pécs, Medical Faculty, Department of Medical Microbiology and Immunology, Hungary

Purpose: It is essential to use highly polished surfaces in removable prosthodontics to avoid plaque formation. The aim of this study was to evaluate the surface characteristics of cast metal plates going through the common finishing methods, and its effect of bacterial adhesion. Materials and Methods: Rectangular Co-Cr alloy samples (10 × 20 × 1 mm) were casted. The samples were treated as follows; method 1: sandblasting using 250 µm Al2O3 grit size, method 2: sandblasting and electro polishing for 7 min, method 3: sandblasting, electro polishing and polishing with rubber polishers, goat hair brush and polishing paste. The samples were examined with scanning electron microscope (SEM), and pictures were taken digitally. In addition, the surface of the samples was examined with an INCA x-stream and MICS (Microscope Image Capture System) analyzer for the percentile composition of metallic elements in the samples. Samples treated simi- larly were incubated with Streptococcus mutans on blood agar plate for 3 days and adhesion was checked with SEM. Results: The optical evaluation showed that the plates with only sandblasting had the biggest roughness, and the smallest resistance to adhesion that went through all of the treatments, as it was expected. In the qualitative examination besides the casting alloy components other elements could be detected in small amount especially on the sandblasted (C, O, Na, Mg, Al, Si, P, S) surface. The attachment of the bacteria was the biggest to the sandblasted surface. Conclusions: Among common laboratory circumstances the regular finishing and polishing of the casted metal plates reached high smoothness and shine showing the methods used were appropriate.

Poster Presentation No. 6 Residual bone height measured by panoramic radiography in edentulous Turkish patients

Ilhan Altinsoy, Sebnem Buyukkaplan, Mustafa Ozarslan, Nurullah Turker, Merve Arslan Akdeniz University, Faculty of Dentistry, Department of Prosthodontics, Antalya, Turkey

Presentation was cancelled.

Poster Presentation No. 7

Surface treatment effect on roughness of ZrO2 used in prosthodontics

Teodor Traistaru1, Mihaela Pantea1, Maria Diana Vranceanu2, Cosmin Mihai Cotrut2 1”Carol Davila” University of Medicine and Pharmacy, Faculty of Dentistry, Prosthodontics Clinic, Bucharest, Romania

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2University Politehnica of Bucharest, Romania Purpose: The aim of this study is to evaluate the influence of mechanical and chemical treatment on ZrO2 roughness. Materials and Methods: Zirconia samples have been manufactured by CAD/CAM technology. By using SolidWorks software, an STL file with the requested dimensions has been generated and imported in the computer aided machine. The experimental samples were obtained with vhf CAM 4-K4 IMPRESSION milling machine. The samples have been sintered and then modified by mechanical (sand-blasting) and chemical (acid etching) treatments. The resulted samples had cylindrical shape with dimensions of 14 × 4 mm. In order to obtain a fitting core it must be considered that zirconia has 20% shrinkage. Results: The influence of mechanical and chemical treatment on zirconia ceramic material is studied by means of chemical composition and microstructure (SEM-EDS), physic composition (XRD) and roughness (surface profilometry).

Conclusions: Practical conclusions regarding the ZrO2 surface treatment are outlined, in order to obtain an enhanced roughness of zirconia bio-ceramic material.

Poster Presentation No. 8 The effect of ultraviolet treatment on the surface properties of YTZ-P: A pilot study

Ahmet Kursat Culhaoglu1, Emre Seker2, Mehmet Ali Kilicarslan3 1Kirikkale University Faculty of Dentistry, Department of Prosthodontics, Turkey 2ESOGU Faculty of Dentistry, Department of Prosthodontics, Eskisehir, Turkey 3Ankara University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: In order to increase adhesion capability, YTZ-P surfaces can be substantially modified by Al2O3 sandblasting. However, this technique has potential negative effects which lead to reduce fracture resistance, on the micro-structure of YTZ-P. The purpose of this study was to investigate the physical effects of ultraviolet (UV) light curing on YTZ-P surface, as an alternative technique. Materials and Methods: Nine plates of machined YTZ-P discs (10 mm in diameter and 2.0 mm thick) were randomly divided into three investigation groups (n = 3) in which were subjected to UV for 15 minutes, 24 hours and not subjected (control). Each group was separately evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) by means of surface topography. Also the hydrophilic status was investigated by contact angle (CA) via a tensiometer. Results: CA findings did not reveal any significant change about the wettability issues. On the other hand, minor topographical changes occurred on experimental samples according to control group, on SEM and AFM images. By the way as an unexpected finding for all treated YTZ-P samples, as application times increased the discoloration increased. Conclusions: It was concluded that UV application is not an effective method for surface treatment of YTZ-P within stated time periods. Future researches may be based on to investigate the effect of longer treatment times and the colour changes of YTZ-P samples.

Poster Presentation No. 9 Shear Bond strength of resin cement to a CAD/CAM restorative material

Mehmet (Mustafa) Özarslan1, Kubilay Barutcigil1, Esra Kul2, Çağatay Barutcigil3, Ulviye Sebnem Buyukkaplan3 1Akdeniz University, Faculty of Dentistry, Department of Prosthetic Dentistry, Antalya, Turkey 2Atatürk University, Faculty of Dentistry, Department of Prosthetic Dentistry, Erzurum, Turkey 3Akdeniz University, Faculty of Dentistry, Department of Restorative Dentistry, Turkey

Purpose: This study aims to evaluate the effects of Er,Cr:YSGG laser irradiation under different 62 39th Annual Conference of the European Prosthodontic Association power settings on the shear bond strengths of a novel CAD/CAM hybrid ceramic resin restorative material (Vita Enamic) to a self-adhesive resin cement. Materials and Methods: Sixty CAD/CAM restorative materials specimens were divided into six groups according to the surface treatment methods as follows: an untreated control group and five groups undergoing surface preparation with Er,Cr:YSGG laser under five different power settings (100, 200, 300, 400 and 500 mJ at 10 Hz for 60 s at 100 µs pulse durations). After 24 hours of storage in water, self-adhesive resin cement (3M U200) was built-up on each treated specimens using a cylindrical mould (2 × 4 mm) incrementally. After all of the specimens were set, shear bond strength tests were performed using a universal testing machine at a crosshead speed of 0.5 mm/ min. The data were analyzed using one-way ANOVA and Duncan post-hoc test (p < 0.05). Results: The highest shear bond strength value was observed in 2 W laser power setting and followed by 1 W power setting. There was a statistically significant difference between 2 W and control group (p < 0.05). The shear bond strength values ranged between 7.13 and 10.56 Mpa. The lowest values were observed in the groups without surface treatment. Conclusions: Higher power settings of the Er,Cr:YSGG laser did not affect the bond strength. So, in lower power setting the Er,Cr:YSGG laser might be used for enhanced bond strength between a novel CAD/CAM restorative and resin cement.

Poster Presentation No. 10 The effect of IPN thermoplastic on mechanical properties of fibre-reinforced composite

Minori Hatta, Akikazu Shinya, Pekka K. Vallittu, Lippo V. J. Lassila The Nippon Dental University Hospital, School of Life Dentistry at Tokyo, Department of Crown and Bridge, Japan University of Turku, Institute of Dentistry and BioCity, Department of Biomaterials Science, Bioma- terials Research Program, Finland

Purpose: To evaluate the effect of interpenetration polymer network (IPN) on mechanical properties of UDMA/MMA based fiber-reinforced composite. IPN-phase was formed either using PMMA or PMMA-co-polymer. Materials and Methods: Materials used in this study were UDMA (90%, Esschem) –MMA (10%, Sigma) based resin. Used IPN-component was either PMMA (150 kD, Sigma-Aldrich) or PMMA- copolymer (150 kD, Sigma-Aldrich). 0.5% or 2% IPN-thermoplastic was added to UDMA-MMA resin having 0.7 wt% camphorquinone and DMAEMA 0.7 wt%. 0.5% PMMA was added to Group1, 5 and 2% PMMA Group 2, 6. PMMA-co-polymer was added to 0.5% (Group 3, 7) and 2% (Group 4, 8) respectively. Total 80 (n = 10/Group) specimens for flexural strength (3-point bending, FS) test were fabricated (2 × 2 × 25 mm). The resin was put in the mould and light cured for 25 min at oven. For fibre-reinforced specimens, one bundle of S-glass fibres (tex 2400, MCX21, Ovens-Corning) were impregnated with each resin for 30 min and then placed in the mould. After placement, resin was put in and light cured for 25 min at oven. The half of specimens was without fibre-reinforcement (Group1–4) and the rest was with fibre-reinforcement (Group 5–8). Specimens of FS test were fixed and load was applied at crosshead speed of 1.0 mm/min, loading span of 20 mm. The results were analyzed by two-way ANOVA. Results: The mean FS without fibre-reinforcement was from 115.6 MPa (Group 4) to 119.3 MPa (Group 1), and FS with fibre-reinforcement was from 458.4 MPa (Group 5) to 505.5 MPa (Group 8). ANOVA showed that there are significant differences between the groups with and without fibre- reinforcement. Addition of IPN-component did not change mechanical properties of FRC. Conclusions: The results showed that the fibre-reinforcement is effective for increasing of flexural strength. Further studies will be needed to evaluate effect of thermoplastic IPN on acrylic resins.

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Poster Presentation No. 11 Correlation between age and residual ridge resorption in edentulous Turkish patients

A. Nagehan Ozevcimen, U. Sebnem Buyukkaplan, M. Mustafa Ozarslan, M. Ertugrul Ciftci, Merve Arslan, Nurullah Turker, Ilhan Altinsoy Akdeniz University, Faculty of Dentistry, Department of Prosthodontics, Antalya, Turkey

Purpose: This study evaluated the relationship between the age and the residual ridge resorption (RRR) in edentulous Turkish patients who were referred to Akdeniz University Department of Pros- thodontics. Materials and Methods: Panoramic radiographs of 140 patients were reviewed. Panoramic radiographs of 79 among the 140 have met the criteria. Criteria consisted of no fracture history, clearly visible anatomic structures and absence of asymmetry. A researcher evaluated the panoramic radiographs using a standardised method. Relationship between residual ridge resorption and panoramic radiographs of 79 among the 140 patients met the criteria. Age was evaluated using t-test (p = 0.05). Results: The results showed that there was no significant relationship between the residual ridge resorption and increasing age. (p = 0.125). Conclusions: Despite the majority of the studies show otherwise, residual ridge resorption may not be affected by age.

Poster Presentation No. 12 Relationship between age and values of PMI and MCW in edentulous patients

Merve Arslan, U. Sebnem Buyukkaplan, M. Mustafa Ozarslan, Nurullah Turker, A. Nagehan Ozevci- men, Ilhan Altinsoy Akdeniz University, Faculty of Dentistry, Department of Prosthodontics, Antalya, Turkey

Purpose: The purpose of this study was to investigate the influence of age and gender on the mandibular cortical width and panoramic mandibular index, using panoramic radiographs of edentulous patients. Materials and Methods: Panoramic radiographs that were taken for routine diagnosis of 79 edentulous patients (38 men and 41 women) were assessed. In addition to gender and age, mandibular cortical width at the mental foramen region was recorded. Panoramic mandibular index was calculated using the ratio of thickness of mandibular cortex to the distance between the mental foramen and the inferior mandibular cortex. Statistical comparisons were performed using t-test. Results: There was a significant relation between the age of men and PMI values compared to women (p = 0.014). On the contrary, MCW values in men had more significant difference compared to women. Conclusions: While mean mandibular cortical width values are stable in women over 60 years, mean mandibular cortical width values decrease significantly in men of the same age group.

Poster Presentation No. 13 Does the height of stabilization splints affect the treatment of temporomandibular disorders?

Halenur Bilir, Hanefi Kurt Istanbul Medipol University, Turkey

Purpose: The aim of this study was to investigate if there are any differences between low height-

64 39th Annual Conference of the European Prosthodontic Association ened stabilization splints (2.0 mm) or high heightened stabilization splints (4.0 mm) for the treatment of temporomandibular disorders. Materials and Methods: 72 female and 6 male patients attended to our study. Randomized numbers were used for dividing patients who would have 2 mm heightened-splints or 4 mm ones. After the stabilization splints were delivered, patients used them during 6 months only night time and they were recalled after 1st month, 2nd month, 3rd month and 6th month for controlling their symptoms. Patients were evaluated using RDC/TMD forms. Results: Although there were statistical differences between low and high heightened-splints for relieving symptoms for myofascial pain related to temporomandibular disorders, they were not related to intracapsular temporomandibular disorders. Conclusions: High heightened stabilization splints could be preferred for relieving symptoms of myofacial pain related to temporomandibular disorders but these results have to be confirmed by other studies.

Poster Presentation No. 14 The boe mineral density impact on residual ridge resorption in postmenopausal female

Evija Nikitina, Daina Spule Riga Stradins University, Latvia

Purpose: The aim was to evaluate the influence of general bone mineral density on the edentulous residual ridge resorption in posmeneopausal female. Materials and Methods: In the present study were 53 postmenopausal women aged 54–86 years (average age 72,0 ± 8,7 years). For all patients were made: dual energy x-ray absorptiometry (DXA) cone beam computer tomography (CBCT). Bone mineral density measurements (BMD) of lumbar spine and both hips by dual energy x-ray absorptiometry (DXA) (Lunar DEXA DPX-NT, GE Medical Systems) were made. From DXA analysis the T-score reading was used. To detect edentulous jaw bone quantity cone beam computer tomography (CBCT) (Next generation i-CAT, KaVo eXam vision) were made. CBCT images were analyzed with KaVo eXam vision software. The level of residual ridge resorption for each patient was determined performing 7 height and 49 width measurements in mandible and 10 height and 30 width measurements in maxilla on CBCT. Edentulous jaw bone resorbtion of the maxilla and mandible were calculated with KaVo eXam vision software. Statical analysis data were seperately analyzed for each edentulous site, calculated by Pearson Correlation. Results: There was negative statistically significant correlation between BMD and width of the mandibular residual ridge. There was no correlation between BMD and maxillary measurements, except in some width measurements in frontal region. Conclusions: There is weak relationship with BMD and edentulous residual ridge resorption in postmenopausal female.

Poster Presentation No. 15 Conversion degree analysis of resin cements beneath different ceramic materials

Özgür Öztürk1, Simel Ayyildiz1, Cem Şahin2, Bülent Pişkin1, Cumhur Sipahi1 1Gulhane Military Medical Academy, Centre for Dental Sciences, Department of Prosthodontics, Kecioren/Ankara, Turkey 2Hacettepe University, Ankara, Turkey

Purpose: Degree of conversion (DC) is one of the important factors that affect clinical performance of resin-based cements. The aim of this study is to evaluate the DC of two dual-cured resin cements

65 39th Annual Conference of the European Prosthodontic Association beneath the different ceramic cores. Materials and Methods: The dual-cured resin cements (Pv; Panavia F 2.0, and Per; Permacem) were photo-activated for 40 s through different ceramic disks 2 mm thick (F; Ceramco 3, E2; IPS Empress II and, Ic; In-Ceram Alumina). The control groups were obtained with dual-cured resin cement specimens without ceramic specimen. Film thickness (0.8 mm) of resin cement specimens were checked using a digital calliper before testing. After 24 h of dry storage at 37 °C, the DC was measured by Fourier Transformed Infrared Spectroscopy (FTIR) at 24 °C and dry storage. Data were submitted to one-way ANOVA and post-hoc Tukey’s test, with a pre-set alpha of 0.05. Results: In Panavia groups, highest values of the %DC were obtained in group Ic-Pv and lowest values of the %DC were obtained in group F-Pv. In Permacem groups, highest values of the %DC were obtained in group Ic-Per, and lowest values of the %DC were obtained in E2-Per. The factors ‘‘ceramic type’’ and ‘‘resin cement’’ were significant, as was their interaction (p < 0.001). For all ceramic type, Permacem showed significantly lower DC than all other groups (p < 0.001). Conclusions: The DC of resin cements may be affected by the type of the ceramic material and chemical composition of the resin cement.

Poster Presentation No. 16 Effects of laser treatments on surface roughness of zirconiumoxide ceramics

Goknil Ergun Kunt1, Gozlem Ceylan1, Ibrahim Duran2, Pelin Ozkan3 1Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Kurupelit, Samsun, Turkey 2Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Kurupelit, Samsun, Turkey 3Ankara University, Faculty of Dentistry, Department of Prosthodontics, Beşevler, Turkey

Purpose: The purpose of study was to investigate the effect of different laser treatments (CO2, Er:YAG) on the surface roughness of yttrium stabilized tetragonal polycrystalin zirconia (Y-TZP) ceramics. Material and Methods: 5 × 5 × 2 mm rectangular prism of forty eight Y-TZP (Zirkonzahn specimens) were prepared. For surface standardization, specimens were gradually ground wet with 600-, 1200- grid silicon carbide papers for 10 seconds each on 300 rpm grinding machine. Specimens of each ceramic were randomly divided into eight groups (n = 6) for control (Group-C), sandblasting with

Al2O3 powder at 2.8 bar for 15 seconds through a nozzle distance of 10 mm (Group-S), two different CO2 laser (Smart US-20D) treatments (Group-3W: 3W, 382 w/cal, Group-4W: 4W, 509 w/cal) and four different Er:YAG laser (Fotona AT) treatments (Group-150SP: 150 mJ,10-Hz with 100µS; Group-150SSP: 150 mJ,10-Hz with 300 µS; Group-300SP: 300 mJ,10-Hz with 100 µS; Group- 300SSP: 300 mJ,10-Hz with 300 µS) treatments. Surface roughness measurements (Ra) were performed using a profilometer. Surface morphologies of the specimens were evaluated under SEM after laser treatment. Results: The data were analyzed with a one-way ANOVA, and mean values were compared by the Tukey HSD test (α = .05). According to the one-way ANOVA results, the highest Ra value was observed in Group-S and the lowest Ra value was observed in Group-150SP. Group-4W showed highest Ra value after sandblasting. There were no statistically significant differences among Group-C, Group-150SSP, Group-300SP, Group-300SSP and Group-3W.

Conclusions: Under the limitations of this study, surface treatment with CO2 laser increased the surface roughness of zirconium oxide ceramics.

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Poster Presentation No. 17 Evaluation of the vertical-bone-height of dentulous and edentulous patients

Begum Buyukerkmen1, Guldane Magat2, Sevgi Sener2 1Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics Dentistry, Turkey 2Necmettin Erbakan University, Faculty of Dentistry, Department of Oral Radiology, Turkey

Purpose: The aim of this study was to analyze difference between the amount of vertical bone height in the dentulous and edentulous mandibles by using the mental foremen as a references. Materials and Methods: A total of 160 panoramic radiographs of 80 dentulous (males MD and females FD) and 80 edentulous (males ME and female FE) were selected. Among the dentulous and edentulous subjects, in both genders, the ratio between the height of the mandible and the distance from the mental foramen and the lower border of the mandible (A/B) were calculated by using Ado- be Photoshop CS4 computer programme. The amount of vertical bone height was then calculated. Results: Measurements were performed in patients over 40 years old. In the dentulous patients; the A/B ratio for males in right side of mandible was 2.49 and in left side of mandible was 2.41. Den- tulous females, in right side of mandible the ratio was 2.43 and in left side of mandible was 2.41. The A/B ratio for the edentulous males in right side was 2.08 and in left side 2.01. In the edentulous females A/B ratio was in right side 1.98 and in left side 2.01. A significant difference was not found among the right and left side of the mandible. Significant differences were found between dentulous and edentulous patients. The comparison of the ratios was non-significant between males and females. Conclusions: The mean bone height in dentulous patients was found to be greater than the mean bone height in edentulous patients on comparison.

Poster Presentation No. 18 Radiotherapy effect on the bond strength of resin luting cement

Onur Şahin, Doğu Ömür Dede, Ayşegül Köroğlu, Yıldıray Özgüven, Derya Özdemir Doğan Bulent Ecevit University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: The purpose of this study was to evaluate the effects of pre- and post-irradiation application on the shear bond strength of self adhesive luting cements to dentin and enamel. Materials and Methods: 32 extracted human maxillary (n = 12) incisors were used in this study. According to preparation depth (0.5 mm and 1 mm) and treatment protocol which includes; irradiation surface (teeth or resin cement) and time of preparation (after or before irradiation) 8 study groups were determined. Specimens were placed in a universal testing machine, metal ring was connected with the cross-head and load was applied to each specimen until the bond between the exposed surface of teeth and resin cement failed. The maximum tensile bond strength was recorded from a personal computer. The shear bond strength results were analyzed using 2-way ANOVA to evaluate the effects of depth of preparation, treatment protocol and their interactions. The mean shear-bond strength values were then compared using the Tamhane’s test. Significance was evaluated at p < 0.05 for all tests. Results: According to the two-way ANOVA results, depth of preparation and treatment protocol and their interactions were significant on shear bond strength on resin cement. For the both 0.5 mm depth and 1mm depth of preparation the mean shear bond strengths for the groups, were significantly (p < 0.05) lower than in control group. Conclusions: Irradiation may have an adverse effect on the bond strength of adhesive luting cement depending on the application sequence.

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Poster Presentation No. 19 Retention force of SynCone pairs made of gold

Mihael Stanojevic1, Irena Mladenovic1, Ivica Stancic², Tomic Slavoljub¹ 1University of East Sarajevo, Bosnia and Herzegowina 2Belgrade University, Serbia

Purpose: Aim of this study was to determine the retention force, depending of a method of fabrication, of double conical crown whit 5º, in the Ankylos SynCone concept, at the beginning of the use, during and after 10,000 cycles. Materials and Methods: In this study we have used a SynCone conical abutment made of titan whit 5° angle and 1.5 mm gingival height, inserted on the implant, as the inner part of the conical pair. For the outer part (SynCone Cap) of the conical pair we have used a: 1. Prefabricate SynCone cap made of gold, that corresponds to the inner part of the conical pair; 2. Casted cap made of gold, which was manually made in a dental laboratory. For this study we have used Kausimulator CS-4.8 (SD MECHATRONIC; Germany) for cycles. The conical pairs have been submitted to 10,000 sepa- ration cycles. We have measured the force on the cycles No 1, No 120 and No 10000. Results: In group 1 we had increase of retention force from F1 to F120 and then a constant force until F10000. In group 2 we had a constant increase of retention force from F1 until F10000. We have found that there is a difference in the first group between F1 and F10000 (p ˂ 0.05) and between F120 and F10000 (p ˂ 0.05). In the second group we have found no statistically relevant difference. Conclusions: It was shown that the SynCone conical crown system could potentially provide adequate and constant retentive force to retain implant-supported overdentures.

Poster Presentation No. 20 Physicochemical and antibacterial properties of a Bis-GMA-free dental resin

Huang Qiting, Jingwei He, Zhengmei Lin, Fand Liu, Eva Söderling, Lippo V. J. Lassila, Pekka K. Vallittu Sun Yat-Sen University, Guangzhou School of Stomatology, Hospital of Stomatology, Department of Conservative Dentistry and Endodontics, Guangdong Provincial Key Laboratory of Stomatology, China

Purpose: The objective of this study was to evaluate the antibacterial activity, physicochemical properties of the quaternary ammonium dimethacrylate monomer IMQ-16 containing UDMA/SR833s resin system relative to Bis-GMA/TEGDMA resin system. It was hypothesized that the physical and chemical properties of the experimental polymers would be comparable with Bis-GMA/TEGDMA polymer and that IMQ-16 monomer could endow the UDMA/SR833s resin with antibacterial activity. Materials and Methods: Double bond conversion (DC) was measured using Fourier transform infrared spectroscopy (FTIR). Mechanical properties including flexural strength (FS) and flexural modulus (FM) were measured by three-point bending test with bars of 2 mm × 2 mm × 25 mm. Water sorption (WS) and solubility (WSL) were also investigated. Antibacterial activity of obtained polymers against Streptococcus mutans Ingbitt (S. mutans) was tested through direct contact test (DCT). The presence of antibacterial activity due to soluble components was also investigated by agar diffusion test (ADT). Results: All of the IMQ-16 incorporated polymers exhibited improvements in WS and WSL, while maintaining equivalent DC and FS relative to the Bis-GMA/TEGDMA control system. Incorporation of 17% and 20% IMQ-16 into UDMA/SR833s resin reduced the viable counts of S. mutans after incubation on the surface of the materials and produced no inhibition zones around the cured discs in ADT. Conclusions: UDMA/SR833s polymer is a promising resin system to formulate an antibacterial

68 39th Annual Conference of the European Prosthodontic Association resin with equivalent or even higher physical and chemical properties relative to Bis-GMA/TEGDMA formulation. IMQ-16 monomer is capable to endow UDMA/SR833s resin system with significant antibacterial activity.

Poster Presentation No. 21 Conventional vs. computerized determination of the level and inclination of the artificial occlusal plane

Ljiljana Strajnic University of Novi Sad, Faculty of Medicine, Clinic for Dentistry of Vojvodina, Serbia

Purpose: This study evaluated the reliability of the Camper’s plane as a guide to determine the artificial occlusal plane in edentulous subjects and utility of cephalometric parameters for this purpose. Materials and Methods: A total of 60 lateral cephalometric radiographs of subjects with natural dentition and class I skeletal jaw relationship of Serbian nationality from the region of Vojvodina were included in the investigation. Thirty subjects were males, and thirty females, their age range was 20 to 29 years. The obtained values after cephalometric analysis were used as objective parameters in prosthodontic treatment for exact control of the determined artificial occlusal plane in edentulous patients. Cephalometric radiographs of 60 edentulous patients and class I skeletal jaw relationship of Serbian nationality from the region of Vojvodina have been done with models and definitely pre- cised, and marked with lead foils, the level and inclination of artificial occlusal plane according to Camper’s plane. The present study included twenty-five men and thirty-five women, aged between 45 and 78 years. Cephalometric analysis was performed by using “Dr. Ceph” computer software (FYI Technologies, GA, USA). The examined angular cephalometric parameters were: angle between palatal plane and mandibular plane (PP/MP), angle between occlusal plane and palatal plane (OccP/PP); angle between occlusal plane and mandibular plane (Occl/MP). Results: Statistical analysis of data obtained from this study showed statistically significant differences between the values of the inclination of artificial occlusal plane in edentulous patients and the inclination of natural occlusal plane in subjects with natural dentition: PP/MP (p < 0.05), OccP/ PP( p < 0.05), OccP/MP (p < 0.05). Conclusions: Because of his effect on aesthetics, function and denture stability, artificial occlusal plane should be reconstructed as identical as possible to the occlusal plane of missing natural teeth.

Poster Presentation No. 22 Self-perceived chewing function in locator retained mandibular implant overdentures

Sanja Persic, Robert Celic, Dubravka Knezovic-Zlataric, Josip Kranjcic, Asja Celebic University of Zagreb, School of Dental Medicine, Croatia

Purpose: To compare self reported outcomes of a chewing function in two- or four-implant mandibular overdentures (IOD) retained by locators, as well as to assess influence of patients’ age. In spite of abundant literature on oral health related quality of life (OHRQoL) outcomes in different prosthodontic treatment options and various cohorts, the outcomes of a chewing function has not been studied as a single concept. Materials and Methods: Altogether 52 patients with mandibular IODs participated (mean age 66.54 ± 8.6 years). Patients were divided into 2 groups depending on the number of implants (locators) (30 patients with 4 and 22 two implants), age (31 patients older than 60 years; 21 patients younger or equal 60 years), and gender (25 females and 27 males). The one-dimensional Chewing function questionnaire (CFQ) was used to measure patient’s self-perceived chewing function. Summary

69 39th Annual Conference of the European Prosthodontic Association scores of 10 questions were calculated. Statistical analysis comprised descriptive statistics, independent sample t-test and 3 factor ANOVA. Results: Although slightly lower CFQ summary scores (better self assessed chewing function) were registered in the 2 implant IOD group, in females and in patients of higher age no statistically significant differences were found for single factor assessments (p > 0.05). However, the 3 factor ANOVA revealed only one significant effect for the combination of two factors: number of implants and age group (p = 0.028). Conclusions: Older people were more satisfied with 2 locator retained IODs. It seems to be acceptable treatment for completely edentulous elders considering chewing function.

Poster Presentation No. 23 Fatigue resistance of pure titanium wire fabricated by multi-directional forging

Ai Tokue1, H. Miura2, T. Hayakawa3, K. Kimoto4, C. Ohkubo 1Tsurumi University, School of Dental Medicine, Department of Removable Prosthodontics, Tsu- rumi, Yokohama, Kanagawa, Japan 2Toyohashi University of Technology, Department of Mechanical Engineering, Japan 3Tsurumi University, School of Dental Medicine, Department of Dental Engineering, Tsurumi, Yoko- hama, Kanagawa, Japan 4Kanagawa Dental University, Department of Prosthodontics and Oral Rehabilitation, Kanagawa, Japan

Purpose: Fatigue failure of denture clasps decreases the retention of removable partial dentures (RPDs). It is commonly known that the fracture frequency of a titanium wire clasp is higher than that of a cobalt-chromium wire clasp. Application of Multi-directional forging (MDF), which is one of severe plastic deformation methods, to metals and alloys can drastically modify the properties. Especially, MDFing of pure titanium has shown an ease of use and abrasion resistance comparable to that of a titanium alloy. This study evaluated the fatigue resistance of a MDF pure titanium wire and a commercial titanium alloy wire. Materials and Methods: A round (0.9 mm in diameter) wire made with a titanium alloy and an MDF pure titanium wire were used in this study. The clasp specimens (15-mm cantilever) were loaded at the free end by a 20 Hz fatigue-testing apparatus using an electromagnetic force with a constant deflection of 4.0 mm. Fatigue tests were continued until each specimen fractured. The data (n = 5) was analyzed by t-test (α = 0.05). Results: The MDF pure titanium wire showed about 1.4 times greater fatigue resistance as compared to that of the titanium alloy wires; the difference observed between them was significant (p < 0.05). Conclusions: The fatigue resistance of MDF titanium is clearly superior to that of a titanium alloy. MDF of titanium wire clasps would contribute to the long-term use of RPDs.

Poster Presentation No. 24 The accuracy difference between surgical microscope and CBCT to find MB2 canal in me- siobuccal root of maxillary permanent first molar in Malay population

Kais Abdul Majeed, Mustafa Nazih Shaban University IIUM, Kuantan, Pahang, Malaysia

Purpose: To investigate the accuracy difference between the surgical microscope and CBCT to find of extra canal MB2 in maxillary first molar among the Malay population. Materials and Methods: This was an in-vitro cross-sectional study on total of 83 extracted maxillary

70 39th Annual Conference of the European Prosthodontic Association first permanent molars of Malay patients who attended the Polyclinic, Kulliyyah of Dentistry, IIUM. All teeth were cleaned, mounted in a wax box and were sent for a PA radiograph and cone beam computed tomography imaging. Cavity access was performed on all teeth followed by coronal pa- tency under surgical microscope. Results: Out of 83 teeth, 68% were found with MB2 canal. However, prevalence of MB2 canal found in both clinical and radiographic examinations was 68%. Kappa statistic between clinical and radiographic examination was 0.94 (p < 0.001). Conclusions: This study showed that agreement between clinical and radiographic assessments was almost perfect (94%), the treatment can be proceed without expose the patient to extra radiation and it was found the high prevalence of MB2 canal among a sample of Malay population.

Poster Presentation No. 25 Could orthopantomograms be used to determine condylar guidance angles

Jolanta E. Loster, Aneta Wieczorek Jagiellonian University in Kraków, Institute of Dentistry, Collegium Medicum, Department of Pros- thodontics, Poland

Purpose: Different clinical procedures are used to obtain numerical data on the condylar guidance angle. A method using orthopantomogram radiographic images (OPG) has been described in the literature. The aim of the present study was to verify the recommendation of this method in clinical use. Materials and Methods: One panoramic radiographic image was randomly chosen from a group of 191 images from individuals who were free of the signs and symptoms of temporomandibular disorders and possessed intact dentition. The digital image was converted to analogue and printed. The study involved 21 dentists, who were asked to position four dots on both sides of the image (the orbitale and porion, and the most superior and the most inferior points of the jaw’s articular surface). The marked images were then scanned. Using computer software, the points were connected with lines A and B on both sides. To evaluate the accuracy of the lines, the equation of the straight line was calculated and their slopes compared. The condylar guidance angle between lines A and B was calculated. Results: The spread of the results for the condylar guidance angle on the right side was 30 degrees; on the left side, it was more than 40 degrees. The SD for the slope of line A was 0.01 on both sides. The slope value of line B varied from 0.25 to 0.34. Conclusions: The use of OPG to obtain the condylar guidance angle is not recommended in clinical use.

Poster Presentation No. 26 The effect of implant diameter and length on stress distribution for single implant treatment using 3D FEM analysis

Akikazu Shinya, Soichi Kuroda, Harunori Gomi Nippon Dental University, Fujimi, Chiyoda-ku, Tokyo, Japan

Purpose: The aim of this simulation was to evaluate the effects of implant diameter and length on the stress exerted on peri-implant bone, to investigate the usefulness of virtual implant. Materials and Methods: Three-dimensional (3D) finite element model of the mandibular bone was created from 3D x-ray CT scan images of healthy adult male. Simulating the clinical scenario of implant therapy at the mandibular first molar region, virtual extraction of this tooth was performed on the model and 12 different diameters and lengths experimental designed implants were virtually

71 39th Annual Conference of the European Prosthodontic Association placed in order to carry out an equivalent stress. Results: High stress distribution was found on the surfaces of the buccal and lingual implant bone adjacent to the sides of the neck in all the implants. The highest stress value was approximately 6.0 MPa with implant diameter of 3.8 mm, approx. 4.5 MPa with implant diameter of 4.3 mm, and approx. 3.2 MPa with implant diameter of 6.0 mm. Conclusions: The stress on the implant bone was found to decrease with increasing mainly diameter of the implant.

Poster Presentation No. 27 Relationship between muscle and oral function in Japanese community-dwelling elderly

Miwa Matsuyama, Tomoya Omura, Akari Watanabe, Riko Kobayashi Tokushima University, Kuramoto-cho, Tokushima-shi, Japan

Purpose: The aim of the present study was to survey skeletal muscle status, oral function, and the relationship between the two in community-dwelling elderly people. Materials and Methods: Twenty-four community-dwelling elderly were assessed using following parameters: Skeletal muscle index (SMI), grasping power, walking speed, jaw-opening force, occlusal force, the gum-chewing test, maximum voluntary tongue pressure, RSST, MWST and diadochokinesis. Correlations between parameters were analyzed using Spearman’s correlation coefficient. The subjects were divided into two groups according to standards for grasping force: healthy and muscle weakness. Additionally, subjects were divided into two groups based on Eichner’s classification. Parameters were statistically compared between the two groups using the Mann-Whitney U test. Results: There were statistical relationships between SMI and grasping force (r = 0.455, p < 0.05), SMI and jaw-opening force (r = 0.578, p < 0.01), and grasping force and jaw-opening force (r = 0.640, p < 0.01). In the weak muscle group, jaw-opening force and the number of diadochokinesis were larger than the corresponding values in the healthy group (p < 0.01 for both comparisons). For patients wearing a prosthesis in the non-occlusal support group, RSST and MWST results were better than the corresponding values for patients in the occlusal support group (p < 0.05 for both comparisons). It is reasonable that an overall decrease in muscle mass would evoke decreases in muscle strength in both the extremities and the jaw-opening muscles. Conclusions: We confirmed significant relationships between skeletal muscle mass, skeletal muscle strength, and oral function in Japanese community-dwelling elderly.

Poster Presentation No. 28 Analysis of mandibular movements in patients with temporomandibular disorder

Daina Spule, Evija Nikitina, Una Soboleva Riga Stradins University, Stomatology Institute, Latvia

Purpose: The aim of this study was to analyse a restricted movements of mandible and the mandibular pathway association with temporomandibular joint (TMJ) bone structural changes in temporomandibular disorder (TMD) patients with clicking sounds of temporomandibular joint. Materials and Methods: The study involved 30 TMD patients (mean age 31.06 years, 86 % women) with clicking sounds of the TMJ. The TMJ border movements and the mandibular pathway during maximal opening was measured and recorded with an ultrasonic instrument Arcus Digma (KaVo). The TMJ morphology was evaluated with cone beam computed tomography (iCAT New Genera- tion, Imaging Sciences International, Inc. Hatfield, PA, USA). Presence of structural changes in bone structures of the joint were assessed in coronary and sagital plane, based on the system

72 39th Annual Conference of the European Prosthodontic Association worked out by Dworkin (1992) for assessment of changes in temporomandibular joint (RDC/TMD). Data were analysed using descriptive and analytical statistical methods. Statistical significance was tested using Fisher test. P value less than 0.05 was chosen as a significance level. Results: Limited mouth opening showed 36.7% of cases, restricted movement to the right was in 6.7% of cases, restricted movement to the left was in 16.7% of cases. TMJ bone changes were observed in 28.5% of cases. 27.2% of this subgroup showed limited mouth opening while 26.3% – unlimited mouth opening. 50% of all cases showed only deviation during mouth opening movement without restriction. Conclusions: At the current stage of this study based on collected data, it can be concluded that there is no statistically significant relationship between the maximum border movement limits and the TMJ bone structural changes. Most common feature is the mandibular deviation during mouth opening.

Poster Presentation No. 29 Comparing different kinds of edentulous patients’ static and dynamic muscle activation (M. Masseter, M. Temporalis anterior) before and after prosthetic rehabilitation with electromyography

Mahmut Sertac Ozdogan Yildirim Beyazit University, Ankara, Turkey

Purpose: This study is performed in order to evaluate the changes in masseter and anterior temporalis muscles activity after using dentures at patients with partial dentures and patients with complete dentures. Materials and Methods: For this purpose after making partial removable dentures for single sided and double sided edentulous patients and complete prosthesis for the patients with old complete prosthesis applied for a period of 1 month on 36 individuals whose mean age was 56.8 ± 8.5 years, at patients with partial dentures, 54.1 ± 5.7 years, at patients with complete dentures, 37.1 ± 5.7 years at subjects with natural dentitions and electromyographic (EMG) records were taken both before using removable partial dentures and at patients with old complete dentures, first day, first week, first month of the application from each individual. Muscle activation values of single sided and double sided prosthesis and complete prosthesis at the first month were compared with natural dentition during four jaw movements (chewing, maximal clench, swallowing, and rest). Muscle activation changes of M. Massetericus and M. Temporalis anterior of patients with single sided and double sided prosthesis and complete prosthesis were evaluated during 1 month period. One-way ANOVA, Paired simple t-test, Kruskal-Wallis H test and Mann-Whitney U test used for the evaluation of the measurements. Results: The muscle activity recordings taken at first month from M. Massetericus and M. Tem- poralis anterior from patients with partial dentures and patients with complete dentures were significantly lower from patients with natural dentition. As a response to prosthetic rehabilitation, at chewing and maximal clench, at the first day of the denture use, the rise of muscle activation from the first day abate to the first month were viewed. But this didn’t get to the values which were taken before the denture use. Conclusions: As it is known, muscles amplitude variability is related with muscles neural control. At first day the amplitudes are high, as during chewing and maximum clench has more motor unit activity. That is why at first day of the prosthetics, patients managed to use new prosthesis. This can be taught patients managed to adaptation to new prosthesis and muscle activity gets higher. From first day to the first month muscle activity gets lower this maybe because of adaptation to the new prosthesis. First month values are higher than before the prosthetic rehabilitation and the reason can be adaptation to the normal functions.

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Poster Presentation No. 30 Effect of laser treatment on bond strength of bleached enamel

Müjde Sevimay1, Ceyda Akin2, Ozgun Yusuf Ozyilmaz3, Neslihan Cokuk4 1Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Campus Konya, Turkey 2Necmettin Erbakan University, Faculty of Dentistry, Department of Prosthodontics, Konya, Turkey 3Istanbul Medipol University, Faculty of Dentistry, Department of Prosthodontics, Istanbul, Turkey 4Yuzuncuyil University, Faculty of Dentistry, Department of Prosthodontics, Van, Turkey

Purpose: The aim of this study was to evaluate the effect of surface treatment with Er:YAG and Diode lasers on resin cement bond strength to recently bleached enamel. Materials and Methods: 72 human central incisors were divided into two groups: group O: bleached with Opalescence Endo and group W: bleached with Whiteness HP. Each group was divided into three subgroups: subgroup C: without laser treatment (OC, WC); subgroup Er: irradiation with Er:YAG laser (OE, WE); subgroup D: irradiation with Diode laser (OD, WD). After bleaching treatments atomic force microscopy was carried out and then resin cement Panavia cylinders of 3 mm × 3 mm (Panavia F 2.0, Kuraray Co. Ltd., Japan) were bonded to the enamel surfaces. All specimens were subjected to shear bond strength test after 24 h of storage in water. The shear bond strength was measured using a Universal testing machine (TSTM 02500, Elista Ltd. Şti., Turkey) at a 0.5 mm/min crosshead speed. The data were analyzed statistically with ANOVA followed by Tukey’s test (p < 0.05). Results: Two way ANOVA test analysis showed there was significant differences between laser groups but no significant differences between the bleaching agents and bleaching agents and lasers. There were no significant differences between the WC (28.29 MPa) and OC groups (26.70 MPa). OD group was showed the lowest shear bond strength (17.99 MPa) with statistical difference of WE (23.20 MPa), WC (28.29 MPa), and OC (26.70 MPa). Significant morphological alterations were observed in all groups. Conclusions: The results suggested that following the bleaching treatments, the use of Er:YAG laser may provide higher bond strengths than Diode laser.

Poster Presentation No. 31 Correlation between the nose width, mouth width and the widths of maxillary anterior teeth

Gloria Staka, Venera Bimbashi, Flurije Asllani Hoxha Republic of Kosovo

Purpose: It is difficult to determine the width of the maxillary anterior teeth for an edentulous patient when pre-extraction records are not available. The purpose of this study was to evaluate the relationship between nose width (NW), mouth width (MW) and two other measurements of the maxillary anterior teeth (intercanine cusp tip distance – ICTD and width of maxillary anterior teeth – WMAT). Materials and Methods: One hundred and sixty Kosovo Albanian dental students at the Univer- sity of Prishtina, Dental School were evaluated. The sample comprised 80 males and 80 females ranging in age from 19 to 25 years. The anthropometric measurements of the nose width and mouth width were recorded directly on the subjects while intercanine cusp tip distance and width of maxillary anterior teeth were measured on the dental casts using an electronic digital calliper with accuracy of 0.01 mm (Digital calliper Boss Hamburg – Germany). Basic statistical parameters and Pearson correlation coefficient were calculated. Results: There was no significant correlation between nose width, mouth width and two other measurements of maxillary anterior teeth (ICTD and WMAT) in male subjects. Significant correlation (r = 0.32; p < 0.01) was found in female subjects between mouth width and width of maxillary anterior teeth. Conclusions: Nose width and mouth width would not be reliable guides for determine the width of artificial anterior teeth for complete dentures. 74 39th Annual Conference of the European Prosthodontic Association

Poster Presentation No.32 Marginal and internal fit of CAD/CAM ceramic crowns fabricated from different ceramic blocks

Senem Ünver, Merve Bankoğlu Güngör, Aylin Doğan, Bilge Turhan Bal, Seçil Karakoca Nemli Gazi University, Faculty of Dentistry, Turkey

Purpose: The purpose of this study was to evaluate marginal and internal adaptation of CAD/CAM crowns made from 7 different materials. Materials and Methods: Crown restorations (n = 10) were fabricated from seven CAD/CAM blocks (IPS e.max, Lava Ultimate, inCoris TZI, inCoris ZI, Vita Suprinity, Vita Enamic, GC Cera Smart). In order to document the marginal and the internal discrepancies, silicone replicas were fabricated. The crowns were filled with a light body silicone and placed on the abutment teeth. The thin silicone layer represented the gap width between the inner surface of the crown and the surface of the abutment tooth. After setting of the light body silicone, the crown was removed from the abutment. The thin green-coloured silicone film in the abutment crowns was stabilized by injecting a heavy purple-coloured body silicone. The replicas were removed and segmented with a blade. The green- coloured silicone layer, which represented the discrepancy between the die and the inner surface of the restoration, was examined at 50x magnification using a light microscope with digital camera. At each cross-section, four landmarks were measured. A one-way analysis of variance (ANOVA) was used to compare data (p = 0.05). Results: One-way ANOVA showed significant differences between materials for marginal fit (p < 0.05) and internal fit (p < 0.05). However, the measured values of discrepancies were low. Conclusions: All materials showed low marginal and internal discrepancies and were therefore considered clinically acceptable. The CAD/CAM crown restorations fabricated from different blocks are precisely adapted on the abutment teeth.

Poster Presentation No. 33 Effect of different veneering techniques on the fracture strength of ceramics

Turk Ayse Gozde1, Mubin Ulusoy2, Mert Yuce2, Hakan Akin2 1University of Ege, School of Dentistry, Department of Prosthodontics, Turkey 2Cumhuriyet University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: To determine whether the fracture strengths and failure types differed between metal and zirconia frameworks veneered with pressable or layering ceramics. Materials and Methods: A phantom molar tooth was prepared and duplicated in 40 cobalt-chromium abutments. Twenty metal (IPS d.SIGN 15, Ivoclar Vivadent, Schaan, Liechtenstein) and 20 zirconia (IPS e.max ZirCAD, Ivoclar) frameworks were fabricated on the abutments. Each framework group was randomly divided into 2 subgroups according to the veneering material: pressable and layering ceramics (n = 10). Forty molar crowns were fabricated, cemented onto the corresponding abutments and then thermocycled (5–55 ˚C, 10,000 cycles). A load was applied in a universal testing machine until a fracture occurred on the crowns. In addition, failure types were examined using a stereomicroscope. Fracture load data were analyzed using one-way ANOVA and Tukey HSD post- hoc tests at a significance level of 0.05. Results: The highest strength value was seen in metal-pressable (MP) group, whereas zirconia- pressable (ZP) group exhibited the lowest one. Moreover, group MP showed significantly higher fracture loads than group ZP (p = 0.015) and zirconia-layering (ZL) (p = 0.038) group. No significant difference in fracture strength was detected between groups MP and ML, and groups ZP and ZL (p > 0.05). Predominant fracture types were cohesive for metal groups and adhesive for zirconia groups. Conclusions: Fracture strength of a restoration with a metal or a zirconia framework was independ-

75 39th Annual Conference of the European Prosthodontic Association ent of the veneering techniques. However, the pressing technique over metal frameworks resisted significantly higher fracture loads than zirconia frameworks.

Poster Presentation No. 34 Inaccuracies generated during digital impression making in implant prosthodontics

Panagiotis Galanopoulos, Stefania Grous, Stavros Pelekanos Greece

Purpose: The aim of this poster presentation is to demonstrate the problems occurring during digital impression making procedures in implant prosthodontics generating prosthetic appliances of questionable accuracy. Inaccurate prosthesis may lead to biological complications (mucositis, peri-implantitis) and to mechanical complications (screw loosening, fracture of the prosthesis or of an implant component). Materials and Methods: There are two alternatives for digital impression making; A. The direct (intraoral) data capturing technique. An intraoral scanner is used to collect optical data directly from the patient’s mouth. These data are then used to create a 3D model through software compatible with the scanner. B. The indirect (extraoral) data technique using a scanner that captures the optical data from an existing master cast, which are then used to create a 3D model. Most of the oral scanners have problems in scanning a reflective, shiny surface. This is the reason why some manufacturers provide a specific powder to apply on the area to be scanned. In various situations specific scanbodies are also required. Results: The problems that might occur during digital impression making in implant cases could be due to: Inexperience; Failure to create a final scan of the scanbodies; Misalignment of the photos during the stitching phase; Deformation of the scanbodies; Positioning of the scanbodies. Conclusions: The evolution of the digital dental technology has been impressive in the last decade. The latest studies underline the improvements needed to be made so that the conventional impression making can be replaced in daily clinical practice.

Poster Presentation No. 35 Bone augmentation and implant prosthetic rehabilitation versus partial removable dentures

Sirbu Dumitru, Oleg Solomon, Mihail Mostovei, Vadim Popovici, Stanislav Strisca State University of Medicine and Pharmacy “N. Testemitanu”, Republic of Moldova

Purpose: Evaluation of the methods of patients’ rehabilitation that have insufficient bone support by comparative analysis of conventional and implant prosthetic methods with preliminary bone augmentation. Materials and Methods: In the study were included 24 patients with alveolar bone defects of different aetiology who needed prosthetic rehabilitation. Patients were divided in two groups: The first group consisted of 9 patients (mean age 38 ± 2.77 years) who were rehabilitated with fixed implant supported metal-ceramic prostheses after bone augmentation. The second group consisted of 15 patients (mean age 54.8 ± 2.3 years) who were rehabilitated with partial removable prosthesis. In the second group, 10 patients were rehabilitated on both arches and 5 patients on one arch. Pa- tients were given a questionnaire of satisfaction consisted of 20 questions. Results: In the first group, after augmentation procedures, it was possible to insert implants of standard size and manufacture fixed metal-ceramic prostheses type FP1, FP2 and FP3 (according to Carl E. Misch classification). After 12 months there was 0.5 ± 0.08 mm bone resorption mesially and 0.41 ± 0.06 mm distally. There have not been noticed any pathological signs in peri-implant soft tissues. In 30% of cases was noted the loss of prosthetic stability after 12 months.

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Conclusions: Despite of long rehabilitation period, multiple surgical procedures and higher price needed for implant prosthetic rehabilitation with preliminary bone augmentation, this method is often required by patients due to its advantages over the rehabilitation with removable prosthesis.

Poster Presentation No. 36 The efficiency of different polishing systems on the surface roughness of full-contour CAD/ CAM ceramics

Monika Mackeviciute, Simonas Dubonis Vilnius University, Faculty of Medicine, Institute of Dentistry, Lithuania

Purpose: To evaluate the efficiency of different chair-side polishing systems on the surface roughness of full-contour CAD/CAM ceramics after clinically simulated adjustment. Materials and Methods: Seventy-five square-shaped specimens (sides 10 mm) of different CAD/ CAM ceramics were fabricated: Kerox (n = 20), Doceram (n = 15), Metoxit (n = 20), VITA SUPRIN- ITY (n = 10) and VITA ENAMIC (n = 10) (5 groups). The specimens were sintered, polished with technical polishers in dental laboratory. Simulated clinical grinding was performed under water coolant for 15 s and 2 N pressure. NTI diamonds burs (red and yellow) were used sequentially. The surfaces were polished under water coolant for 20 s and 2 N pressure with different chair-side polishing systems: CeraMaster (SHOFU), CeraGloss (EDENTA), Set 4622 (KOMET), VITA SU- PRINITY Polishing Set (clinical), VITA ENAMICs Polishing Set (clinical), DirectDia (SHOFU) and DiaPolisher (GC) polishing pastes. To remove residues from the surfaces, the test specimens were placed in Ultra-sound appliance with distilled water at 35 °C for 10 min. Before and after clinically simulated adjustment and polishing, the surface roughness (Ra average) (μm) of each ceramic was measured with a 3-dimensional (3D) optical profilometer (3 times per specimen) and scanning electron microscope (SEM) (magnification 500, 1000x). The data obtained were statistically analyzed by SPPS (version 20.0): T-test, one-way ANOVA, correlations. Results: The surface roughness of Metoxit (Ra average = 3.062 ± 0.638) zirconia after clinical adjustment and polishing was significantly higher than that of Doceram (Ra average = 2.509 ± 0.577) or Kerox (Ra average = 2.40 ± 0.527) (p = 0.002). All zirconia ceramics demonstrated similar surface roughness after polishing in dental laboratory. There was no statistical significance among the groups after polishing in dental laboratory or chair-side polishing. The use of different clinical polishing systems exhibited no significance on surface roughness within ceramics or polishing systems groups. Conclusions: The surface roughness before and after clinical adjustment and polishing with different chair-side polishing systems is comparable. The best results in chair-side polishing are achieved by using Kerox and Doceram zirconia.

Poster Presentation No. 37 The effect of prosthodontic treatment on mastication predominance

Kyosuke Oki Japan

Purpose: The aim of the present study was to investigate the effect of prosthodontic treatment on mastication predominance in patients with unilateral posterior missing teeth using the objective assessment of masseter muscle electromyographic (EMG) activity. Materials and Methods: The sample consisted of 56 patients with unilateral posterior missing teeth who received prosthodontic treatments: removable partial denture (RPD group) or fixed implant prosthesis (Implant group). EMG activities were recorded from the bilateral masseter muscles while

77 39th Annual Conference of the European Prosthodontic Association subjects were asked to chew chewing gum freely for 40 seconds. The assessment of mastication predominance was conducted before and after prosthodontic treatments. The chewing side (right or left) was judged by the level of root mean square EMG amplitude. The mastication predominance was then objectively assessed by mastication predominant index (MPI): the proportion in the number of the difference between the right and left side strokes against the number of total strokes. The MPI was analyzed in terms of period (before and after prosthodontic treatments) and treatment option (RPD group and Implant group). Results: There was a significant difference in the MPI before and after prosthodontic treatments (p < 0.05). Regarding the treatment option, the amount of change in MPI between RPD group and Implant group was significantly different (p < 0.05). Conclusions: The obtained results suggested that prosthodontic treatment could have an influence on the improvement of masticatory predominance. It was also suggested that the implant prosthodontic treatment might be more effective than the removable partial denture treatment in terms of mastication predominance.

Poster Presentation No. 38 The effect of different shades of resin cements and composite thickness on the final colour of veneers

Esra Cengiz, Sevcan Kurtulmus-Yilmaz, Oguz Ozan, İzgen Hacıogulları, Nuran Ulusoy Near East University, Faculty of Dentistry, Turkey

Purpose: The aim of the study was to evaluate the effect of different shades of resin cements on the final colour of 2 different thicknesses of 2 different composite resins. Materials and Methods: A total of 112 discs were fabricated from A2 colour of each resin composite (Clearfil Majesty Esthetic, Kuraray; AELITE Aesthetic Enamel, Bisco) with 2 different thicknesses (0.5 mm and 1 mm). Baseline CIE L* a* b* colour coordinates were measured with spectrophotometer (VITA Easyshade Compact), and then composite discs were divided into 4 groups according to the shades (A1, A3, transparent and opaque) of resin cements (Variolink II, Ivoclar Vivadent) (n = 7). After luting the resin cements to the composite discs, colour measurements were repeated and colour differences (ΔE) were calculated. Data were statistically analyzed with one-way ANOVA and Tukey HSD test. Results: The results of the study showed that the opaque shade had significantly increased ΔE values when compared with the other shades (A1, A3, transparent) (p < 0.05) whereas no significant difference was found among A1, A3 and transparent shades for all groups (p > 0.05). For A1 and transparent shades in 0.5 mm thickness, ΔE values of AELITE were higher compared to Clearfil Majesty Esthetic. There is no significant difference between 2 thicknesses for both composite resins in terms of ΔE values. Conclusions: The shade of the resin cement influenced the resulting colour of composite laminate restorations, whereas the thickness of the composite resin had no effect on the final colour of veneers.

Poster Presentation No. 39 Development of a continuous cingulum rest using an adhesive composite resin

Risa Matsuda, Daisuke Kurihara, Hidekazu Osada, Shigeru Hanatani, Chikahiro Ohkubo Tsurumi University, School of Dental Medicine, Department of Removable Prosthodontics, Japan

Purpose: The continuous clasp in a removable partial denture (RPD) has been constructed before more than 100 years. It was placed just incisally of the lingual eminence of the tooth and has the

78 39th Annual Conference of the European Prosthodontic Association combined advantages of providing bracing and assisting good gingival hygiene. For more tooth support from incisors, continuous cingulum rest seats have been developed that use adhesive composite resin. Materials and Methods: Cingulum rest seats have been affixed using an adhesive composite resin as the floor of the rest seat on the lingual surface of a mandibular incisor or canine. After a definitive impression was made, the following laboratory procedures are conventionally carried out: 1) A refractory cast is made from the original master cast after relief and blockout; 2) The pattern of the RPD framework is waxed freehand, especially, a continuous cingulum rest using ready-made pattern forms; 3) After the sprued pattern is invested, the RPD framework is conventionally cast and polished. The cast framework is evaluated intraorally, and a sufficiently accurate adaptation and design identical to the continuous cingulum rest are revealed. Results: Advantages include: 1) Maximum support and bracing can be provided from the incisors; 2) More rigidity can be obtained with a lingual bur; 3) Tooth and soft tissue surfaces covered can be smaller than the lingual plate; 4) Adding an artificial tooth to the framework is easy. Conclusions: By improving the adhesion of composite resin, a continuous cingulum rest can be provided for obtaining greater support from incisors than with a Kennedy bar.

Poster Presentation No. 40 Association between asymmetry index and distribution of occlusal contacts in young adults

Aneta Wieczorek1, Jolanta Loster 1, Bartlomiej W. Loster2, Teresa Sierpińska, Maria Gołębiewska4 1Jagiellonian University, Institute of Dentistry, Department of Dental Prosthetics, Kraków, Poland 2Jagiellonian University, Institute of Dentistry, Department of Orthodontics, Kraków, Poland 3Medical University of Białystok, Department of Dental Technique, Poland 4Medical University of Białystok, Department of Prosthetic Dentistry, Poland

Purpose: The aim of the study was to determine the association between the asymmetry of the masticatory muscles (LTA, RTA, LMM, and RMM), sex, and occlusal classes and occlusal contacts in asymptomatic young adults. Materials and Methods: One hundred and forty-four Caucasian volunteers (96 females, 48 males) aged eighteen years participated. The exclusion criteria included transversal malocclusion, any periodontal disease, caries, bruxism, neuropathic conditions, maxillofacial disease, and psychological disorders. A surface electromyography (sEMG) recording with an 8-channel BioEMG III BioPAK Measurement System Electromyograph (BioResearch, Inc., Milwaukee, WI, USA) was used to quantify the degree of asymmetry in the activity of the masticatory muscles, as well as to determine the balance between masseter and temporary anterior muscles. In order to determine the degree of symmetry of the maximal occlusion contact, occlusal contact points were analyzed using a T-scan III evolution 7.01 device (Tekscan, Inc., South Boston, MA, USA). Occlusal classes were graded by means of an approach based on plaster study models. Results: Our findings show that the asymmetry index shows the predominance of the right-side muscles across sex and occlusal class and distribution of occlusal contacts on left side. Conclusions: Presented results are concerning asymptomatic young adults.

Poster Presentation No. 41 Evaluation of CAD/CAM denture, “Whole You” milled denture

Maki Sato, Daisuke Kurihara, Ai Tokue, Tomoya Terauchi, Chikahiro Ohkubo Tsurumi University, School of Dental Medicine, Department of Removable Prothodontics, Japan

Purpose: Recently, computer-aided designed (CAD), computer-aided manufacturing (CAM) den-

79 39th Annual Conference of the European Prosthodontic Association ture was developed by Whole You, Inc., Mitsui Chemicals Group. They use the DENTCA tray system for impression taking, which made the denture design by CAD. Then from the CAD denture, data denture, milled denture will be produced by CAM. The performance of this CAD/CAM denture was evaluated. Materials and Methods: Using DENTCA trays and hard and medium flow silicone impression materials, definitive impressions of maxillary and mandibular edentulous jaws are made with a double impression technique. Both impressions are cut and separated; maxillomandibular registration and Gothic arch tracing are performed using the anterior portions of impressions. They are scanned, and the complete dentures are designed and milled from an acrylic resin block (developed by Mitsui Chemicals Group). The dentures are thinly coated (approximately 10 μm) with hydrophilic coating material (developed by Mitsui Chemicals Group), and the complete dentures are delivered during a second visit. Results: Because the denture base is milled from the acrylic block by precise CAD/CAM technology, the palatal plate thickness of the CAD/CAM dentures can be controlled to be thinner than the conventional dentures. The thickness is approximately 1 mm. And the coating material makes easier to remove the stain on both polished and impression surfaces. Conclusions: Complete denture fabrication in two visits can be confirmed by using the DENTCA tray system and milling denture production process. The coating material is also effective for the stains to be removed easily.

Poster Presentation No. 42 Identifying colour changes of denture base acrylics on scanned images

Panagiotis Zoidis, P. Lagouvardos, G. Polyzois National and Kapodistrian University of Athens, Dental School, Greece

Presentation was cancelled.

Poster Presentation No. 43 Hard and soft tissue reactions to different attachment systems in implant retained overdentures

Nader Abolfazli1, Fariba Saleh Saber2 1Tabriz University of Medical Science, Dental Faculty, Periodontics Department, Iran 2Tabriz University of Medical Science, Dental Faculty, Prosthodontics Department, Iran

Purpose: Although implants have offered a great service to partially edentulous patients, the most dramatic changes have been achieved in bone and soft tissues of atrophic mandibles and/or maxillae. The purpose of this article is to discuss the potential effect of the different attachments used routinely in implant-retained overdentures on soft and hard tissue. Materials and Methods: Relevant articles were screened and selected based on a MEDLINE search limited to English-language articles published from 1995 to the present with regard to retention of different attachment systems available in the dental market. Selection criteria were done based on previously published articles in the literature. Results: 80 relevant articles were found after an initial search from databases mentioned before. Following the title, abstract and full text level eliminations, total of seventeen papers was selected for critical analysis and appraisal. Conclusions: The results of this review indicate that the marginal bone loss cannot be related to the use of different attachment systems and peri-implant soft tissue health is not affected by either

80 39th Annual Conference of the European Prosthodontic Association ball or bar attachments. It is believed that the direction of occlusal forces is more important than the connection of the implants. A mean marginal bone loss of 0.3 mm within the first year at implants with bars and clips or Ceka attachments was recorded. In the maxillae when O-rings were used as an attachment, rapid bone loss around fixtures has been documented too.

Poster Presentation No. 44 Attachment systems and retention of implant supported overdentures

Fariba Saleh Saber1, Nader Abolfazli2 1Tabriz University of Medical Science, Dental Faculty, Prosthodontics Department, Iran 2Tabriz University of Medical Science, Dental Faculty, Periodontics Department, Iran

Purpose: Large number of manufacturers around the world provided much different design of attachments. The purpose of this review is to evaluate and compare the retention of implant-retained overdentures with different routinely used attachment systems. Materials and Methods: Relevant articles were screened and selected based on a MEDLINE search limited to English-language articles published from 1995 to the present with regard to retention of different attachment systems available in the dental market. Selection criteria were done based on previously published articles in the literature. Results: 80 relevant articles were found after an initial search from databases mentioned before. Following the title, abstract and full text level eliminations, total of eight papers was selected for critical analysis and appraisal. Conclusions: The results of this review suggest that the retention appear to have an effect on long- term success and patient satisfaction and seems to decrease over time especially for the most retentive designs. Bars and clips seem to be more retentive. They can be selected when a high degree of retention is required such as extremely resorbed ridges without tissue undercuts. The retentive forces of most attachment systems are in the range of about 20 N. The least retentive attachments are the magnets. Some investigators suggest that these should be used in cases of bruxism. The complex movements in function can clinically lead to plastic deformation of the matrix portion, resulting in a reduction of retention or fractures of the clip.

Poster Presentation No. 45 Evaluating the short term colour stability of resin cements

Numan Tatar, Çağrı Ural, İbrahim Duran, Özgür Özturk, İsmail Kaya, İdris Kavut Ondokuz Mayis University, Faculty of Dentistry, Samsun, Turkey

Purpose: Colour changes of the luting material can become clinically visible affecting the aesthetic appearance of translucent all-ceramic restorations. The aim of this in vitro study was to evaluate the early period of colour stability of light and dual-cured resin cements and its effect on the final shade of the all-ceramics. Materials and Methods: Three different resin cements in both light and dual-cure forms were included in the study (Rely X/3M, NX3/ Kerr, Variolink/Ivoclar Vivadent). All resin cement prepared 1 mm diameter and 0.5 thicknesses with using acetalpolyoxymethylene (Derlin) mould. Curing was performed according to ISO standards with a calibrated LED curing light. After curing 0.7 mm thickness feldspathic porcelain placed on the resin cement and colour measurements were determined using spectrophotometer. Samples were stored 24 h in 37 ˚C distilled water at dark and then colour measurements determined again. Changes in colour (ΔE) were obtained using the CIE L* a* b* system. The results were submitted to one-way ANOVA, Tukey HSD test (α = 5%). Results: The ΔE values were listed under clinically acceptable limit of 3.3, except one dual-cure

81 39th Annual Conference of the European Prosthodontic Association resin cement group. Although the light-cure resin cement test specimens showed less than 1.0 ΔE values, dual cure resin cement test specimens showed ΔE values between 1.11 and 5.54. Conclusions: The aesthetic performance of all ceramic restorations can be affected by the colour of the resin cement. Dual-cured resin cements presented significantly more colour changes in short term period, however, light cure resin cements showed clinically acceptable ΔE values.

Poster Presentation No. 46 Examination of the antifungal activity of nystatin mixed into a soft relining

Zsófia Muzsek, Béla Kocsis, Sándor Nagy, Szilárd Pál, Márta Radnai University of Pécs, Hungary

Purpose: The aim of the study was to examine the dissolution and the antifungal activity of medication incorporated into soft relining material applying conditions similar to the oral cavity. Materials and Methods: Sample discs were prepared using denture base material with a diameter of 10 mm and a thickness of 1.5 mm. After mixing 10% Nystatin (group 1, N = 6) and 10% Nystatin and Eudragit® NE30D (Evonik Industries AG, Germany) (group 2, N = 6) to a soft relining material (UfiGel® VOCO GmbH, Germany), it was applied to one side of the acrylic discs in a thickness of 1.5 mm. Control discs were prepared without any agents (n = 3). The discs were immersed in 150 ml of artificial saliva, separated, kept at room temperature and the dissolution of the antifungal agent was measured for three months with spectrophotometer. Microbiological examination and agar diffusion tests were carried out immediately after the sample preparation and after three months, while the bioautography was completed after three months of immersion. Results: The dissolution rate of Nystatin was higher in group 2 in the first month; later in group 1 and group 2 followed a similar pattern according to the spectrophotometric examination. Agar diffusion test, carried out with the discs after three months immersed in the saliva did not reveal antifungal effect. The bioautographic analysis confirmed the results of the spectrophotometric examination. Conclusions: The results provided evidence for the dissolution of Nystatin that was effective at start, however after three months there was no effective antifungal agent left in the soft relining material.

Poster Presentation No. 47 Micro-shear bond strength of resin cements to Er,Cr:YSGG laser and acid etched enamel

Nuran Ulusoy, Laden Gulec, Fjolla Koshi, Izgen Hacıogulları, Esra Cengiz Near East University, Faculty of Dentistry, Turkey

Purpose: The aim of this study was to evaluate the micro-shear bond strength (MSBS) of 2 different resin cements to enamel etched with phosphoric acid, Er,Cr:YSGG laser irradiation, or Er,Cr:YSGG laser irradiation followed by acid etching. Materials and Methods: 24 caries-free molars were sectioned vertically and the flat buccal surfaces were used. 12 enamel discs for each of the resin cements (Panavia F 2.0 and Variolink N) were randomly divided to 3 subgroups according to the surface pre-treatment methods: 1) 37% phosphoric acid application for 20 seconds; 2) Er,Cr:YSGG laser (Waterlase MD, Biolase) irradiation at an energy level of 2 W, a repetition rate of 20 Hz with 55% water and 65% air irradiation for 10 seconds; 3) Er,Cr:YSGG laser irradiation for 10 seconds followed by 20 seconds of 37% phosphoric acid etching. 3 cylinders of resin cements were bonded to each enamel surface and MSBS was determined in a universal testing device at a crosshead speed of 1 mm/min. One-way analysis of variance and Tukey post-hoc tests were used to analyze the MSBS values. Results: Panavia showed significantly higher MSBS values than Variolink (p < 0.05) for allthe tested surface pre-treatment methods. Panavia showed the highest MSBS when the enamel was

82 39th Annual Conference of the European Prosthodontic Association treated by laser irradiation and acid etching. Conclusions: The combination of laser irradiation and acid etching exhibited higher MSBS values to enamel than the use of acid or laser irradiation alone in the bonding of resin cements, holding the potential to become a suitable method for conditioning enamel surface.

Poster Presentation No. 48 Efficacy of various pre-treatments on the bond strength of denture teeth to denture base resins

Omer Kırmalı, Ozlem Ustun, Tuba Battal Akdeniz University, Faculty of Dentistry, Turkey

Purpose: To evaluate the effect of different pre-treatments such as sandblasting, grounding with a carbide bur and Er,Cr:YSGG laser irradiation of different intensities (1 to 4 W) in the ridge lap area of acrylic resin denture teeth on the shear bond strength (SBS) to heat-polymerized polymethyl- methacrylate (PMMA) denture base resin. Materials and Methods: A total of 70 central incisor denture teeth were used in this study and were divided into 7 groups as; control group (no surface treatment), grounded with a tungsten carbide bur, sandblasted with 120 µm Al2O3 particles and Er,Cr:YSGG laser irradiated with different intensities (1 to 4 W). All specimens then were subjected to SBS test at a crosshead speed of 1 mm/ min until fracture. Data were analyzed with one-way ANOVA and post hoc Tukey-Kramer multiple comparisons tests (p = 0.05). Results: Similar SBS values were obtained after air abrasion, grounding with a carbide bur and irradiation by an Er,Cr:YSGG laser at 1 to 4 W and no significant differences among surface treatments and control group (p < 0.05). Conclusions: Bond strength of acrylic denture teeth to (PMMA) denture base material is independent of the surface pre-treatments with both Er,Cr:YSGG laser, sandblasting and grounding with a carbide bur. In addition, all surface treatments provided similar bond between the acrylic denture base and teeth.

Poster Presentation No. 49 Evaluation of precision of digital impression technique in vivo

Baba Kazuyoshi, E. Kamimura, S. Tanaka, M. Takaba, K. Tachi Showa University, Japan

Purpose: The aim of this study was to evaluate inter-operator reproducibility of digital impression technique in contrast with conventional silicone impression technique in vivo. Materials and Methods: Twelve subjects who have no missing teeth (6 males, 6 females; mean age 26.6 ± 2.0 years) were included in this study. Impressions of mandibular molars of these subjects were made by 2 impression techniques, which used intra-oral scanner (Lava COS, 3M ESPE) and silicone impression material (Imprint 3, 3M ESPE). Both impressions were made by 2 operators with different clinical experience (3 or 15 year clinical experience). The Standard Tessellation Language (STL) data was directly exported from the COS system, while that of gypsum model made from silicone impression was obtained by 3D lab scanner (D810, 3shape). The STL datasets recorded by the 2 different operators were loaded into 3D evaluation software and superimposed using the best-fit-algorithm method (least squares method, PolyWorks, InnovMetric Software) for each impression method. Inter-operator reproducibility as evaluated by averaged discrepancies of corresponding 3D data was compared between 2 methods (paired t-test, p < 0.05). Results: The visual inspection of superimposed inter-operator datasets revealed smaller discrep-

83 39th Annual Conference of the European Prosthodontic Association ancy for the intra oral scanner, which was confirmed by the statistical analysis that revealed significantly smaller averaged discrepancy for digital impression method (19.9 ± 4.3 µm) than that for silicone impression (34.1 ± 6.6 µm, p < 0.05). Conclusions: This in vivo study demonstrated that digital impression method has superior precision in comparison with conventional silicone impression method, which is independent upon the clinical experience of the operator.

Poster Presentation No. 50 Comparison of occlusal contact during low-level clenching intensity

Osamu Komiyama, Takashi Lida, Yoshihiro Komoda, Manabu Masuda, Ryoko Obara, Misao Ka- wara Nihon University, School of Dentistry at Matsudo, Japan

Purpose: This study investigated the difference of occlusal contact area in each tooth between low level tooth clenching conditions in normal subjects. Materials and Methods: Twelve healthy men (24.8 ± 2.5 years) and 12 healthy women (24.3 ± 2.0 years) with no more than one missing tooth per quadrant participated. Surface EMG was recorded from the masseter muscle. As baseline measurement, intercuspal position was maintained with minimal force and occlusal contact was recorded with blue silicone material. Occlusal contact was also recorded at 20% Maximum Voluntary Contraction (MVC) of masseter muscle and 40% MVC using visual feedback. The occlusal contact area was analyzed using five levels of light transmit- tance through the silicone material: Level 1 (0–149 µm); Level 2 (0–89 µm); Level 3 (0–49 µm); Level 4 (0–29 µm); and Level 5 (0–4 µm). Each of teeth was analyzed separately. Results: At level 2 and 3, the occlusal contact area significantly increased from baseline to 20% MVC and to 40% MVC in the pre-molar area (p < 0.05), and it significantly increased from baseline to 20% MVC and to 40% MVC in pre-molar and molar area at level 4 and level 5 (p < 0.05). In the anterior part, there is no significant increment at all levels. Conclusions: This study showed that the occlusal contact area increased from baseline to 20% MVC or 40% MVC. It suggested that occlusal contacts may be different at low clenching intensity with potential effects on the each teeth or periodontal tissues.

Poster Presentation No. 51 The influence of impression material on the accuracy of the master cast in implant restorations

Stefos Spyridon, P. Zoidis, A. Sarafianou, S. Kourtis University of Athens, Dental School, Department of Prosthodontics, Greece

Purpose: The purpose of this study was to examine the effect of two different impression materials on the accuracy of the master cast with parallel and inclined implants. The impression materials that were used are medium body polyether and medium body silicone using a closed tray. Materials and Methods: Master cast was fabricated in epoxy resin with three dental implants embedded. Five impressions were prepared with medium-viscosity polyether and five other with medium-viscosity silicone. The technique that was tested was that of closed tray. Two light-cured custom acrylic trays were fabricated for each impression material and transfer copings were fixed on the implants. Subsequently, the ten impressions were poured in type IV die stone. The first two implants were parallel to each other (Implants A, B) and perpendicular to the horizontal level and the third implant (Implant C) had a 25° inclination to the other two. The metal framework that was constructed in the master cast was fixed to the new specimens and the micro-gap between this

84 39th Annual Conference of the European Prosthodontic Association prosthesis and the implant analogues was evaluated. The specimens were observed using optical microscope from which photos were taken and analyzed in computer software. Results: The obtained data of the micro-gap values were statistically evaluated using ANOVA and Categorical Regression analysis: 1) The marginal gaps were greater when medium-viscosity polyether was used as an impression material, than of those gaps when medium-viscosity addition silicone was used. 2) Concerning the angulated implants, the master casts that were poured from the medium-viscosity addition silicone impressions were more accurate, especially when short transfer copings were used. 3) Concerning the parallel implants, their master casts were more accurate, when short transfer copings were used. 4) Medium-viscosity addition silicone used as the impression material combined with short transfer copings produced more accurate master casts. Conclusions: Within the limitations of this study, it can be concluded that the marginal gap between the implant surface and the prosthesis is affected mainly by the impression material, the implant angulations or their interaction.

Poster Presentation No. 52 Inlay-retained monolithic zirconia fixed dental prosthesis: A case report

Melike Kan, Ender Akan Izmir Katip Celebi University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Many treatment options are available to replace a missing tooth such as conventional metal-ceramic or all ceramic fixed dental prosthesis (FDPs) or implants in the posterior region. Inlay-retained FDPs can be considered more conservative treatment option compared with full coverage FDPs, especially when adjacent teeth have pre-existing restoration. The use of all-ceramic materials for fixed restorations has become popular due to its excellent optical properties and many of these restorations can be fabricated by CAD/CAM method chairside. Furthermore the indications of all-ceramic restoration are increased by introducing zirconia to dentistry. Depending on its high mechanical properties, monolithic zirconia could be material of choice for inlay-retained FDPs. Materials and Methods: Case report: a 33-year-old man with missing maxilla right first premolar was referred to the Izmir Katip Celebi University, Department of Prosthodontics clinic. After radiographic and clinical examination; good oral hygiene, low susceptibility to caries, adjacent teeth of edentulous gap previously restored with composite filling were observed. Inlay-retained FDP was decided with monolithic zirconia using CAD/CAM technology. Filling materials were removed and deep chamber finish lines were prepared. Digital impression was taken (inLab Software, Sirona), restoration was designed and fabricated (inCoris TZI C, A3). Restoration was adhesively cemented (Panavia F 2.0) after sandblasting the internal surfaces of the restoration. Results: The technique described in this case report allows a minimally invasive approach for single-tooth substitution, as an alternative to a full-coverage FDP or an implant-supported crown. Conclusions: The demand for aesthetics and biocompatibility led to the use of monolithic zirconia CAD/CAM materials in fixed prosthodontics.

Poster Presentation No. 53 Evaluation of acid etching to shear bond strength of current CAD/CAM blocks

Onur Etoz, Murat Kurt Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthetic Dentistry, Krupelit/Sam- sun, Turkey

Purpose: The purpose of this study was to evaluate the effect of two different etching agents on the shear bond strength between two lithium disilicate glass ceramic blocks and a composite resin by

85 39th Annual Conference of the European Prosthodontic Association using two resin cements. Material and Methods: Pre-sinterized blocks of zirconia reinforced lithium silicate (ZLS); (Vita Su- prinity) and lithium disilicate blocks (IPS e.max CAD) were sectioned (2 mm), to have 80 specimens by using a precision cutting machine. The prepared specimens received crystallization heat treatment as suggested by manufacturers. Two different acids were applied on groups: hydrofluoric acid etching (HF) and acidulated phosphate fluoride etching (APF). The disks were coated with silane primer and bonded to 4 mm diameter resin composite disks using two different resin adhesives and then stored in 37 °C for 24 hours. Shear bond tests were performed in a universal testing machine with a crosshead speed of 1 mm/min. The mean bond strength of the specimens was statistically analyzed using parametric test methods (Mann-Whitney U and Student T-tests). Results: Based on the data of shear bond strength, statistically no significant differences were found between ceramic blocks (p > 0.001) with Student T-test. As surface treatment with HF acid method showed significant difference comparing to APF method. Conclusions: New generation lithium disilicate (ZLS) and lithium disilicate glass ceramics did not show any statistically differences on shear bond strength among them.

Poster Presentation No. 54 Incidence of combination syndrome over a five-year period at the University of Pécs, De- partment of Prosthodontics

Dóra Markovics1, Róbert Szendi2, Kristina Vicko3, Zsolt Rajnics1, Gyula Marada1, Márta Radnai1 1University of Pécs, Medical Faculty, Dental School, Department of Prosthodontics, Hungary 2Southgate Dental Ltd., Drogheda, Ireland 3University of Novi Sad, Faculty of Medicine, Department of Dentistry, Serbia

Purpose: The treatment of patients having a completely edentulous maxillary arch and lower anterior teeth present is frequent in the dental practice. In these cases some specific changes can be detected in the oral cavity and on x-rays. These signs were summarized and described first by Kelly (1972). Materials and Methods: Aim of the study was to examine the presence of the specific signs of the combination syndrome among the patients between 2009 and 2014. With the help of the electronic patient registry system used by the University of Pécs, 319 patients were filtered who were diagnosed with anodontia code (K0000 International Classification of Diseases [ICD]) in the examined period. Results: 220 patients´ orthopantomographs were evaluated searching for specific symptoms of the combination syndrome. 34 patients had complete edentulous maxilla and anterior teeth in the mandible. 4 patients (11.7%) showed the main sign of the combination syndrome, i. e. the maxillary anterior bone loss. Hypertrophy of maxillary tuberosity (9 cases, 26.4%), extrusion of the lower anterior teeth (6 cases, 17.6%) and great resorption of the distal mandibular ridge (16 cases, 47%) was diagnosed on the x-rays. The clinical examination of three patients supported the radiological findings. Conclusions: Different signs of the combination syndrome were detectable, but the incidence rate was lower in this population in comparison with the results available in dental scientific publications.

Poster Presentation No. 55 The evaluation of development process of OHIP questionnaire

Baran Ilgi, Hamiyet Güngör Kirikkale University, Turkey

Purpose: The oral health impact profile (OHIP) is one of the most important measurement instru- 86 39th Annual Conference of the European Prosthodontic Association ments of human perception of the social impact of oral disorders on their daily life. The OHIP questionnaire has 49 questions in original but it can be time consuming, so only 14 items were extracted from 49 items and provided good statistical properties. The aim of this study was to evaluate the content of OHIP articles towards years and cultures. Materials and Methods: We searched the literature from 1995 and 2015 about OHRQoL measured by OHIP who had prosthodontic treatment. Results: The short form of OHIP is generalized from past to today and this form generally applied in elderly for every country. Conclusions: Both the short and the long form of OHIP are quite adequate method to assess OHRQoL.

Poster Presentation No. 56 Influence of increment thickness on the shear-bond-strength and light-irradiance of composite-based materials

Tarek Ashraf Omran, Sufyan Garoushi, Aous Abdulmajeed, Lippo Lassila, Pekka Vallittu University of Turku, Institute of Dentistry, Department of Biomaterials Science, Finland University of Turku, Turku Clinical Biomaterials Centre (TCBC), Finland

Purpose: Bulk-fill composites (BFC) are gaining popularity in restorative dentistry due to the significant reduced chair-time. The aims of this study were to determine and compare the influence of increment thickness on dentin bond strength and amount of light-irradiance of different BFC’s. Materials and Methods: One hundred and eighty extracted and sound human molars were prepared for Shear Bond Strength (SBS) testing. The teeth were then divided into four groups (n = 45) according to the filling material used; (1) G-ænial Anterior, (2) Tetric EvoCeram Bulk Fill, (3) SDR, (4) EverX Posterior. Each group was subdivided according to increment thickness: (2, 4 and 6 mm). In parallel, the amount of light irradiance for all groups and subgroups were quantified using (MARC® Resin Calibrator; BlueLight Analytics Inc.), measured at the bottom layer. Data were analyzed using two-way ANOVA followed by Tukey’s post-hoc test. Results: SBS and light irradiance decreased as the height of increments increases (p < .05), regardless of the type of BFC. SBS and irradiance mean values arranged in descending order was as follows (p < .05): EverX Posterior, SDR, Tetric EvoCeram Bulk Fill and G-ænial Anterior. Conclusions: Besides being a reinforcing base with crack propagation inhibition and reduced polymerization shrinkage, EverX Posterior could potentially be used clinically as BFC.

Poster Presentation No. 57 Effect of gastric acidic challenge on surface topography of monolithic zirconia

Khalil Shahramian, Taiseer A. Sulaiman, Aous A. Abdulmajeed, Timo O. Närhi University of Turku, Faculty of Medicine, Institute of Dentistry, Finland

Purpose: To evaluate the surface topography of monolithic zirconia after immersion in simulated gastric acid. Materials and Methods: Four partially stabilized (PSZ) and one fully stabilized (FSZ) zirconia materials were evaluated in this study: Prettau (PRT) from Zirkonzahn, Zenostar (ZEN) from Ivo- clar, Bruxzir (BRX) from Glidewell, Katana (KAT) from Noritake and Prettau Anterior (PRTA) from Zirkonzahn, respectively. IPS e.max from Ivoclar was used as a control. The specimens (10 × 10 × 1.2 mm, n = 5 per material) were cut, sintered, polished and cleaned before immersed in 5 ml of simulated gastric acid solution (hydrochloric acid, 0.06 M, 0.113% solution in deionised distilled water, pH 1.2 for 96 hours in a 37 °C incubator. Specimens were weighed and examined for mor-

87 39th Annual Conference of the European Prosthodontic Association phological changes under scanning electron microscope (SEM) coupled with energy dispersive x-ray spectroscopy (EDX).Surface roughness was evaluated by a confocal microscope. The data were analyzed by one-way ANOVA followed by Tukey’s HSD post hoc test (p < 0.05). Results: PRTA displayed the highest weight loss (1.40%) among the zirconia specimens. IPS e.max showed about three times higher weight loss (3.05%) than zirconia specimens as an average. SEM examination indicated areas of degradation, bead-like shapes and smoothening of the polishing scratches after acid immersion. EDX displayed ion interactions and possible ion leaching from all specimens. Sa and Sq values for PRTA, ZEN and IPS e.max were significantly lower (p < 0.05) after acid immersion. Conclusions: Monolithic zirconia showed potential resistance to acidic challenge in vitro. Whether a smoother surface is in fact a sign of true corrosion resistance or is purely the result of an evenly progressive corrosive process is yet to be determined.

Poster Presentation No. 58 Effect of shoulder lithium-disilicate on marginal leakage of CAD-on crowns

Bahar Elter, Gamze Paken, Erhan Comlekoglu, Atilla Kesercioglu Ege University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: To evaluate the influence of shoulder lithium-disilicate ceramic on marginal leakage of CAD/CAM split-file zirconia based crowns. Materials and Methods: Ten freshly extracted human molars were collected and distal half of each tooth was prepared with chamfer type margin, while mesial half was finished with mini-chamfer. Following digital impressions, zirconia frameworks were designed (Cerec 4.3, Sirona, Bensheim, Germany). Restoration margins on the mesial halves were designed as zirconia and on the distal halves zirconia margins were veneered with lithium-disilicate glass ceramic. Zirconia frameworks were milled and sintered. Lithium-disilicate veneering parts were milled, luted on zirconia frameworks, crystallized and glazed. Finished crowns were cemented on teeth (Multilink N) and 5,000 cycles of thermocycling (5–55 °C) were performed. Specimens were immersed in basic fuchsine solution for 24 hours. Four cross-sections were received from each crown and inspected for micro- leakage under a stereomicroscope (Leica, 20x). Micro-leakage scorings were calculated millimetri- cally and data were statistically analyzed (Mann-Whitney U Test, α = 0.05). Results: Statistical tests showed significant difference between two groups (p < 0.05). Mean micro- leakage scores for each group were recorded and the highest micro-leakage was noted with lithium disilicate margin design (1.17 ± 0.69). Zirconia margin group showed lower micro-leakage scores (1.03 ± 0.74). Conclusions: Lithium disilicate added margin designs for zirconia crowns were not effective in reducing marginal micro-leakage, conversely restoration margins which are designed as zirconia only yielded better micro-leakage results.

Poster Presentation No. 59 Guidelines for acceptable scientific poster: A literature review

Haniyeh Sazvar, S. M. R. Sazvar Iran University Medical of Sciences, Tehran, Iran

Purpose: In most congress or scientific meeting usually there are some posters with very useful and practical scientific contents but unfortunately they have many problems in them so they could not attract the attendee`s attention. Therefore this study was accomplished with the purpose of preparing basic rules for a useful poster.

88 39th Annual Conference of the European Prosthodontic Association

Materials and Methods: In literatures review the keywords “guidelines – scientific – posters” were searched in: www.pubmed.org and www.google.com and among 103 subjects, 43 efficient literatures were evaluated. Then the common rules, guidelines and recommendations were summarized in this poster. Results: Almost all literatures pointed out to many problems in creating a poster. The most common faults were in poster size, colour, font size and thrusting many words in a limited area. Although some literatures had been emphasized on attractive style and design but many posters had not contained. Conclusions: With limitations of this research, for preparing a poster the mentioned basic rules must be accomplished, otherwise it could be frustrated and/or not attractive for readers.

Poster Presentation No. 60 Investigation of styloid process length in a Greek adults’ population

Nikolaos Zokaris, I. Siska, A. Knaus, E. Piehslinger MedUni, Wien, Austria

Purpose: The styloid process is a slender cylindrical bony projection of the temporal bone with two ligaments and three muscles attached to it. The symptomatic elongation of the styloid process is also referred to, as Eagle Syndrome. There is no unique statement however on what seems to be the normal length of the process. The aim of the present study is to investigate the distribution of length of the styloid process in a Greek young adults’ population. Materials and Methods: The sample comprised of student pilots and engineers entering the Hel- lenic Air Force Academy, from 2008 and onwards. 567 Digital Panoramic Radiographs and the corresponding software were utilized for the length measurements. Defined landmarks used were the end tip of the process and the lower margin of the tympanic plate. Inter and intra examiner variability was also tested. Results: The mean length of the complex was 27.4 mm for the right side and 27.7 mm for the left side. 22.6% of the processes measured exceeded 30 mm which is most commonly used as a cut off value for elongation. Conclusions: Styloid process is normally both detectable and measurable in OPGs. Even if the measurement may lack the absolute preciseness an elongated process is usually clearly depicted and must be kept in mind. Since symptoms of elongation may overlap with symptoms of TMD and since OPGs are routinely used, the dental professionals must be familiar with this clinical and radiological entity.

Poster Presentation No. 61 Implant-supported prosthetic rehabilitation with anterior iliac grafting in an adult cleft patient

Emrah Baca, S. C. Isler, T. Celakil, E. Akbas, G. Evlioglu Istanbul University, Faculty of Dentistry, Capa Fatih Istanbul, Turkey

Purpose: The aim of this case report was to fabricate a fixed prosthesis in an adult cleft lip palate patient who had a congenital defect in anterior maxillae complaining of mastication, speaking and aesthetic problems. Materials and Methods: The patient was operated under general anaesthesia with nasotracheal intubation. The repair of the alveolar defect began with infiltration anaesthesia in the vestibular and palatal areas. Vestibular incision was made and mucoperiostal flap was released on the vestibular side. Another incision was performed to separate the gingival mucosa from the nasal mucosa.

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Then, the nasal mucosa was separated from the oral mucosa in order to lift it towards the floor of the nose. Following this procedure, harvested anterior iliac bone was grafted into the cleft side with two mini titanium screws. Finally, the flap was closed with 4.0 mm polyglactin suture. After 4 months, gingival formers were placed. After 3 weeks, impression was taken with polyvinylsiloxane (PVS) impression material. Titanium custom abutments were fabricated for correction of implant angulation. Zirconia-supported fixed prostheses were inserted. Results: The patient had a great satisfaction with the appearance and function. The patient was followed for 6 months and was instructed to comply with an oral hygiene programme on a one month recall schedule. Conclusions: Implant-supported fixed prostheses in adult cleft lip palate patients have excellent aesthetic appearance and function.

Poster Presentation No. 62 Efficacy of water cooling in different implant systems – thermographic analysis

Karol Kirstein2, Maciej Dobrzyński1, Piotr Kosior1 Aleksander Chrószcz2, Krzysztof Dudek3, Katar- zyna Fita1, Olga Parulska4, Zbigniew Rybak5, Maciej Janeczek2 1Wroclaw Medical University, Department of Conservative Dentistry and Pedodontics, Poland 2Wroclaw University of Environmental and Life Sciences, Department of Biostructure and Animal Physiology, Poland 3Technical University of Wroclaw, Institute of Machines Design and Operation, Poland 4Wroclaw Medical University, Department of Dental Surgery, Poland 5Wroclaw Medical University, Department of Experimental Surgery and Biomaterials Research, Poland

Purpose: The aim of the study was the evaluation of efficacy of water cooling in different systems during implant placement procedure. Materials and Methods: The study was performed on raw swine rib bone model. Four implant systems (Bergo®, 3I®, Sybron®, NeoBiotech®) were evaluated. The material was divided into five groups, including one without irrigation. During drilling, the potential overheating level of the bone tissue was recorded with thermo vision infrared camera (ThermoVision A20 M). The experiment took place in a room with a temperature of 24–26 degrees Celsius with humidity of 50–70%, without dust, vapours, and minimum air movement in the room. After drill-hole preparation, the neigh- bouring tissue was taken for histological and ultra-structural investigations. Achieved results were statistically analyzed. Difference significance was verified by Friedman ANOVA and Kruskal-Wallis ANOVA at the level p < 0.05. Results: The lack of significant differences in drilling temperature between investigated devices was proved. In the case of drilling without any irrigation, the bone tissue destruction as well as exceed- ing of critical temperature disruptive osseointegration process was shown. All investigated irrigation systems effectively prevent bone overheating. The histological and ultra-structural investigations showed the changes typical for mechanical and thermal injuries and destruction of bone tissue. Conclusions: Effective cooling system use plays the crucial role in implantation procedures, especially in mechanic drilling. The analyzed irrigation systems were comparable in bone overheating prevention. It may be concluded that infrared thermography can be used as an objective, non- invasive, and quantitative tool in temperature estimation during implant placement procedure.

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Poster Presentation No. 63 Framework fit of removable partial dentures fabricated with different manufacturing techniques

Christin Arnold, R. Schweyen, J. Hey, T. Bensel, J. Setz Martin Luther University Halle-Wittenberg, Centre for Dentistry and Oral Medicine, Department of Prosthodontics, Germany

Purpose: The aim of the present in vitro-study was to compare the framework fit of removable partial dentures (RPD) fabricated with the conventional lost-wax technique (LWT) and 4 different computer assisted technologies. Materials and Methods: An upper model with both molars and canines as residual teeth served as the master pattern for the fabrication of a total of 15 RDP’s with equal construction. Beside LWT the following techniques were used to produce 3 RDP’s, respectively: indirect CAM milling technology (ICT), direct CAM milling technology (DCT), rapid prototyping technology (RP) with direct inject printing (RPC) and RP with selective laser sintering (RPM). In all computer assisted technologies the same framework’s design and dataset was used. Measurements of frameworks’ fit were taken on the master pattern at the clamps’ arms in horizontal and vertical direction using a light microscope. Statistical analysis was performed using SPSS 20.0 (Mann-Whitney U-test, p < 0.05). Results: The conventional method (LWT) showed marginal discrepancies of 106 ± 60 µm. High- est fitting accuracy was found in RDP’s fabricated with CAM milling technology with an average gap size of 41 ± 25 µm (DCT) and 84 ± 51 µm (ICT). Lowest fitting accuracy was found in RDP’s fabricated with RP technology with an average gap size of 227 ± 180 µm (RPC) and 359 ± 184 µm (RPM). All techniques differed in a significant way (p < 0.001). Conclusions: In contrast to RP, the use of CAM-technology seems to improve the fitting accuracy of RDP’s in comparison to the conventional LWT.

Poster Presentation No. 64 Laser treatments effects on bond strength of differently sintered zirconia

Dogu Ömür Dede1, Murat Yenisey2, Nergiz Rona2, Figen Öngöz Dede3 1Ordu University, Faculty of Dentistry, Department of Prosthodontics, Turkey 2Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Samsun, Turkey 3Bülent Ecevit University, Faculty of Dentistry, Department of Prosthodontics, Zonguldak, Turkey

Purpose: This study investigated the effects of surface treatments by laser irradiations on the bond strength of differently sintered zirconium-oxide ceramics to resin cement. Materials and Methods: 80 zirconia specimens were prepared, sintered in two different periods (short = Ss, long = Ls) and divided into four treatment groups of 10 as follows: a) No surface treatment applied; b) Er:YAG laser irradiated with 2 W power for 10 sec; c) CO2 laser with 2 W power for 10 sec; d) CO2 laser with 4 W power for 10 sec. 80 composite resin discs were fabricated and cemented with an adhesive resin cement to ceramic specimens. The shear bond strength test was performed after specimens were stored in water for 24 hours by a universal testing machine at cross shed speed of 1 mm/min. Data were statistically analyzed with two-way analysis of variance (ANOVA) and Tukey HSD test (α = 0,05). Results: According to the ANOVA, the sintering time, surface treatments and their interaction were statistically significant (p < .05). While each laser irradiating groups were significantly higher than the control groups, there was no statistically significant difference among them (p > .05). Conclusions: Sintering time may be effective on the bond strength values and both Er:YAG and

CO2 laser irradiation would increase the bond strength between resin cement and differently sintered zirconium-oxide ceramics.

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Poster Presentation No. 65 Cement and core materials effects on the colour of ceramics

Ersan Celik1, Doğu Ömür Dede1, Onur Şahin2, Oğuz Süleyman Özdemir3 1Ordu University, Faculty of Dentistry, Department of Prosthodontics, Turkey 2Bülent Ecevit University, Faculty of Dentistry, Department of Prosthodontics, Zonguldak, Turkey 3Samsun Public Oral Health Centre, Turkey

Purpose: The aim of this study was to evaluate the effects of luting cement and composite core materials on the final colour of lithium disilicate ceramic systems. Materials and Methods: Twenty A2 shade ceramic discs (11 × 1.5 mm) were fabricated from IPS e.max medium-opacity (mo) (n = 10) and high-translucency (ht) (n = 10) frameworks. Additionally, five composite resin background discs (11 × 3 mm) were prepared from different shades (A1, A2, A3, B2, C2) and 30 luting cement discs (11 × 0.2 mm) from the shades of translucent, universal (A2) and white-opaque resin luting cement. The colour measurements of each ceramics were performed on each background and cement samples with a digital spectrophotometer and data recorded as CIE L* a* b* coordinates. The colour coordinates of ceramics on A2 shade composite and universal shade cement samples served as the control. Colour differences (ΔE 00) between control and other groups were calculated. Data were analyzed by three-way variance analysis (ANOVA) and Tukey HSD test (α = .05). Results: The ΔE 00 values were affected by luting cement, composite core materials and their interactions (p < .05). The use A1, A3 and B2 shades of composites with WO-shade cement caused an unacceptable colour differences (ΔE 00 > 2.25) for both lithium disilicate ceramic systems. Conclusions: The optical properties of composite core and cement layers would be affective on the final colour of lithium disilicate ceramics. Clinicians must be aware of this interaction, especially while using white-opaque cements.

Poster Presentation No. 66 Evaluation of marginal/internal fit of Co-Cr crowns: Direct-laser-metal-sintering versus CAD/ CAM

Selim Günsoy, Mutahhar M. Ulusoy, Simge Taşar Near East University, Faculty of Dentistry, Department of Prosthodontics, Turkish Republic of Northern Cyprus

Purpose: The purpose of the study was to evaluate the internal and marginal fit of Co-Cr crowns fabricated with laser sintering, CAD/CAM and conventional methods. Materials and Methods: Polyamide master and working models were designed and fabricated. The models were initially designed with a software application for 3D computer-aided design (Maya, Au- todesk Inc.). All models were produced by a 3D printer (EOSINT P380 SLS, EOS). 128 one-unit Co- Cr fixed dental prostheses (FDPs) were fabricated with four different techniques: Conventional lost wax method (CLW), milled wax with lost-wax method (MCLW), direct laser metal sintering (DLMS) and milled Co-Cr (MCo-Cr). The cement film thicknesses of the marginal and internal gaps were measured by an observer using a stereomicroscope after taking digital photos in x24 magnification. Results: Best fit rates according to mean and standard deviations of all measurements were in DLMS both in premolar (65.84) and molar (58.38) models in µm. Significant difference was found in DLMS and the rest of fabrication techniques (p < 0.05). No significant difference was found between MCo-CR and MWLW in all fabrication techniques both in premolar and molar models (p > 0.05). Conclusions: DLMS was best fitting fabrication technique for single crown based on the results. All groups were within the clinically acceptable misfit range.

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Poster Presentation No. 67 Interarch relationship measured in transversal view using digital 3D models

Heikki (Tuomas) Kiviahde, P. Jussila, K. Sipilä, P. Pirttiniemi University of Oulu, Faculty of Medicine, Institute of Dentistry, Finland

Purpose: To evaluate the method for measuring interarch relationship in transversal view using 3D models. Materials and Methods: The sample comprised of 30 sets of study models randomly selected from Northern Finland 1966 Birth Cohort (Sipilä et al., 2001). Dental casts were placed in intercuspal position and scanned by 3Shape® 3D Scanner. Measurements were done on 3D digital models using 3Shape Ortho Analyzer software. Measurements were performed in transversal view and marked points in both dental arches were projected to the buccal sagittal plane. The measurements included bilateral first-molar relationship, bilateral canine relationship, transversal inter-molar asymmetry and midline asymmetry. All measurements were repeated in two weeks. Results: Mean errors between repeated measurements were: for right first-molar relationship 0.12 mm (range 0.00–0.39 mm) and for left one 0.10 mm (range 0.00–0.20 mm), for right transversal intermolar asymmetry 0.15 mm (range 0.01–0.42 mm) and for left one 0.11 mm (range 0.00–0.30 mm), for right canine-relationship 0.12 mm (range 0.01–0.88 mm) and for left one 0.09 (range 0.01–0.26 mm). Mean error for midline asymmetry was 0.07 mm (range 0.00–0.24 mm). Conclusions: The study shows that using 3D models and 3Shape Ortho Analyzer software is a valid and repeatable method in interarch relationship measurements.

Poster Presentation No. 68 Manual and digital measurement of occlusal characteristics in sagittal view

Lea Bukovac, P. Pirttiniemi University of Oulu, Faculty of Medicine, Institute of Dentistry, Finland

Purpose: To evaluate the reliability and accuracy of measurements comparing manual measurements made on dental casts with measurements on digital 3D models in sagittal view. Materials and Methods: The study sample comprised of 30 models of subjects randomly selected from Northern Finland 1966 Birth Cohort (Sipilä et al., 2001). Dental casts were placed in intercuspal position and scanned with 3Shape® 3D Scanner. Measurements were done on dental casts using digital calliper and on 3D digital models using 3Shape® Ortho Analyzer software in sagittal view. Marked points in both dental arches were projected to the occlusal plane. The measurements included bilateral first-molar relationship, bilateral canine relationship in the sagittal view and midline asymmetry in the frontal view. All measurements were repeated after two weeks. Results: Mean errors in digital measurements were: for right first-molar relationship 0.07 mm (range 0.00–0.23 mm) and for left one 0.11 mm (range 0.00–0.39 mm), for right canine relationship 0.10 mm (range 0.00–0.34 mm) and for left one 0.14 mm (range 0.00–0.43 mm) and for midline asymmetry 0.11 mm (range 0.00–0.48 mm). Mean errors in manual measurements were: for right first- molar relationship 0.22 mm (range 0.00–0.83 mm) and for left one 0.17 mm (0.00–0.55 mm), for right canine relationship 0.21 mm (range 0.00–0.57 mm) and for left one 0.20 mm (range 0.03–0.66 mm) and for midline asymmetry 0.21 mm (range 0.00–0.63 mm). Conclusions: The study shows that measurements of inter-arch occlusal relationship using digital 3D models have better accuracy and repeatability than manual measurements using dental casts.

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Poster Presentation No. 69 Measurement of overbite and overjet using digital 3D

Päivi (Hannele) Jussila, L. Bukovac, H. Kiviahde, K. Sipilä, A. Raustia University of Oulu, Faculty of Medicine, Institute of Dentistry, Finland

Purpose: To evaluate accuracy of measurements of overbite and overjet made on digital 3D models with measurements made on conventional dental casts. Materials and Methods: The sample comprised of 30 sets of study models of subjects randomly selected from Northern Finland 1966 Birth Cohort (Sipilä et al., 2006). Dental casts placed in intercuspal position were scanned by 3Shape® 3D Scanner®. Measurements of overbite and overjet were done on conventional dental casts using digital calliper and on 3D digital models using 3Shape® Ortho Analyser software®. Measurements were performed in frontal and sagittal view. All the measurements were repeated in two weeks. Results: Mean error between repeated measurements on digital models was 0.13 mm (range 0.00–0.45 mm) for overbite and 0.15 mm (range 0.00–0.86 mm) for overjet. Mean error in manual measurements was 0.21 mm (range 0.00–0.58 mm) for overbite and 0.27 mm (range 0.02–0.82 mm) for overjet. Conclusions: It can be concluded that measurements performed on digital 3D models show better accuracy and repeatability compared to manual measurements of overbite and overjet.

Poster Presentation No. 70 Comparison of three sintering methods

Hasan Murat Aydogdu, Murat Eskitascioglu Yuzuncu Yil University, Faculty of Dentistry, Turkey

Purpose: To compare the sintering shrinkage of zirconia frameworks sintered with three different methods. Materials and Methods: A CAI/CAD/CAM system (Cerec 3) was employed to produce 72 identical zirconia single crown frameworks on a cast metal mandibular molar abutment. All frameworks were milled by the same milling device (inLab MCXL) based on one digital design file. Occlusal and buccal dimensional measurements based on marked reference points were done with a Toolmaker’s microscope. Four reference points were marked on each surface of the projection area and perimeter between four points were calculated. Frameworks were randomly assigned to three groups to be sintered with three determined programs with durations of 8 hours, 2 hours and 10 minutes. All dimensional measurements were repeated after sintering. Results: Projection area and perimeter changes after sintering were calculated and the sintering shrinkage of zircoina frameworks for three sintering groups were compared. The occlusal surface shrinkage values of 8 hour, 2 hour and 10 minute sintering groups were -20.283%, -20.435%, -20.341% for perimeter and -36.437%, -36.693%, -40.217% for area respectively. Buccal surface shrinkage values of 8 hour, 2 hour and 10 minute sintering groups were -20.052%, -20.107% and -20.087% for perimeter and -36.064%, -36.075% and -36.065% for area respectively. Statistical analysis shows there is no significant difference between three groups (p > 0.05). Conclusions: The sintering shrinkage of zirconia single crown frameworks with 8 hour, 2 hour and 10 minute sintering programs were comparable.

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Poster Presentation No. 71 The investigation of the marginal micro-leakage of ceramic veneer crowns with different finish lines Akin Ceyda1, Ozgur Inan2 1University of Necmettin Erbakan, Faculty of Dentistry, Department of Prosthodontics, Turkey 2Selcuk University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: All-ceramic crowns offer good biocompatibility and aesthetic appearance and have been used successfully to restore anterior and posterior teeth. Micro-leakage is an important factor that affects the longevity of all-ceramic crowns. The purpose of this study was to evaluate the micro- leakage of heat pressed all-ceramic crowns made from IPS Empress eMax which were cemented with two different resin cements on the prepared teeth with two different finish lines, chamfer and rounded shoulder. Materials and Methods: Forty extracted premolars were prepared for complete crowns with 2 different marginal finish lines (chamfer and rounded shoulder) (n = 20); IPS Empress eMax restorations were cemented using different 2 resin cements (RelyX U200 and Multilink N) (n = 10). Samples were thermocycled (5000), stained with 0.5% basic fuchsine, sectioned and examined under stereomicroscope. The extent of micro-leakage on gingival margins of the restorations was scored and recorded. Results: Statistically no significant difference was observed between shoulder and chamfer groups (p > 0.05). However significant difference was found in RelyX compared with Multilink N (p < 0.05). Conclusions: Multilink N resin cement showed significantly higher values for micro-leakage while marginal finish line design had no effect on micro-leakage for IPS Empress eMax crowns.

Poster Presentation No. 72 The effect of flow rate during laser irradiation on the bond strength of zirconia

Omer Kirmali1, Kurtulmus-Yilmaz Sevcan2, Akin Hakan3 1Akdeniz University, Faculty of Dentistry, Department of Prosthodontics, Antalya, Turkey 2Near East University, Faculty of Dentistry, Department of Prosthodontics, Nicosia, Turkey 3Cumhuriyet University, Faculty of Dentistry, Department of Prosthodontics, Sivas, Turkey

Purpose: The aim of this study was to determine the effect of different flow rates during Er,Cr:YSGG laser irradiation on the shear bond strength (SBS) of zirconia cores to a resin cement. Materials and Methods: Fifty fully sintered zirconia specimens were divided into 5 groups according to the surface treatment applied (n = 10); control group (no surface treatment) (n = 10): airborne- particle abraded with Al2O3 particles and Er,Cr:YSGG laser irradiation with different flow rates (1%, 50% and 100%). After surface treatments, resin cements were applied on zirconia core specimens with the use of a cylindrical mould. SBS test was performed on all bonded specimens at a crosshead speed of 1 mm/min until fracture. In order to compare results of the bond strength, one-way ANOVA and post hoc Tukey-Kramer multiple comparisons tests (α = 0.05) were used. Results: Control group of specimens were exhibited the highest SBS values. All surface treatment methods did not improve the bond strength of the specimens (p > 0.05). Conclusions: Bond strength of zirconia to resin cement is independent of the surface pre-treatments with both Er,Cr:YSGG laser and sandblasting.

Poster Presentation No. 73 Clinical follow-up of zirconia partial fixed dental prostheses

Juha Pihlaja, Ritva Näpänkangas, Aune Raustia University of Oulu, Finland 95 39th Annual Conference of the European Prosthodontic Association

Purpose: This retrospective clinical follow-up study purposed to evaluate the outcome of zirconia partial fixed dental prostheses made by dental students after 3 to 7 years of clinical service. Materials and Methods: Altogether 102 patients had received 120 zirconia partial fixed dental prosthesis (range 3 to 12 units, mean 4.5 units) made by predoctoral dental students between 2007 and 2010. An invitation letter to clinical examination was sent and 76 patients (80%) attended the clinical follow-up (48 women and 28 men; mean age of 61 years, range 29–81 years). Patients received 88 zirconia partial fixed dental prostheses that consisted of 387 units, of which 250 were abutments and 137 pontics. Results: The majority of restorations consisted of 3 or 4 units and the mean follow-up period was 4.9 years (range from 3 years to 7 years).The most common complication was chipping of veneering porcelain (13/387 units, 3.4%). The survival rate of the zirconia partial fixed dental prostheses after 3 to 7 years was 100%. Conclusions: Results of this retrospective clinical follow-up study show that zirconia is a suitable material for short and long span fixed dental prosthesis both in anterior and posterior region.

Poster Presentation No. 74 Effect of sleep and physical activity on chronic myalgia

Shoichi Ishigaki, Koichiro Uno, Hirofumi Yatani Osaka University, Graduate School of Dentistry, Japan

Purpose: The objective of this study is to clarify how sleep and physical activities affect chronic myalgia in TMD patients. Materials and Methods: Female TMD patients (n = 7) and female non-TMD patients (n = 9) were recruited. Sleep condition and physical activities were recorded with Actigraph for 14 consecutive days. Subjects were requested to answer following questionnaire everyday: 1) subjective jaw pain intensity at every three hours after awakening; and 2) subjective assessment of the quality of sleep. These parameters were statistically analyzed using a mixed effect model in which patient’s age and the presence of menstruation were compensated. This study was approved by the Ethics Commit- tee of the Osaka University, Graduates School of Dentistry and was supported by Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research (B) #25293392. The authors have no conflict of interest. Results: The higher the previous day’s physical activity (OR = 0.992, p = .000, 95% CI: -0.0110~ -0.0040) and the quality of last-night sleep (OR = 0.997, p = .038, 95% CI: -0.0050~-0.0001), the lower the jaw pain in the first period became. The higher the previous day’s physical activity (OR = 0.997, p = .033, 95% CI: -0.0053~-0.0002) and the quality of last-night sleep (OR = 0.993, p = .001, 95% CI: -0.0099~-0.0026), the lower the jaw pain in the second period became. The higher the jaw pain of the previous day, the lower the sleep quality became (Odds ratio = .993, p = .049, 95% CI: .987~.999). Conclusions: These results suggest that sleep quality and physical activities affect chronic myalgia and that the chronic myalgia and sleep status could form the vicious cycle.

Poster Presentation No. 75 Bennett angle at different Angle’s classes of occlusion

Samir Čimić, S. Kraljević Šimunković, A. Ćatić University of Zagreb, School of Dental Medicine, Croatia

Purpose: The Bennett angle is an important parameter during prosthodontic rehabilitation. Existing data about impact of different occlusion types on the values of the Bennett angle are scarce. The

96 39th Annual Conference of the European Prosthodontic Association purpose of this study was to investigate effect of different occlusion types on the Bennett angle values. Materials and Methods: Study included 98 participants (26.0 ± 5.2 years) divided into four study groups: Angle’s class I, Angle’s class II, subdivision 1, Angle’s class II, subdivision 2 and Angle’s class III. All recordings were obtained using ultrasound jaw tracking device with six degrees of freedom. After paraocclusal tray was fixed on the lower jaw, every subject had to make three protrusive, three left and right laterotrusive movements. From the laterotrusive movements, device’s software automatically calculated Bennett angle values for left and right joints, and data were statistically analyzed. Results: One-way ANOVA did not show differences between different Angle’s classes of occlusion for the Bennett angle values. Average Bennett angle value for all participants was 7.7°. Conclusions: Our results suggest that different Angle’s classes of occlusion do not have impact on the Bennett angle values. Average value of the Bennett angle is 8°, and should be used for average articulator settings.

Poster Presentation No. 76 Effect of daytime biofeedback training on sleep electroencephalograms

Hidetoshi Otsuka, Masayuki Sato, Akira Watanabe, Konatsu Saito, Naoki Iwase, Mikiko Kawai, Kodai Hashido, Masanori Fujisawa Meikai University, School of Dentistry, Department of Restorative and Biomaterials Sciences, Divi- sion of Fixed Prosthodontics, Japan

Purpose: Sleep bruxism (SB) is one of well-known sleep disorders. In a previous study, daytime electromyogram (EMG) biofeedback (BF) training aimed at regulating awake bruxism was also found to be effective in reducing SB. Therefore, this study aimed to investigate the effect of daytime EMG-BF training on sleep electroencephalograms (EEG) in subjects with SB. Materials and Methods: Five male subjects diagnosed as having SB (age: 23.2 ± 0.8 years) were recruited for this study. The diagnosis of SB was also verified by polysomnogram (PSG) sleep recordings for one night. The subjects were randomly divided into two groups: a BF group (n = 3) and a control (CO) group (n = 2). In both groups, EMG recordings for three consecutive weeks were taken. Although the BF group recognized EMG activities exceeded the threshold in week 2, no BF signal was received in weeks 1 and 3 in the BF group or throughout the entire recording period in the CO group. The EEG recordings were taken during sleep in both groups. The power spectra of the EEG delta band and alpha band were analyzed using FFT algorithm. Results: In the BF group, the alpha band power decreased and the delta band power increased during weeks 2 and 3 compared with those in week 1. Furthermore, in the BF group, the ratios of sleep stages 3 and 4 increased in weeks 2 and 3. Conclusions: Daytime EMG-BF training may help improve the quality of sleep.

Poster Presentation No. 77 A correction method using colour information on facial point group

Daisuke Teshigawara, Teruo Ino, Satoshi Endo, Hiromasa Noro, Kinue Sugawara Meikai University, School of Dentistry, Department of Restorative and Biomaterials Sciences, Divi- sion of Fixed Prosthodontics, Japan

Purpose: A three-dimensional (3D) measurement system consisting of a digital camera with two lenses and an application to analyze 3D images has been recently developed to measure the distances in remote locations. Similar to a camera, this system is portable and can easily photograph

97 39th Annual Conference of the European Prosthodontic Association objects. In a facial measurement scenario, it can appropriately and easily capture facial expres- sions with eyes opening. However, the capacity to build the 3D point group data was significantly influenced by object surface and colour qualities. To acquire detailed facial measurement information using the portable system, a correction method using colour information on point group data was investigated. Materials and Methods: A stone facial model and a wax facial prosthesis were chosen as objects. Two stereo images were photographed using a general-purpose digital camera. Then, a 3D point group data was built using space measurement software. A noise removing procedure using the down sampling of digital colour information allowed for data smoothing. Results: In addition to the effect of normal down sampling, the correction with light intensity detection allowed detecting more micro-structures and removing object noise. It is considered that light intensity is related to the actual irregularity of objects. The correction using colour information to remove noise on a point group may be valid for facial measurements. Conclusions: The correction method using colour information is effective in removing noise in point group data.

Poster Presentation No. 78 In vitro evaluation of biaxial flexural strength of all-ceramics

Dikicier Sibel Corlu Military Hospital, Department of Prosthodontics, Tekirdag, Turkey

Purpose: The purpose of this study was to investigate the influence of core thickness and artificial aging on the biaxial flexural strength of selected all-ceramic systems. Materials and Methods: In-Ceram Alumina (IC), IPS e.max Press (EM), Katana (K) was tested. Each all-ceramic group contained two core groups based on the core material thickness as follows: 0.5 or 0.8 mm. Specimens from each core group were subjected artificial aging and all specimens were tested for biaxial flexural strength in a universal testing machine either with or without being subjected aging. Results: Aging procedures slightly decreased flexural strength in EM and IC. K group was not significantly affected by the aging regardless of the core thickness (p < 0.05). Core thickness had a statistically significant effect on flexural strength among the core groups. There were no significant differences between the before and after aging flexural strength values for the same core groups. Conclusions: This study indicated that aging showed different effects on the strength of IPS e.max Press, In-Ceram Alumina, or Katana systems. Katana system exhibited greater flexural strength values. Decreases in flexural strength after aging were not significant in all core groups.

Poster Presentation No. 79 Effect of pH on the formation of hydroxyapatite in PEO process with hydrothermal treatment of the Ti alloy

Svetlana Lugovskoy, A. Kossenko Ariel University, Israel

Purpose: Synthesis of hydroxyapatite on the surface of Ti6Al4V alloy was performed. Structure, morphology and properties of the surface layer were studied. Materials and Methods: The synthesis was performed by the AC Plasma electrolytic Oxidation (PEO) in a calcium acetate and sodium phosphate containing electrolyte followed by hydrothermal treatment at different pH values. SEM, EDS and XRD were employed to characterize the produced surface layer.

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Results: All the oxidized coatings contained Ca and P as well as Ti and O, and the porous coatings were made up of anatase, rutile and hydroxyapatite. After hydrothermal treatment, the hydroxyapatite was precipitated on the surface of the sample plate obtained by PEO and the hydroxyapatite thickness was about 15 μm. Conclusions: The combination of PEO and hydrothermal treatment allows production of porous titania surface enriched with hydroxyapatite having the technological thickness suitable for dental surgery and favoring better osseointegration.

Poster Presentation No. 80 The internal fit of metal-ceramic restorations prepared by different methods

Duygu Saraç, Necati Kaleli Ondokuz Mayis University, Department of Prosthetic Dentistry, Turkey

Purpose: The aim of this study was to compare the internal fit of metal-ceramic restorations prepared by conventional casting, milling, direct metal laser sintering (DMLS) and selective laser melt- ing (SLM). Materials and Methods: Forty-eight, three-unit fixed partial denture shaped specimens were prepared on a bronze die for each group which represents prepared left mandibular second premolar and second molar. Twelve conventionally casted, 12 milled, 12 direct metal laser sintered and 12 selective laser melted cobalt-chromium (Co-Cr) metal frameworks were prepared, then opaque and veneer porcelain material were applied. All specimens were cemented using self-adhesive resin cement. After embedding the specimens into acrylic moulds, all specimens were abraded bucco-lingually to middle section. Internal gap of the restorations were measured on mesial, distal and occlusal area by using stereomicroscope. Data were statistically analyzed by one-way ANOVA (α = 0.05). Results: A significant difference were found between the groups of conventional cast, milling, DMLS and SLM (p > 0.05). SLM group showed the better internal adaptation than other groups. Conclusions: All samples showed a clinically acceptable internal adaptation. All methods were found to be reliable in terms of internal adaptation. On the other hand, laser-sintering groups showed better internal adaptation, which is a result of high accuracy of combining micro-particles together.

Poster Presentation No. 81 Analysis of abutment convergence angles by 3D processing with stereovision

In-Sung Yeo Seoul National University, Korea

Purpose: This study investigated axial wall convergence angles of abutment teeth using a computerized image processing with stereovision technology. Materials and Methods: Three dimensional (3D) coordinate points were predicted from two dimensional (2D) images. Distances and angles between the points were calculated. Two examiners measured axial wall convergence angles for seven artificial abutment teeth, based on the stereovision images. The measured values with this stereovision-based method (SVBM) were compared to those with the traditional tracing-based method (TBM). A wax model with two different slopes were made (n = 5). The slope angles of the model were measured by both methods, and the differences between the measured and real values were evaluated. Results: From the intra-class correlation coefficients, the intra-examiner and inter-examiner reli- abilities were shown to be excellent for both methods. However, significant differences between the measured and real values were found in the measurements of the wax models with the TBM. The

99 39th Annual Conference of the European Prosthodontic Association differences were not significant in case of the SVBM. Conclusions: This study indicated the limitation of 2D analysis for a 3D object by showing more accurate measurements by SVBM than by TBM.

Poster Presentation No. 82 Manufacture of conventional crowns using a chilled acrylic resin system: Innovation

Marcondes Oliveira Federal University of Bahia, Brazil

Purpose: Building conventional crowns and fixed bridges of reasonable quality requires scientific knowledge and careful clinical procedure. Perfect temporaries, mouldings and moulds are the result of careful and precise preparation of the remaining dental material, gingival retraction with a cord and use of suitable elastomers. One cannot ignore evidence showing that as currently performed, this type of work is complex, unsafe, time demanding, stressful and not very productive. However, contrary to established practice, it is a constant desire of prosthodontists to have uncom- plicated clinical routines that yield conventional prostheses of exceptional quality. Materials and Methods: We developed a highly precise system to make crowns using chilled acrylic resin for moulding, which yields high precision moulds, models, casting patterns and metal copings based on simple, safe and reliable clinical steps. Results: The system presents the following advantages: a) no need to use a cord in the gingival sulcus; b) no need to use elastomers; c) mouldings may be made in four to five days after the temporaries; d) mould corrections are possible; e) acrylic resin is inexpensive; f) chilled acrylic has a long handling time; g) mouldings may be corrected. Conclusions: The innovative procedure which uses chilled acrylic resin causes no stress or tension.

Poster Presentation No. 83 Effect of varying core thicknesses and artificial aging on the colour difference of different all-ceramic materials

Julide Ozen, S. Dikiciler, I. Yamaner University of Istanbul Aydin, Prosthetics Dentistry Department, Turkey

Purpose: Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level aesthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and colour change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the colour stability of three all-ceramic systems. Materials and Methods: Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colours of the samples were measured with a spectrophotometer and the colour parameters (L*, a*, b*, DE) were calculated according to the CIE L* a* b* (Commission Internationale de L’Eclairage) colour system before and after aging. Results: The effects of aging on colour parameters were statistically significant (p < 0.001), regardless of core thickness. For all systems, the CIE a* values increased as the thickness of the core increased. Conversely, such increases in core porcelain thickness were correlated with decreasing CIE L* and b* values. Core thickness had a statistically significant effect on colour change among the groups. Conclusions: Different core thicknesses (from 1.0–0.5 mm) and artificial aging affected colour stability of the all-ceramic materials tested.

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Poster Presentation No. 84 Effect of placement techniques on correct positioning of veneers during cementation

Pinar Ates, Heval Şahan, Erhan Çömlekoglu Ege University, School of Dentistry, Department of Prosthodontics, Izmir, Turkey

Purpose: Various cementation accessories and instruments may be used to locate veneer restorations properly during cementation. The aim of this study was to evaluate the effect of different veneer placement techniques on correct positioning of veneers during adhesive cementation. Materials and Methods: Veneer type preparation with a mini-chamfer margin (0.6 mm) was made on a phantom tooth of maxillary right central incisor. The impression was made with a polyvinylsiloxane impression material (Affinis Precious) and die models (N = 30) were made of epoxy resin (EP85-215). Thirty veneer restorations were manufactured from a glass-ceramic material (e.max CAD) by a CAD/CAM system (Cerec 4.2). They were checked for marginal adaptation, glazed and divided into 3 placement groups. In the first group, veneers were picked-up and held using a placement applicator with an adhesive tip (Optrastick) during cementation and polymerization, while a dental cotton tweezers were utilized for the same purpose in the second group. In the third group, veneers were placed bidigitally and then polymerized (Bluephase N). Digital photographs were taken from each specimen before cementation while the veneers were securely seated on the dies. Secondary identically aligned photographs were also obtained after cementation and the difference per each die was recorded using digital substraction software. The data were statistically analyzed (ANOVA, p < 0.05). Results: Mean values (mm2 ± SD) were as follows: G1: 2.2 ± 0.6; G2: 3.7 ± 0.7; G3: 0.7 ± 0.4. G3 demonstrated significantly lower misfit values than other groups (p < 0.05). Conclusions: Holding veneers bidigitally during cementation may be the most reliable method in terms of proper placement.

Poster Presentation No. 85 Influence of oxygen-inhibited layer on bonding performance of adhesive systems

Akimasa Tsujimoto Nihon University, School of Dentistry, Japan

Purpose: This paper investigates the influence of the oxygen-inhibited layer on the surface properties and bond strength of different adhesive systems. Materials and Methods: The bonding systems used in this study were Scotchbond Multipurpose (SM), Clearfil SE Bond (SE) and Scotchbond Universal (SU). Adhesives were applied to the bo- vine enamel and dentin, and light irradiated, and the oxygen-inhibited layer was either retained or removed. Surface free-energies were determined by measuring the contact angles of tested liquids on the cured adhesives. Enamel and dentin bond strength of the adhesives with and without oxygen-inhibited layer were measured. Ultra-structural observation of the resin-dentin and resin- enamel interface was made by scanning electron microscopy. Results: The total surface free-energy values, polarity force and hydrogen-bonding force of cured adhesives with an oxygen-inhibited layer were significantly higher than those of cured adhesives without an oxygen-inhibited layer. The bond strength of SM and SE bonded to enamel and dentin showed no significant differences between specimens with and without the oxygen-inhibited layer. However, the bond strength of SU with the oxygen-inhibited layer was significantly higher than the without the oxygen-inhibited layer to both enamel and dentin. Conclusions: The results of this study indicated that the surface free-energy characteristics of the oxygen-inhibited layer of dental adhesives were different depending on the type of adhesive. In addition, the presence of the oxygen-inhibited layer of single-step self-etch adhesive promotes stronger bonding, unlike the other types of adhesive system.

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Poster Presentation No. 86 Flexural strength of fixed dental prosthesis with and without fibre reinforcement

Monika Burdinyashka, Schweyen R., Setz J., Arnold Ch. Martin Luther University Halle-Wittenberg, Centre for Dentistry and Oral Medicine, Department of Prosthodontics, Germany

Purpose: Fibre reinforcement is recommended to enhance the stability of temporary bridges. The aim of this study was to evaluate the flexural strength of three-unit fixed dental prosthesis (FDP) with and without fibre reinforcement. Materials and Methods: Three-unit FDPs were fabricated on a standardized master pattern with a premolar and molar using a deep-drawn film. Five specimens were produced with the following materials, respectively: Structur Premium QM (SP), SP with Grand Tec (SPG), Tuff-Temp (TT), TT with Dentapreg (TTD), Luxatemp (LT) and Luxatemp with Ribbond (TTR). All specimens underwent artificial ageing (mechanical loading 240,000 cycles, thermal undulation 5°/55 °C 5,000 cycles). To measure flexural strength, all specimens were loaded in a 3-point bending test rig until fracture in a universal testing machine (Zwick Roell Z010, preload 1 N, v = 1 mm/min). Statistical analysis was performed using SPSS 20.0 (Mann-Whitney U-test, p < 0.05). Results: Highest flexural strength was found in specimens made of SP (1902 N ± 938 N). Lowest values were found in specimens made of TTD (1394 N ± 216 N). The values of the FDPs with and without fibre reinforcement did not differ in a significant way (p > 0.05). Conclusions: Fibre reinforcement did not lead to a significant increase in flexural strength. There- fore, the additional use of fibres does not seem to be recommendable for clinical practice.

Poster Presentation No. 87 Lithium disilicate. Can it be the ceramic material of choice?

Marina Dimopoulou, Paris Ravanis, George Papavasiliou, Phophi Kamposiora Dental School of Athens, Greece

Purpose: One of the major changes in modern restorative dentistry is the evolution of all-ceramic systems. The dentist is able to achieve restorations with improved aesthetic properties. One of the most recent systems is lithium disilicate, a material which imparts to the restoration a more natural effect with properties that support the function of the stomatognathic system. In this presentation lithium disilicate will be described and analyzed through its application in clinical cases. The aim was to present the types of restorations that can be fabricated along with the material’s properties (biological, mechanical and optical). Materials and Methods: Clinical cases will be presented, restored with lithium disilicate prostheses concerning, veneers, single crowns in the aesthetic zone, combinations of veneers and crowns as well as customized hybrid implant abutments. Results: The presentation of the applications of lithium disilicate through these clinical cases illustrates the optical and biological advantages of the material. The natural appearance that provides to the prosthetic restorations and the possibility for different kinds of prosthetic solutions makes lithium disilicate a valuable treatment modality in modern dentistry. Conclusions: Lithium disilicate is a modern ceramic system. Both laboratory and clinical studies provide positive long term outcomes for use in restorative dentistry. At the same time both the dentist and the dental technician need to know in depth both the properties and limitations of lithium disilicate in order to achieve optimal performance of the restorations.

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Poster Presentation No. 88 The relationship between the dental occlusion and temporomandibular disorders

Zana Lila-Krasniqi, Kujtim Shala, Linda Dula, Teuta Pustina, Teuta Bicaj, Enis Ahmedi, Arlinda Tmava, Ljuben Guguvcevski University Dentistry Clinical Centre of Kosovo, Prishtina, Republic of Kosovo

Purpose: The relationship between the dental occlusion and temporomandibular disorders (TMDs) has been one of the most controversial topics in the dental community. Aim: to compare subjects from the group with fixed dentures, the group who present TMDs and a control group considering centric relation and maximum intercuspation and to analyze the related variables also compared and analyzed with electronic system T-Scan III. Materials and Methods: Total of 54 subjects were divided in three groups; 17 subjects with fixed dentures, 14 with TMDs and 23 controls – selection based on anamnesis – responded to a Fonseca questionnaire and clinical measurements were analyzed with electronic system T-Scan III. Occlusal force, presented by percentage (automatically by the T-scan electronic system) was analyzed in centric relation and in habitual occlusion. Results: Data were presented as mean ±SD. Kolmogorov-Smirnov test, Lilliefors test, Shapiro- Willks test were used for the distribution of the data at the numerical series. Differences in P < 0.05 were considered significant. After measurements of the differences between centric relation and habitual occlusion in the three groups were noticed varieties but the P > 0.005 it was not significant in all three groups. Conclusions: Based on the limitations of the present study, it was concluded that there are not statistically significant differences between centric relation and maximum intercuspation in the group of individuals without any symptom or sign of TMD although there was noticed the disharmonic relation between arches with overload of the force on the one side in the group with TMD and fixed dentures.

Poster Presentation No. 89 Comparative study of the mechanical properties of acrylic resin copolymers

Ayşegül Köroglu1, Onur Şahin1, Doğu Ömür Dede2, Baki Hazer3 1Bülent Ecevit University, Faculty of Dentistry, Department of Prosthodontics, Zonguldak, Turkey 2Ordu University, Faculty of Dentistry, Department of Prosthodontics, Turkey 3Bülent Ecevit University, Faculty of Arts and Sciences, Department of Chemistry, Turkey

Purpose: The aim of this study was to evaluate some mechanical properties of polymethyl methacrylate (PMMA) based denture base resins polymerized by copolymerization mechanism. Materials and Methods: Butyl methacrylate (BMA), 2-hydroxyethyl methacrylate (HEMA), isobutyl methacrylate (IBMA) and polyhedral oligomeric silsesquioxane (POSS) were added to monomers of conventional heat and microwave polymerized PMMA resin contents of 2%, 5%, and 10% by volume and polymerization was carried out. Three-point bending and impact strength tests were performed to detect transverse strength and impact strength of the resins. Data were statistically analyzed with 3-way analysis of variance (ANOVA) and Tukey HSD test. Results: According to the three-way ANOVA results of transverse strength and impact 3strength, the type of denture base material and the type and ratio of added monomer were significant (p < 0.05). Although in all study groups the copolymerization mechanism increased the value of transverse strength, only the IBM 10% and HEMA 10% conventional heat polymerized resin group showed statistically significant difference. In terms of impact strength, except POSS 5% conventional heat and POSS 10% microwave polymerized resin group, there was no significant difference between the control group and the resin groups (p > 0.05). Conclusions: In previous studies, copolymerization mechanism is proposed for the improvement of

103 39th Annual Conference of the European Prosthodontic Association the mechanical properties of the denture base acrylic resins. In the present study, copolymerization process was only effective in the transverse strength of IBM 10% and HEMA 10% conventional heat polymerized resin group. Therefore, there is a need for further studies about the monomer ratios.

Poster Presentation No. 90 Comparison of two types implant supported crowns in anterior section

Eva Hašková, Lenka Vavřičková Charles University in Prague, Faculty of Medicine in Hradec Králové, Department of Dentistry, Czech Republic

Purpose: Single tooth loss can be treated with conventional three-unit or adhesive bridges. The lost tooth can be also replaced with a dental implant. Prosthetically single tooth loss can be treated with a PFM (Porcelain Fused to Metal) crown or with an all-ceramic crown with a custom abutment from zirconoxide ceramics. Materials and Methods: Implant supported single unit crowns in the anterior section of both jaws and their complications were compared from 2010 to 2014 on Department of Dentistry of Faculty of Medicine in Hradec Kralove. Chipping, chipping off the ceramic layer to the metal coping, all-ceramic crown fracture, crown and also abutment fracture and bond failure between zirconoxide and titanium part of the abutment were considered as a complication. 705 patients with 246 all-ceramic crowns and 614 with PFM crowns were treated from 2010 to 2014. Results: There were chipping as well as chipping off the ceramic layer to the metal coping found for PFM in 2.1%. Chipping, all-ceramic crown and abutment fracture as well as bond failure between zirconoxide and titanium part of the abutment were found in 2.0% for all-ceramic crowns. No single all-ceramic crown fracture was observed. Conclusions: Under limitation of this study, the chipping off the ceramic to the metal coping in PFM crowns was caused probably by the failure of the bond between materials. The chipping was probably caused by disrespecting the patients´ occlusal concepts. To prevent all complications, it is necessary to follow all rules of crowns fabrication and the proper technology. Supported by the programme PRVOUK P28.

Poster Presentation No. 91 Treatment of an extensive maxillary partial alveolar ridge resorption with a hybrid denture

Nurten Baysal, Simel Ayyildiz, Cumhur Sipahi Gulhane Military Medical Academy, Kecioren, Ankara, Turkey

Purpose: The aim of this case report was to restore an alveolar ridge defect of the right maxillary posterior arc with a partial screw retained hybrid denture. Materials and Methods: Case Report: A 49-year-old male patient was referred to the clinic for the restoration of his implants with a fixed partial denture located in right posterior maxilla. The dental history included a long process of treatment including three major surgeries on that region of maxilla. In clinical examination it was seen that the teeth 14,15,16,17 were extracted and two implants were placed surgically in 14 and 17 teeth region. Also, the alveolar ridge and tuber maxilla were severely resorbed and as a result of this resorption the interarc distance was increased consider- ably at this region. Results: For this reason, it was decided to fabricate a hybrid denture to meet the aesthetic and functional expectations of the patient. Due to the size of the defect an acrylic resin based hybrid denture was fabricated to decrease the weight of the prosthesis.

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Conclusions: After a complicated treatment process, because of the surgery complications, the patient was satisfied with the result of the denture.

Poster Presentation No. 92 Aesthetic rehabilitation of maxillary anterior teeth with full porcelain restoration

Nurten Baysal, Simel Ayyildiz, B. Filiz Erol, Cumhur Sipahi Gulhane Military Medical Academy, Kecioren, Ankara, Turkey

Purpose: The aim of this case report was to restore anterior teeth with full porcelain fixed partial dentures to provide an aesthetic outlook for patient. Materials and Methods: Case Report: A 32-year-old male patient was referred to the clinic with the complaint of poor aesthetics of maxillary anterior teeth. The patient had large composite restorations on both of the central incisors, which were done more than one time, and there was also dental crowding between the anterior teeth. The patient refused to have orthodontic treatment because of the long treatment time. And it was seen that dental crowding in the patient can be repaired enough by only restoring central incisors. Results: It was decided to restore central incisors with full porcelain restorations to gain a better aesthetics. Conclusions: The patient was very satisfied with the result and had no complaints at the following control after six months.

Poster Presentation No. 93 Rehabilitation of palatal defects with new surgical and hollow-definitive obturators

Pravinkumar Patil International Medical University, Jalan Jalil Perkasa, School of Dentistry, Kuala Lumpur, Malaysia

Purpose: To describe new obturator designs and fabrication techniques with clinical success rate. Materials and Methods: This paper describes two different techniques of fabrication of surgical, interim and/or definitive obturator. 1. Surgical obturator technique describes the fabrication procedure of the prosthesis that restores post-surgical palatal defect with original anatomic form and shape. Satisfaction levels of 15 patients were recorded on visual analogue scale (VAS). Four different prosthodontists visually evaluated facial asymmetry in patients at 6 months recall and their average perception on VAS was recorded. 2. Hollow obturator technique describes the laboratory procedure how to fabricate closed-hollow obturator bounded by the heat polymerized acrylic resin with uniform wall thickness. The pre-shaped wax-bolus was incorporated during packing procedure to achieve hollow space in the prosthesis. Total 10 patients were treated with this technique. Patient-satisfaction-level was recorded on VAS and the obturators were evaluated for fluid leakage after 1 year of recall. Results: 1. Surgical obturator: Patients’ satisfaction level on VAS ranges between 71% and 92% (average 81%). The average score of 4 different prosthodontists for facial asymmetry in patients at 6 months of recall varies between 69% and 95% (average 85%). 2. Hollow obturators: Patients’ satisfaction level on VAS ranges between 76% and 93% (average 87%). 90% of obturators did not show fluid leakage after 1 year. Conclusions: The surgical obturator fabrication technique restoring original tissue form provides acceptable post-surgical aesthetics. Hollow obturator with uniform wall thickness provides acceptable patient satisfaction and resistance to fluid leakage.

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Poster Presentation No. 94 Articular-eminence measurements performed by conventional and three-dimensional method

Josip Kranjcic1, Slaus Mario, Catlak Zlatko, Persic Sanja, Vojvodic Denis 1University of Zagreb, School of Dental Medicine, Croatia Croatian Academy of Sciences and Arts, Anthropological Centre, Zagreb, Croatia University of Zagreb, School of Dental Medicine, Croatia University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Croatia

Purpose: Articular eminence (AE) morphology could be expressed by dimensions and angles measured by different methods. The aim of this study was to compare conventional two-dimensional with three-dimensional laser method. Materials and Methods: The study was carried out on 20 human dry skulls (18 to 65 years) from medieval and contemporary period. Measurements were performed on sections (real and virtual) through the AE silicone impressions (lateral-medial) using two-dimensional and three-dimensional (laser) digitalization. AE inclination (two methods) in relation to the Frankfurt horizontal, AE height and the length of curved line (highest to the lowest AE point) were measured. Results were statistically analyzed with significance level of 0.05. Results: Although small differences existed between AE measurements performed by conventional and three-dimensional laser technology, most of obtained differences were not statistically significant (p-values: AE inclination 0.003 to 1.0; AE height 0.012 to 1.0; curved line length of 0.115 to 1.0). Differences between AE inclination values measured by “best fit line” method and “fossa roof – eminence top” method were statistically significant (p < 0.001). Conclusions: Silicone impressions eased the procedure and retained accuracy for AE measurements. Differences for most of the performed measurements by conventional and three-dimensional method were not significant, thus indicating same reliability of the used methods. AE values by “best fit line” method were higher than by “fossa roof – eminence top” method no matter which measuring method was used. These values are more affected by the eminence height thus representing simplified but actual condylar path significant for adjustment of articulators.

Poster Presentation No. 95 The assessment of clinical alterations in the bearing area of complete denture wearers

Ganimet Deda, F. Perijuci, M. Kuçi, T. Bicaj, F. Asllani, E. Ahmedi University Prishtina, Republic of Kosovo

Purpose: Complete dentures are the best prostheses in human body, fulfilling functional and aesthetic requirements. Aim was to asses clinical alterations in the bearing area of complete denture wearer, through a specific case report with rare sever alterations. Materials and Methods: A patient, 56-year-old female, wearing complete upper and lower denture for 25 years, came for a check up due to the fact of “not being able to wear upper complete denture” for the last two years. After routine examination extra-orally and intra-orally, it was noted sever change on the bearing area on the vestibular site, all along of the alveolar ridge of the upper jaw. Changes were present as chronic hyperplastic alterations, forming double and in some regions triple vestibules (epulis fissuratum). Initially, in consultation with oral surgeon, it was planned and done vestibuloplasty with secondary healing of epithelium using immobilization of the tissues by old complete denture relined with zinc oxide paste, fixed by two mini-screws palatal for 10 days. New complete denture was fabricated within two next days, after total epithelization of mucosa. Results: After surgical treatment and new complete dentures, with excellent fit and occlusion, and also with regular and obligatory follow-ups, patient was completely satisfied functionally and aesthetically.

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Conclusions: Patient had complete dentures for 25 years, and was satisfied for 23 years. Last two years she had slight problems and complains, but never had a check-up, until she could not wear the denture anymore. It is mandatory a routine check-up of complete denture wearers including when symptoms are absent.

Poster Presentation No. 96 Efficacy of diode laser and desensitizing agent on prepared teeth

Haluk Baris Kara, Umut Cakan, Burcu Yilmaz, Pelin Inan Kurugol Istanbul Medipol University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Dentine sensitivity is a common symptomatic condition which may occur after crown preparation. The purpose of this study was to compare the effects of diode laser and a commercial desensitizing agent on sealing the dentinal tubules of prepared teeth. Materials and Methods: In this split-mouth study, for each patient, prepared teeth in one quadrant were individually irradiated by diode laser at consecutive intervals and in the symmetrical quadrant a small amount of desensitizer was applied onto the prepared teeth by small cotton pellets. The surface was then dried by applying a stream of compressed air until the fluid film had disappeared and the surface was no longer shiny. At the control group, no treatment was performed on the prepared teeth. Temporary crowns were fabricated and cemented onto the prepared teeth using non-eugenol temporary cement. The effectiveness of both applications was assessed by one examiner who was not aware of the type of treatment applied at three examination periods; first day, first week and second week after treatment by mechanically sounding the finishing line circumferentially and the preparation surface mezio-distally and bucco-lingually through VAS scores. Results: Regarding the first day, first and second weeks, VAS scores of the control group were statistically higher than in diode laser and desensitizing agent groups (p < 0.017). The difference between VAS scores of the diode laser and desensitizing agent groups was statistically insignificant (p > 0.05). Conclusions: Both methods may be considered as effective in decreasing dentin hypersensitivity after tooth preparation.

Poster Presentation No. 97 Four maxillary incisors’ selection using interalar width

Nasr Mohamed Ahmed Elsheikh The National Ribat University, Sudan

Purpose: To measure interalar width and relate it to the overall width of the four maxillary incisor teeth. Materials and Methods: It was a descriptive cross sectional study conducted among Khartoum University students. Participants were selected following certain criteria: all maxillary teeth present; no diastemas, Angles Class I Relationship, Skeletal Class I Jaw Relation, regular intact anterior teeth, teeth free from fillings, no history of orthodontic treatment. Severe attrition and caries cases were excluded. Subjects with a history of congenital anomaly, trauma or facial surgery were also excluded. After signing a written informed consent, 114 students were included in the study. Ir- reversible hydrocolloid (Alginate) was used to obtain maxillary impressions that were poured immediately with dental stone. The Interalar Width (I.A.W) and the overall width of the four maxillary teeth were measured for each subject. Measurements were carried out using an electronic digital calliper (Narex – Czechoslovakia), to the nearest tenth of a millimetre and coefficient correlation (r-factor) was obtained.

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Results: Forty five males and 69 females, ranging from 25–46 years old were enrolled in this study. The relationship between the overall widths of the four maxillary incisors was highly significant in all subjects (P-value was 0.000). In males (P-value was 0.103) and in females (P-value was 0.051). Conclusions: Overall width of four maxillary incisors may be estimated by dividing interalar width by factor 1.4.

Poster Presentation No. 98 Associations of gonial angle with age, gender and dental status

Ab Ghani Siti Mariam, Rohana Ahmad MARA University of Technology, Faculty of Dentistry, Centre for Restorative Dentistry Studies, Ma- laysia

Purpose: The aim of this proposed study is to create a preliminary database of gonial angle (GA) sizes of the Malay populations and to find associations of GA size with age, dental status and gender. It was hypothesized that GA will increase with age and the status of dentition as it progresses from dentate to edentulousness. Materials and Methods: More than 600 orthopantographs (OPG) were retrieved from Faculty of Dentistry, UiTM dental records and filtered to achieve equal number of cases of 200 male and 200 female subjects with similar subgroups of 50 fully edentate, 50 partially dentate and 100 dentate subjects. The dentate subjects were further divided into 50 middle-aged group (40-year-old and above) and 50 young adult group (20–30 years old). The GA was measured on the OPG and correlated with age, gender and dental status. Results: There was a general trend of increase in the size of GA as the dental status goes from dentate to edentate but the increase was not significant. However, there was a significant difference in the size of GA within the dentate patients as age increases but no differences were detected between genders. Conclusions: A preliminary database on the mean sizes of GA for Malay population has been established which could be used as future reference. This study also proved the hypothesis that GA size increases with age which could be due to the reduction of muscles strength as a result of aging. The state of dentition did not seem to play a significant role in determining the size of GA.

Poster Presentation No. 99 The benefits of clenching, the sports perspective

Hendrik Lieshout PRO Rotterdam, The Netherlands

Purpose: Clenching can cause muscular disorders, increase pain, fracture teeth and increase tooth wear. Normally it is considered destructive and it is discouraged and/or treated. In the world of sports clenching could be beneficial. This review of the literature tries to determine what the relationship is between a good and stabile occlusion, clenching and its benefits. Materials and Methods: A comprehensive literature search has been carried out on Pubmed (Med- line). After screening all the retrieved titles and abstracts the included articles were read and analysed. Results: The source literature on this topic is not conclusive and at some points contradictory. Occlusion, muscle contraction and an enhanced performance in sports could be related in three areas. Clenching could enhance the strength and force necessary for a short instant. Second: a good and stabile occlusion could be beneficial for a stabile posture and increases the sway area. Third: in contact sports and sports with high speeds, contraction of the muscle groups in the head

108 39th Annual Conference of the European Prosthodontic Association and neck area decreases concussions and further brain damage due to less head accelerations. Conclusions: Enhanced muscular strength could be useful during performance of various athletic sports. It is still unclear whether a stabile occlusion is necessary for a stabile posture. The literature is contradictory. Brain damage is unfortunately a common injury in many sports. Good protection, tactics and training, like clenching, decreases the outcome of a collision or an impact. Further research is necessary to uncover all the factors that can play a role in this interaction.

Poster Presentation No. 100 Denture cleansers’ effect on retention of candida and roughness of denture teeth

Sule Tugba Deniz1, Doğu Ömür Dede, Onur Şahin, Ayşegül Köroğlu, Nurdan Karacan 1Biruni University, Istanbul, Turkey Ordu University, Bulent Ecevit University, Ankara University, Turkey

Purpose: The purpose of this study was to investigate the effect of denture cleansers on surface roughness and Candida albicans formation of denture teeth materials. Materials and Methods: 40 disc-shaped specimens were prepared for each type of denture teeth material (SrVivodent, PMMA; Vitapan, reinforced-PMMA; SrPhonares II, composite resin). The surface roughness values were measured by using a profilometer. Specimens were immersed in distilled water and various denture cleansers (NaOCl, Correga, Rapident) for 8 hours a day during one month test period. After one month storage the final measurements were made for surface roughness and then the specimens were ultrasonically sterilized for Candida albicans formation. The optical density of the Candida albicans ATCC (90128) stock solution was adjusted to a 0.5 MacFarland solution. 1 ml yeast suspension was incubated with the sample for 48 h at 37 °C. After incubation, the microbial colony count of each plated denture teeth was quantified by the eye count- ing method and the logarithm of colony forming units (CFU) per ml was then calculated. The data was statistically analyzed using two-way ANOVA, Tukey’s test and Paired sample t-test. Results: Surface treatment technique was effective on surface roughness values. The type of tooth material and its interaction with surface treatment technique were effective on candida formation values (p < .05). SrPhonares treated with Corega had significantly higher Candida formation (3760 ± 3031 Cfu/mm) than in the control group (p < .05). Conclusions: Denture cleaners would be effective on surface characteristics of denture teeth materials so that clinicians should be careful while recommending alkaline peroxide cleaners.

Poster Presentation No. 101 Minimally invasive approach in prosthodontics: Prosthesis with partial anchorage

Layla Assila, Hicham Soualhi, Amal El Yamani Faculty of Dental Medicine, Rabat, Morocco

Purpose: The objective of this work is to highlight this minimally invasive treatment and its update. These are ceramic veneers, aesthetic inlay-onlays, and adhesive bridges that will be described and illustrated through clinical cases. Materials and Methods: The fixed prosthesis with partial anchorage is part of a conservative approach of microdentistry aiming to optimize the dental tissue economy. A principle respected in the treatment of clinical cases through the study of decision parameters, and through the principles of preparation and development of bonding composites. Results: Advances in micro-dentistry allow us to design so-called conservative prostheses which preserve the maximum residual healthy dental tissues, while meeting the mechanical, biological, functional and aesthetic requirements of prosthetic restorations.

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Conclusions: The collection of current knowledge about the different types of fixed prosthetic restorations called minimally invasive, broadens the range of therapeutic options and thus meets the requirements and demands of our patients who are sincreasingly targeted.

Poster Presentation No. 102 Composition of dentin after different surface treatments and bonding application

Meryem Gülce Subaşı1, Necla Demir2, Tevfik Yavuz3, Muhammet Karcı2, A. Nilgün Öztürk2, Hamdi Şükür Kılıç4 1Istanbul Aydın University, Faculty of Dentistry, Department of Prosthodontics, Turkey 2Selcuk University, Department of Prosthodontics, Turkey 3Abant Izzet Baysal University, Department of Prosthodontics, Turkey 4Selcuk University, Department of Physics, Turkey

Purpose: To evaluate the elemental composition changes of dentin surfaces after surface treatments and bonding application. Materials and Methods: Forty eight freshly extracted human molar teeth were embedded in acrylic resin and 1.5 mm tooth structure was removed under water cooling using a low speed sectioning machine. They were divided into three groups according to surface treatments (control, Er:YAG laser, Femtosecond laser) (n = 16). Then, each surface treated dentin surfaces were divided into two subgroups according to bonding agent (Clearfil SE Bond, Protect Bond) (n = 8). EDX analysis was performed for each specimen both after surface treatment and bonding application. Elemental composition (Ca, O and P) values were analyzed by two-way analysis of variance and Tukey HSD tests. Results: For Ca element, bonding type (p = 0.015), for P element surface treatment (p = 0.008) and bonding type factors (p = 0.002) were found significant. Conclusions: Considering the elemental composition changes of dentin, femtosecond laser as a surface treatment option instead of Er:YAG laser treatment and Clearfil SE Bond as a bonding agent should be recommended.

Poster Presentation No. 103 Treatment alternatives for full edentulism – conventional versus implants – imagistic assessment

Marina Melescanu-Imre, Ana Maria Tancu, Cristina Preoteasa, Madalina Vuza, Elena Preoteasa University of Medicine and Pharmacy Carol Davila, Bucharest, Romania

Purpose: Treatment planning for conventional complete denture, overdenture on implants or fixed implant restoration is a complex decision for most prosthodontists in full edentulous cases. Our goal is to highlight some morphological aspects due to severe bone resorption assessed through imagistic methods in order to choose the most appropriate treatment alternative. Materials and Methods: Pilot study conducted on full edentulous or in imminence to become edentulous patients. Patient’s anatomical and functional status as well as treatment goal to have fixed or removable prosthesis must be considered. The assessment of bone level required through clinical and imagistic measurements – panoramic and CBCT to determinate the height of the residual alveolar bone to establish the most appropriate therapeutic alternative. Results: For the upper jaw, bone level vertical and horizontal dimensions are a factor to be considered. Vertical bone resorption requires extensive surgical procedures, so most appropriate removable solution. If vertical resorption is nonexistent or limited, there is no buccal resorption recommendation on fixed restoration. In case of horizontal resorption – when resorbed, one option is to

110 39th Annual Conference of the European Prosthodontic Association graft the missing buccal. In the mandible, where the atrophy is usually severe, are recommended fixed prosthetics on implants on non atrophic ridge, removable prosthetics on implants for moder- ate resorption and the actual “standard of care” overdenture on 2 implants. The last option for atrophic mandible is sustained only by placing complete denture or implants of narrow diameter. Conclusions: The predictability and success of implant therapy in edentulous patients is correlated with bone resorption. The treatment planning evaluates this, in order to recommend fixed or removable prosthesis, and due to high resorption rate, especially in mandible, the conventional denture remains the only solution for edentulous patients.

Poster Presentation No. 104 Colour in zirconia-base restorations

Farhad Tabatabaian, Minoo Mahshid, Habib Mirzaei Amirabad University of Medical Sciences, Dental School of Shahid Beheshti, Tehran, Iran

Purpose: Recently the use of zirconia crown due to the appropriate biocompatibility and high strength has been increased in restorative dentistry. Advanced CAD/CAM systems have been well established in prosthodontics in order to fabricate zirconia restorations. From aesthetic point of view, zirconia crowns have advantages compared to metal ceramic crowns, where discolorations are caused by the metal margin and its show beyond the gingiva. However the requirement to achieve natural looking restorations is still challenging and the shade matching of the restorations with the natural dentition is difficult due to the complex optical characteristics of natural teeth. Materials and Methods: In this presentation, colour in zirconia-base restorations is described based on the literature, while the colour measurement, perception threshold, shade selection, measuring devices, and shade reproduction are demonstrated. Results: Factors affecting the target colour include: dental core (background), cement, zirconia core, porcelain layers of dentin and enamel, glaze, and manufacturing processes. Conclusions: Shade selection in zirconia-base restorations seems to be unpredictable, because of the different factors which affect the target colour of restoration.

Poster Presentation No. 105 Implant treatment using electroformed double crowns for jaw bone reconstruction

Shoji Hayashi, Sugiyama Shuta, Koujirou Shimura, Go Tobayama, Ryosuke Fukue Kanagawa Dental University, Yohohama city Kanagawa, Japan

Purpose: After tumour resection, implant treatment with jaw bone reconstruction using iliac bone grafting was performed. Implant prosthetic treatment was performed using electroformed double crowns to recover aesthetics and functionality, and we report the findings on long-term observation. Materials and Methods: The patient was a 31-year-old female, who visited our clinic with a chief complaint of masticatory disorders due to marked mobility of the teeth at 35, 34, 41, and 42. Tooth extraction and biopsy were simultaneously performed, and after tumour resection under a diagnosis of fibrous osseous, reconstruction surgery was performed using titanium mesh trays and iliac bone. Four implants were placed in the iliac bone grafting area, and secondary surgery was performed. After provisional restoration insertion, patient-removable electroformed double crowns were inserted in June 2005. Results: Ten years after superstructure insertion, no abnormal findings were noted around implants, and panoramic radiography showed a favourable clinical course. Although discoloration of the resin plate area of the superstructure was observed, the retention force of the electroformed outer crowns was appropriate.

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Conclusions: After jaw bone reconstruction, the implant placement in intended area and direction is impossible due to the morphology and characteristics of the jaw bone in some cases. In the present case, we produced a patient-removable superstructure, considering hygiene and functionality. Because the retention force has been maintained for 10 years, it was confirmed that the excellent fit of electroformed double crowns is reliable. Furthermore, it was considered that good hygiene prevented implantitis.

Poster Presentation No. 106 Clinical comparing of casted and CAD/CAM manufacture implant-supported bar substructures

Emre Seker, Emre Mumcu, Merve Kayis Esogu Faculty of Dentistry, Department of Prosthodontics, Eskisehir, Turkey

Purpose: The use of bar retainers in conjunction with implants is commonly used for the rehabilitation of edentulous patients. Materials and Methods: This case report presents the difficulties encountered in clinical and laboratory stages in two different patients and aims to guide clinical practice. Results: Implant retained bar substructures are constructed by CAD/CAM or casting techniques using various dental alloys. Conclusions: These two different approaches vary from impression stage to final restoration.

Poster Presentation No. 107 A maxillary second premolar with extraction indication: Five-year-survival after restoration

Ediz Kale, Aslıhan Koroglu, Osman Fatih Arpag, Mehmet Gökhan Tekin Mustafa Kemal University, Faculty of Dentistry, Hatay, Turkey

Purpose: To present a five-year-survival of a preserved maxillary second premolar although indication for extraction. Material and Methods: Case Report: A middle-aged male came to our clinic with a fractured maxillary right second premolar. Clinical examination revealed absent crown portion of 2/3’rds and 3ra- diological evaluation showed endodontic treatment free of apical pathology. The fracture line was more than 3 mm under the lingual gingiva. Acceptable oral hygiene with no sign of gingivitis was evident. According to the patient’s history the tooth had been successfully treated with canal-root treatment and an MOD amalgam filling was applied. After 5 years of service the filling had fractured along with the functional cusp of the tooth and within 5 days the patient had visited a dental clinic. An extraction indication was assessed but the patient insisted on any treatment but extraction. Considering the good oral hygiene a custom-cast post-core restoration was planned. The tooth was prepared and periodontal dressing was applied on the axial wall of the lingual marginal gingiva. Af- ter healing of the soft tissue a model of the post-core restoration was prepared in-situ using model- ling resin. A custom cast-metal post-core was fabricated and cemented. Abutment preparation was done and conventional full-coverage porcelain-fused-to-metal crown completed. Results: The patient experienced no problem regarding the treatment and managed to use his natural tooth for 5 years more until extraction due to slight pain and apical pathology. Conclusions: In certain conditions extraction may not be the most right option even if indicated. Sometimes trying to preserve anyway may prove the best.

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Poster Presentation No. 108 Interdisciplinary management of anterior dental and soft tissue aesthetics: A case report

Emre Seker, Basak Kusakci Seker Esogu Faculty of Dentistry, Department of Prosthodontics, Eskisehir, Turkey Esogu Faculty of Dentistry, Department of Periodontology, Eskisehir, Turkey

Purpose: Dental aesthetics has become a popular topic among all disciplines in dentistry. Espe- cially the anterior aesthetic region requires the cooperation of each dental discipline. Materials and Methods: This case report describes an interdisciplinary approach to the diagnosis and management of a 46-year-old female patient complained of the maxillary and mandibular central incisors diastema and hypersensitivity. The patient also had gingival recession on the maxillary both laterals and mandibular right canine. First of all maxillary labial and mandibular lingual frenectomy surgery has driven. In the next step, for the maxillary right and left lateral, subepithelial connective tissue graft; for the mandibular canine, free epithelialised gingival graft was planned. After periodontal treatment finished the definitive treatment plan included closing the space between maxillary incisors and mandibular incisors with zirconia retained porcelain restorations. A circumferential 1 mm width of chamfer margin was prepared for bridge restoration of maxillary and mandibular anterior site. To determine the adequate tooth length and appearance, phonetics, tooth proportion and colour were evaluated. Results: The restorations were controlled and formed in order to obtain optimal proximal and occlusal contact and ideal gingival contour. Even contacts at maximum intercuspation and proper anterior guidance of the maxillary central and lateral incisors were made. The patient was satisfied with the aesthetic and functional outcomes of these treatments. Conclusions: If a clinician prefer an interdisciplinary based approach to restore anterior aesthetic problems from the diagnosis to the whole treatment, final restoration will capture all aesthetic sense.

Poster Presentation No. 109 Maxillary obturator prosthesis fabricated with different techniques: Case reports

Tulga Ayca, Ersan Celik, Dogu Omur Dede Ordu University, Faculty of Dentistry, Turkey

Purpose: Congenital or acquired maxillary defects cause various aesthetic and functional problems. Maxillary deficiency can be prosthetically restored with an obturator. These case reports aim to show the different types and designs of obturators fabricated with different techniques used in the rehabilitation of maxillary defects. Materials and Methods: We present prosthodontic rehabilitation of three patients who had maxillary defects, two of them with the acquired palatal defects and the other with congenital cleft lip and palate. In case 1, a 46-year-old woman underwent surgical removal of unilateral hard and soft palate squamous cell carcinoma. In case 2, a 37-year-old woman had a congenital cleft lip and palate and underwent surgical operation for lip but not palate. In case 3, a 20-year-old woman underwent surgical removal of unilateral hard and soft palate because of an aggressive odontogenic myxoma. Three different techniques were used to fabricate maxillary obturators for the rehabilitation of maxillary defects. Results: The final prostheses provided good chewing and speech functions. The patients were satisfied with the maxillary obturator prosthesis. Conclusions: Unfortunately, the three patients were too young to use these prostheses. But due to the youth, their skill and adaptation might have been useful in their successful treatment. However, different patients present with unique problems and need to be treated individually.

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Poster Presentation No. 110 Ceramic mini veneers: A conservative approach for smile enhancement

Georgia Kalantzopoulou, Konstantinos Tsoutis1, Vasilios Chronopoulos2 1National and Kapodistrian University of Athens, Greece 2University of Griffith, Restorative Dentistry, Australia

Purpose: Patient demands for better aesthetics in a conservative way have increased nowadays. With the advent of new adhesive techniques and restoration materials, minimally invasive restorations could be utilized to enhance patients’ smile. They aim to achieve superior aesthetic results as they blend naturally into the dentition and to maximize the preservation of tooth structure as well. In this poster, clinical cases with aesthetic defects such as fractured incisal edges, open diastemas or slightly malpositioned teeth restored with ceramic mini veneers will be presented. Materials and Methods: After carefully designed case study and with selective, minimum tooth reduction, small pieces of thin veneers were bonded to the preserved enamel. Results: The clinical evaluation indicated that in selective cases non-invasive veneers are an efficient treatment solution with optimal aesthetic outcome. Conclusions: Restoration in these case series represented excellent clinical results, with high optical properties. Tooth structure preservation and high bond strength are their main advantages. Adhesion, finishing and polishing remain critical clinical procedures in order to achieve the desired result.

Poster Presentation No. 111 Restorative challenges of implants in the aesthetic zone

Dionysios Spyropoulos, C. Kapogianni, N. Sykaras National and Kapodistrian University of Athens, Greece

Purpose: The introduction of dental implants in prosthetic dentistry has provided us with alternative solutions regarding dental rehabilitation in edentulous patients. As nowadays osseointegration is considered a fact, interest is focused on prosthetically guided surgery in order to achieve aesthetics and eliminate complications. However, there are clinical cases where positioning of implants makes their prosthetic rehabilitation a restorative challenge. The purpose of this case series is to suggest solutions and alternative designs of implant restorations in cases of non-ideally placed implants in the aesthetic zone. Materials and Methods: Four cases will be presented, with problems of inclination, depth, position, relation with adjacent teeth and component limitations. The first three cases, regard restoration of a central incisor. In the first case, a narrow diameter implant was placed in a palatal position regarding to the adjacent teeth, resulting in a labial cantilever during function. In the second case, the implant was placed in an increased depth position. In the third case, a narrow diameter implant was placed in order to avoid bone augmentation procedures. In the last case, a narrow diameter implant was placed to restore a canine with an increased labial inclination. Results: Fabricating custom abutments allows the clinician to achieve ideal aesthetic and functional results, with long-term stability and respect of the soft tissues. Conclusions: In these cases clinician’s knowledge of the used implant system and proper collaboration with the laboratory are important prerequisites.

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Poster Presentation No. 112 Chairside fabrication of immediate complete dentures

Christina Kapogianni, D. Spyropoulos, N. Sykaras National and Kapodistrian University of Athens, Greece

Purpose: Immediate complete dentures are fabricated as provisional restorations in cases of teeth with poor prognosis and offer functional and aesthetic rehabilitation during the initial period of edentulism. The purpose of these case series is to present a method of chairside fabrication of immediate dentures. Materials and Methods: Two techniques are going to be presented. In the first technique alginate impressions of the existing teeth are made and primary casts are poured. The casts are duplicated and acrylic teeth are made based on these. The second technique is applied in cases where the patient’s existing teeth are not ideal. Primary casts are mounted and diagnostic setup of the missing teeth is done. Based on this condition acrylic teeth are made. After this, in both techniques, denture base and flanges are moulded. Results: With this procedure exact duplicates of patients’ teeth are made, so there is little change regarding aesthetics and function. As a result, transitioning from the complete dental arch to the edentulous state is made easier. This procedure is better indicated in cases where there is an almost complete dental arch with minimal occlusal and functional problems, as it applies to patients with progressive periodontal disease. This technique requires good knowledge of laboratory steps and basic principles of complete dentures fabrication. A new denture must be delivered at a later time. Conclusions: In conclusion, this method gives the clinician a fast and economic way of fabricating a patient-specific immediate denture chairside, with minimal adjustments.

Poster Presentation No. 113 Immediate loading of immediate placed implants: A case report

Neslihan Yenice, Onjen Tak, Fatih Mehmet Coskunses Kocaeli University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Patients who have suffered from severe periodontal disease are common indental practice. In this case report immediately placed and immediately loaded implant retained hybrid prosthesis for the treatment of patient who had teeth with hopeless prognosis in both jaws were presented. Materials and Methods: A 42-year-old male patient presenting mobile maxillary teeth and unsatisfactory aesthetics of the mandibular fixed prosthesis was referred to our clinic. Implant supported hybrid prosthesis were planned for both jaws. Four implants at the maxillary anterior region were placed immediately after the extractions and two tilted implants (SKY Fast & Fixed, Bredent, Send- en, Germany) were placed bilaterally to the molar regions. The same procedure was also applied for the lower jaw. Four standard abutments for the anterior implant and 35° angled abutments for the tilted implants were used following implant placement. A simultaneous, same-day, complete- arch, screw-retained acrylic based provisional prostheses were loaded. After 3 months of healing period, for the upper jaw metal-ceramic and for the lower jaw indirect composite resin (Gradia, GC, Tokyo, Japan) fused to metal restorations were produced and canine guided occlusion was achieved. Results: The patient’s aesthetic and functional expectations were achieved immediately. Neither biomechanical complications nor significant marginal bone loss were observed at 6 months follow- up. Conclusions: The major advantage of this treatment protocol is that the patient was maintained in fixed prosthesis throughout the treatment. It shortens the length of treatment period, thus a fixed restoration, supported by six implants is a satisfactory treatment option for such cases.

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Poster Presentation No. 114 Prosthetic rehabilitation of patients with maxillary defects: Two case reports

Emre Mumcu, Emre Seker, Merve Kayis Esogu Faculty of Dentistry, Department of Prosthodontics, Eskisehir, Turkey

Purpose: We aimed to maxillary defects due to congenital or developmentally acquired problems such as trauma or infection diseases or surgical treatment of benign or malignant neoplasms. Post-surgical maxillary defects predispose of several discomfortable situations. Multidisciplinary approach is necessary if optimum levels of rehabilitation are to be achieved on maxillary defects. Maxillary deficiency can be minimized or eliminated almost immediately with obturator prostheses which also separate the oral and nasal cavities and maintain masticatory function, improve speech, deglutition, aesthetics and entirely the facial disfigurement of patients. Adequate treatment should be planned for different classes of maxillary defects. Materials and Methods: In this clinical report, we will present our approach to treatment of maxillary defects in two patients. Results: Obturator prosthesis improves speech, deglutition, aesthetics and function for the patient. Conclusions: In many cases, residual teeth and healthy tissues should be used for supporting the prosthesis. The quality of obturator for patient’s life can be increased after the rehabilitation applied by an interaction between surgeon and prosthodontist.

Poster Presentation No. 115 Oral rehabilitation of a patient with maxillo-mandibular defects: Multidisciplinary approach

Mescutsan Cilli, Ediz Kale, Osman Fatih Arpag, Aslıhan Koroglu Mustafa Kemal University, Faculty of Dentistry, Hatay, Turkey

Purpose: To present a multidisciplinary oral rehabilitation of a middle-aged patient who underwent series of oral surgery operations in order to have fixed trauma due to a traffic accident. Materials and Methods: Case Report: A 39-year-old female with depression and lowered self- esteem was referred to our clinic complaining of bad dental appearance. The patient had been involved in a car accident at age of 6 and she had undergone many maxillo-mandibular surgeries before. Oral and radiologic examinations revealed unilateral mandibular edentulism, fixed-dental- prostheses with poor occlusal harmony and mandibular removable-partial-prosthesis made of flex- ible resin material with altered fit and retention. The mandible had multi-segmental fracture and was fixed using bone screws and ligature wire. The trauma had compromised the growth pattern of the maxilla, whereas the mandibular bone has been reshaped with repeated plastic surgery. The patient was informed of the possible treatment options and any large oral surgery was ruled out because she had got tired of being operated. Less invasive periodontal surgery was scheduled after which prosthetic treatment get in progress. Gingival levelling was performed in the anterior maxilla by means of osteoplasty and gingivectomy. Maxillary full arch was restored with conventional porcelain-fused-to-metal fixed-dental-prostheses and the mandible was restored with precision attachment retained conventional removable-partial-prosthesis. The altered occlusion was fixed and chewing function restored. Results: At the end of the treatment acceptable aesthetics could be achieved and the patient was pleased with the result. Conclusions: Traumatic defects are often a challenge that can better be overcome with appropriate treatment by a multidisciplinary team of specialists.

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Poster Presentation No. 116 Multidisciplinary complete oral rehabilitation in an acquired maxillary defect case

Ali Mutlu, Ediz Kale, İbrahim Damlar, Soydan Kilic Mustafa Kemal University, Faculty of Dentistry, Hatay, Turkey

Purpose: To present an oral rehabilitation with a multidisciplinary approach for a difficult case of a young patient with acquired maxillary defect due to accidental trauma. Materials and Methods: Case Report: A 23-year-old male with an old history of traffic accident came to our clinic mainly with a complained of caries and difficulty in chewing. The trauma had compromised the growth pattern of the maxilla causing for deviation and cross-bite at the right posterior maxillary section and severe right-shift of the midline in the anterior. Some of the teeth had been lost, others had undergone tipping. The oral examination revealed poor oral hygiene and prevalent dental caries. The patient was informed of his condition along with the possible treatment options and after achieving acceptable oral hygiene invasive interventions were scheduled. First, oral surgeons performed unilateral rapid maxillary expansion in order to fix the posterior cross-bite. After 3 months of healing process, prosthetic treatment started so that to readjust the occlusion. Full-mouth conventional fixed-dental-prostheses were indicated. A new midline was set between the left side maxillary incisors and the upper teeth were prepared accordingly. After another 2 months of treatment porcelain-fused-to-metal fixed-dental-prostheses for all teeth were completed and delivered. Results: After more than 6 months of treatment acceptable aesthetic and functional outcomes were achieved and the patient was pleased with his new appearance. Conclusions: Traumatic defects often become complicated cases for treatment. A multidisciplinary team of dental specialists who work together can provide for better treatment outcomes and favour the long-term prognosis of the outcome.

Poster Presentation No. 117 Efficacy of a mandibular advancement splint in a dentate, severe obstructive sleep apnoea patient: A case report

Bulent Piskin, Bahadır Ezmenk Gulhane Military Medical Academy, Department of Prosthodontics, Turkey

Purpose: The aim of the present case report is to determine the efficacy of a mandibular advancement splint therapy in a dentate, severe obstructive sleep apnoea patient. Materials and Methods: A mandibular advancement device was fabricated with 12 mm vertical opening amount. 75% of maximal mandibular protrusion was applied to reposition of mandible. Splint was made with auto-polymerizing clear acrylic resin material. Results: Apnoea/Hypopnoea Index of the patient was decreased from 60 to 12 after splint therapy. Conclusions: Splint therapy could be efficient also in severe obstructive sleep apnoea patient.

Poster Presentation No. 118 Altering the patient’s aesthetic profile with all-ceramic restorations

Afroditi Yfanti, Stella Babi, Eustathia Andrikopoulou, Phophi Kamposiora National Kapodistrian University of Athens, Greece

Purpose: Restoration of the aesthetic area is a challenging procedure in everyday dentistry. Pa- tients often present with aesthetic demands that involve not only their teeth but also the facial

117 39th Annual Conference of the European Prosthodontic Association structures. Materials and Methods: Initially a thorough record of the patient’s expectations should be done followed by a conversation on which of them can be fulfilled. Waxing of the proposed treatment should include all the necessary changes of the teeth that will lead to the alternation of the facial structures. The outcome should be presented to the patient via a mock-up, in order to visualize and get acceptation of the result. Results: In this Poster Presentation the reconstruction of a patient using ceramic restorations to achieve minimal alternation of facial characteristics will be presented. Conclusions: The clinician should be very careful when creating a treatment plan for a reconstruction that may even slightly alter any of the facial characteristics of the patient.

Poster Presentation No. 119 Post extraction, prosthetic-driven, guided implant insertion and immediate loading

Varol Curt-Nazar, Ovidiu Dumitru Bucharest, Romania

Purpose: The aim of the case presentation is to explain a simple and predictable method how to immediately restore a hopeless tooth. This kind of case can be done by every general practitioner. Materials and Methods: A case report – with the help of a surgical guide done in-office, the practitioner can plan and place the implant in the ideal prosthetic position. Results and Conclusions: Combining CBCT with CAD/CAM technology the practitioner can control all the treatment stages, from planning and delivering a precise and predictable surgical, perio and prosthodontic rehabilitation of a lost tooth.

Poster Presentation No. 120 Prosthetic management for cleft palate patient: A case report

Kubra Degirmenci, Ayse Kocak-Buyukdere Kocaeli University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Cleft lip and/or palate is a congenital oral-facial situation associated with dental abnormalities. These defects cause functional, phonetic and aesthetic problems. Also, quality of patient´s life is influenced negatively. Treatment concepts of cleft lip and/or palate begin with birth for patients and continue to adulthood. Generally, the treatment requires multidisciplinary approach. This team contain mainly plastic surgeons, orthodontists, and prosthodontists. This case is about a prosthetic management of cleft palate patient with fixed dental prosthesis after orthodontic treatment. Materials and Methods: A 19-year-old female had mobile anterior segment of maxilla because of cleft palate after orthodontic treatment presented to Kocaeli University Department of Prosthodon- tics. Also she had functional problems because of missing teeth. After radiographical and clinical examination and teeth preparation a metal ceramic fixed dental prosthesis was planned for teeth 11, 14, 15, 16, 21, 24, 25 and 26 to fix anterior maxilla segment. Results: After 4 months, restoration was successful in fixing the anterior segment of maxilla and patient was satisfied with the prosthesis. Conclusions: Porcelain-fused to metal restoration is a good solution to immobilize anterior segment of maxilla. In addition, prosthetic rehabilitation promotes quality of patient’s life by improving patient’s self-esteem.

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Poster Presentation No. 121 Full mouth rehabilitation of a patient with Type 4 Amelogenesis imperfect

Ahmet Çalışkan, Zortuk Mustafa, Aydınbelge Mustafa, Çalışkan Seçil Erciyes University, Faculty of Dentistry, Department of Prosthodontics, Kayseri, Turkey

Purpose: Amelogenesis imperfecta (AI) is a heterogeneous inherited disorder that is characterized by abnormal formation of the enamel or external layer of the crown. The teeth have high risk for dental caries and are hypersensitive in addition to rapid attrition and excessive calculus deposition. Purpose of this study is to present treatment procedure of a 13-year-old boy with Type IV Amolo- genesis imperfecta which included hypomature and hypoplastic teeth structure and taurodontism. Thus the patient had reduced vertical occlusal dimension. Materials and Methods: All erupted teeth had needed to have root canal treatment because of severely damaged enamel and dentin structure and periapical infections. Large pulp chambers of the teeth were filled with Mineral Trioxide Aggregate (MTA). Afterwards fibre posts and fibre pinposts were used to support weak root dentin and to provide resistance and retention of core and metal- ceramic restoration. Results: Treatment procedure of present case has some limitations and it needs a multidisciplinary approach. Endodontic treatment was not possible with standard procedure of root canal treatment because of large pulp chambers and open apices. MTA was used for this purpose. To retain root support, fibre posts and laterally condensing small diameter pinposts were combined. Therefore weak root dentin was supported with elastically similar materials. The vertical dimension of occlusion was increased using metal-ceramic restoration and aesthetics and function were achieved. Conclusions: In this clinical report after endodontic treatment of infected teeth following fibre posts and fixed restoration showed successful full mouth rehabilitation for a patient with Amelogenesis imperfecta.

Poster Presentation No. 122 Ceramic laminate restoration of maxillary lateral incisors with surface modification

Esma Kuris Bastan, İlker Bastan, Gozlem Ceylan, İmran Kocak Bezmialem University, Department of Orthodontics, Turkey

Purpose: Crowding of anterior teeth in both upper and lower jaw mostly compromises the aesthetics and smile line of the patients. Materials and Methods: In this case report, 17-year-old female patient was referred to our clinic with complains for crowding of upper incisors. Beside the crowded maxillary crowded incisors, Bolton discrepancy of anterior teeth was indicated. Due to the treatment protocol, ceramic laminate veneer restoration without any tooth preparation assisted with Er:YAG (2940 nm) for surface modification and surface etching procedure was performed following orthodontic treatment to achieve aesthetic teeth positioning. The first step, orthodontic treatment protocol, was planned as a diastema between the maxillary central and lateral incisors during the setting aright the crowding of the teeth. The aim of the diastema was to enlarge the lateral incisors with laminate restoration to handle Bolton Discrepancy. Er:YAG (2940 nm) laser with H02 non-contact hand-piece was used to achieve etched surface of lateral incisors to increase attachment surface area of the teeth. Results: With this treatment protocol, maximum conservative and aesthetic result was established. Conclusions: Depending on the conservative treatment approach, minimal invasive and avoiding the hard tissue abrasion for needed the restoration, is the golden standard in dentistry.

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Poster Presentation No. 123 An alternative method in case of fractured abutment screw: A 4-years follow-up

Onjen Tak, Gamze Iyidogan Kocaeli University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: One of the causes of implant failures is the fracture of abutment screw which continues to be a serious problem in restorative practice and great challenge to remove the fractured screw conservatively as the fragment remaining inside the implant may prevent the implant from function- ing efficiently as an anchor. A simple and cost-effective method used for the successful utilization of the existing implant, abutment and prosthesis is described in this clinical report. Materials and Methods: A 61-year-old female patient who had two bone-level dental implants (Straumann) in maxillary anterior region was referred to our clinic for prosthetic treatment. After impression and fabrication of zirconia-based all-ceramic bridge, the screw of the original zirconia- based abutment was tightened to 35 N/cm2 with a torque wrench. While tightening the screw, it was fractured and could not be removed successfully by using rotary instruments without damaging the internal threads of the screw hole. Therefore an alternative method using the existing implant was planned and the abutment was cemented into the implant using self-adhesive resin cement (Panavia SA cement, Kuraray). The restoration was cemented with zinc polycarboxylate cement (Adhesor Carbofine, Spofa Dental) after verification of aesthetics and occlusion. Results: After a 4-year follow-up, continued stabilization of the abutment, implant and prosthesis was observed. During the follow-ups, no aesthetic, biological, functional and biomechanical complications were detected. Conclusions: The cementation of the abutment into the implant can be a good solution for the successful utilization of the existing implant as an anchor in case of fractured abutment screw.

Poster Presentation No. 124 Restoring of oro-nasal fistula using Andrew’s bridge: A case report

Kavut Idris, Şafak Külünk, Murat Yenisey, Numan Tatar Ondokuz Mayis University, Deparment of Prosthetic Dentistry, Turkey

Purpose: The Cleft Lip and Palate (CLP) is variation of a type of clefting congenital anomaly caused by abnormal facial development during pregnancy. The aetiology of CLP is unknown. The CLP patient is mainly characterized by the presence of an oronasal communication, malformation or congenital agenesis of the teeth close to the cleft and deficient sagittal and transverse growth of the maxilla. CLP needs complex treatment strategies scheduled in many years of duration. These patients require various treatments involving a multidisciplinary team, which may include a maxillofacial surgeon, an orthodontist, prosthodontist, speech therapist and all those professionals who can help provide functional and aesthetic improvement. CLP patients might be reconstructed with conventional prostheses or (dental-zygomatic) implant retained prostheses. Materials and Methods: In this case report, we restored 21-year-old cleft lip and palate patient’s masticatory function and improved speech, and aesthetics by using fixed-removable prostheses. Results: The technique has presented an Andrews bridge which was a fixed removable type of prosthesis. The obturator was light weight which was attached to the removable part of the An- drew’s bridge. Conclusions: Fabrication of the fixed-removable prosthesis which is obturator attached to Andrews bridge is a time consuming, labour intensive, artistic job. Surgical reconstruction was not possible in this case and it needed prosthetic rehabilitation. This promotes physical and psychological healing for the patient and improves the aesthetics.

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Poster Presentation No. 125 Solving dilemmas in rehabilitation of patients with implants

Slavoljub Tomic, Mihael Stanojevic University of East Sarajevo, Bosnia and Herzegowina

Purpose: Dental implants are used routinely in the contemporary dentistry. However, dilemmas still exist in prosthetic rehabilitation of so-called borderline cases. Such a dilemma can arise in the presence of big alveolar ridge depression – whether to rehabilitate an implant patient with fixed or removable denture resting on implants. The aim of this presentation is to demonstrate a possibility of relatively simple solution of such a case with fixed denture on implants. Materials and Methods: A case of female patient, aged 60, who lost her teeth in both lateral areas in the mandible, with the accompanying ridge atrophy, is presented. After a thorough case history, analysis of study models and x-rays, we decided to insert 2 dental implants in both lateral mandibular areas. After a period of osseointegration, a fixed denture was placed on the implants, with certain modifications compared to classical dental bridges. Results: As our patient didn’t have complaints on the aesthetics and function after temporary cementation and certain adjustments of the fixed dentures, we definitively cemented the fixed dentures operation with satisfactory functional and aesthetic results. Conclusions: Some questionable and borderline cases can be solved with fixed dental restorations on implants, after adequate planning and certain modifications.

Poster Presentation No. 126 Direct fibre-reinforced fixed dental prosthesis: Preliminary clinical findings of a case -con trolled clinical trial

Guliz Aktas, Didem Endam, Mustafa Baris Guncu, Mutlu Ozcan Hacettepe University, Faculty of Dentistry, Department of Fixed and Removable Prosthodontics, University of Hacettepe, Ankara, Turkey University of Zürich, Dental Materials Unit, Centre for Dental and Oral Medicine, Switzerland

Purpose: This case controlled clinical trial evaluated the clinical performance of direct, surface- retained fibre-reinforced composite (FRC) fixed dental prosthesis (FDP). Materials and Methods: Between June-2014 and April-2015, 5 patients (3 females, 2 males, 16–61 years old, mean age: 47) received a total number of 5 direct FRC FDP at the Hacettepe University, Ankara, Turkey. All restorations were made directly using E-glass woven fibres (Interlig, Angelus) in combination with resin composite (Filtek Ultimate, 3M ESPE). FRC FDPs were made either in the anterior segment of the maxilla (n = 2) or in the mandible (n = 3). No cavity preparations were made on the abutment teeth. One operator made all FRC FDPs. Initially enamel surfaces were cleaned with pumice and aprismatic enamel was removed with minimal preparation. After etching with 38%

H3PO4 for 30 seconds and rinsing for 30 seconds, adhesive resin (Tetric N Bond, Ivoclar Vivadent) and flowable composite (Clearfil Majesty Flow, Kuraray) were applied to the lingual surfaces of teeth accordingly. After baseline recordings, patients were followed every 3 months according to previously defined criteria. Patients were also instructed to call upon experience of a failure. Two calibrated operators performed additional qualitative analysis using modified USPHS criteria. Results: Mean observation period was 6 months with a maximum of 9 months. Altogether, one cohesive failure in the form of fracture was observed in the mandible after 3 months due to trauma where the pontic was tooth 41. This FRC FDP was renewed using the same protocol. According to USPHS criteria, no delamination of the veneering composite or debonding of the restoration from the enamel surface was experienced. Secondary caries and endodontic complications did not occur in any of the teeth. Conclusions: Preliminary clinical findings of 5 case series with the direct FRC FDPs using E-glass fibre in combination with a nano-filled composite resin showed only one failure. 121 39th Annual Conference of the European Prosthodontic Association

Poster Presentation No. 127 Prosthetic rehabilitation of a mandibular resection patient status post XRT

Phophi Kamposiora, Ioannis Papathanasiou, George Papavasiliou, Ioli Artopoulou National and Kapodistrian University of Athens, Dental School, Greece

Purpose: The purpose of this case report is to present a multidisciplinary treatment approach in the rehabilitation of a mandibular resection patient who received postoperative radiation treatment and to discuss the treatment limitations in irradiated patients. Materials and Methods: A 55-year-old woman presented in the graduate Prosthodontics clinic with a fractured mandibular removable partial denture and a history of mandibular resection followed by post-op radiation therapy. Intraoral examination revealed radiation induced carries and xerostomia. Considering the radiation dosage and the high risk of osteoradionecrosis, a treatment plan excluding implant placement and extractions was proposed. Teeth with poor prognosis were endodontically treated and crown amputated. Gingivectomy with laser was performed for conservative crown lengthening. Fixed partial dentures were fabricated with sanitary pontics over the remaining roots. A Co-Cr removable partial denture was constructed over the remaining mandibular teeth. A frequent follow up plan was scheduled. Results: After 12 months of function the patient was fully satisfied with functionally and aesthetics of the restoration. Conclusions: Irradiated patients subjected to tumour ablative surgery demand thorough clinical evaluation and individualized treatment planning considering their compromised health status and the possible treatment related complications. Clinicians need to be aware of the high risk of osteoradionecrosis as well as the lack of reliable clinical evidence for or against the clinical effectiveness of dental implant placement and hyperbaric oxygen therapy.

Poster Presentation No. 128 CAD/CAM inlays and onlays on posterior teeth

Gokce Dogar, Ayse Kocak-Buyukdere Kocaeli University, Faculty of Dentistry, Deparment of Prosthodontics, Turkey

Purpose: CAD/CAM restorations have many advantages for dentists and also for the patients. The aim of these case series is to evaluate aesthetic and functional clinical performance of CAD/CAM inlay and onlay restorations on posterior teeth by two different impression techniques. Materials and Methods: Six patients who did not have enough function, were referred to Kocaeli University, Faculty of Dentistry, Department of Prosthodontics. The cases were separated into two groups. Intraoral optical scanning was applied for half of the cases and plaster casts were achieved for optical scanning for the rest of the cases. The impressions were made with polyether. The restorations were fabricated using CEREC 3D (Sirona Dental Systems) and Panavia™ resin cement was used for cementation. The restorations were evaluated in regard to modified USPHS criteria. Results: After six months follow-up, good aesthetic and functional results were achieved, neither biological nor biomechanical complications nor restoration fractures were observed. Conclusions: CAD/CAM restorations offer aesthetic, functional, biocompatible, and long-term successful alternatives to traditional materials and techniques, especially CAD/CAM inlays and onlays offer a conservative preparation that preserves as much healthy tooth as possible, they preserve the maximum amount of healthy tooth structure, helping to ensure functional longevity.

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Poster Presentation No. 129 Survival of surface-retained indirect fibre-reinforced fixed dental prosthesis up to 43 months

Mutlu Ozcan1, Guliz Aktas2, Defne Burduroglu2, Mustafa Baris2, Guncu Filiz Keyf2 1University of Zürich, Dental Materials Unit, Centre for Dental and Oral Medicine, Switzerland 2University of Hacettepe, Department of Fixed and Removable Prosthodontics, Ankara, Turkey

Purpose: This retrospective clinical study evaluated the performance of indirect, anterior, surface- retained, fibre-reinforced-composite restorations (ISFRCR). Materials and Methods: Between September-2011 and September-2012, 17 patients (13 females, 4 males, 29–65 years old, mean age: 40.5) received 17 indirect FRC FDP at the Hacettepe Univer- sity, Turkey. All restorations were made indirectly on a plaster model using unidirectional E-glass fibres (Interlig, Angelus) in combination with a resin composite (Gradia, GC) and cemented adhesively with resin cement (Choice 2, Bisco). ISFRCRs were made in the anterior segment of the maxilla (n = 11) and the mandible (n = 6). No cavity preparations were made on the abutment teeth. The restorations were made at the dental laboratory by one dental technician. Before cementation, enamel surfaces were cleaned with pumice and etched with 38% H3PO4 for 30 seconds, rinsed for 30 seconds. Then adhesive resin was applied accordingly. After baseline recordings, patients were followed every 3 months up to 43 months according to previously defined criteria. The evaluation protocol involved technical (chipping, debonding or fracture of tooth/restoration) and biological failures (caries). Patients were also instructed to call upon experience of a failure. Survival rates, including repairable defects of FDPs, and success rates were determined (Kaplan Meier). Results: Mean observation period was 34.6 months. Altogether, 5 failures were observed (survival rate: 70.5%). Three debondings and two delaminations of veneering composite (chipping) were observed. All defective restorations were repaired or recemented, except one, which was remade. Conclusions: The 3-unit anterior surface retained indirect FRC FDPs with the E-glass fibre, veneering resin and cement could be advised as a semi-permanent treatment modality.

Poster Presentation No. 130 Abutment fracture in a single implant restoration: A clinical report

Alaleh Shojae Razavi, Atri Faezeh, Naghibi Sistani, Mohammad Mehdi Babol University of Medical Sciences, School of Dentistry, Prosthodontics Department, Iran

Purpose: This article describes a rare failure in implant dentistry. An abutment fracture in an implant-retained single posterior restoration and the step by step procedures of patient rehabilitation will be discussed. Moreover the probable aetiologies of this phenomenon will be evaluated. Materials and Methods: After 6 month’s function of a cement- retained restoration in first premolar region, the patient referred to her prosthodontist complaining of the fracture of her crown. Intraoral examination revealed the fracture of abutment body. Fortunately the abutment screw remained completely within the remnant of abutment and fixture therefore it was retrievable. Results: The fracture part of the implant abutment was removed, the fixture level impression was made and the process of remaking the restoration was done cautiously. Conclusions: Although some of implant complications are more prevalent, prosthodontists have to be well-organized to solve all kind of problems from screw fracture to implant body fracture. In order to avoid exposing to such situations, an appropriate diagnosis and treatment planning is mandatory.

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Poster Presentation No. 131 Perio-prosthesis approach: The use of conventional prosthodontics instead of implantology

Ismaili Zouheir, Hicham Soualhi, Layla Assila Faculty of Dental Medicine, Rabat, Morroco

Purpose: Through clinical cases, involving both function and aesthetics, we will highlight the contribution of conventional fixed prosthesis, periodontally conservative, in the treatment of anterior teeth with periodontal lesions. The management of this type of clinical case represents a therapeutic challenge. Indeed, certain situations put us in a dilemma, should we opt for a radical approach (by implantation extraction) or more conservative (preservation and restoration). Materials and Methods: The therapeutic decision requires a wealth of information to be collected (aesthetic information, functional and anatomical) and a multidisciplinary approach to choose the right treatment plan. Results: The use of conventional fixed prosthesis in the treatment of teeth with periodontal disease can help meet the needs and requirements throughout prosthetic restoration including in the par- ticular case of periodontal diseases. Conclusions: Fixed prosthesis is at the crossroads of other dental disciplines. In a case of multidisciplinary rehabilitation, prosthetics represents the last but not the least part of the work, particularly in cases of periodontal disease. Choosing a conservative approach, despite the difficulties it may present, and rigor required from the practitioner, may allow an aesthetic restoration, which respects all functional and biological needs of the periodontal patient.

Poster Presentation No. 132 Prosthetic reconstruction of anterior alveolar cleft using removable partial denture

Ozlem Colgecem, Merveal Altuntas Izmir Katip Celebri University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Cleft palate is a type of congenital deformity caused by abnormal facial development during gestation. The alveolar cleft is present in 75% of the patients with cleft lip and palate. Patients with cleft palate have physical anomalies including decreased vertical dimensions of occlusion, decreased facial support, lack of functional occlusion, altered speech, poor aesthetics, and lack of a normal smile line. Prosthetic treatment does not only eliminate the physical and functional defi- ciencies but it also overcomes the possible psychological effects of these deformities. Materials and Methods: This case report describes the oral rehabilitation of a 20-year-old woman born with cleft palate using a removable partial denture. She had inadequately repaired anterior alveolar cleft with poor lip support due to the extent of tissue deficiency and had also multiple missing teeth including maxillary incisors, right canine, second premolar and left first molar. To restore the defect and support the lip, removable partial denture was preferred. Maxillary right first premolar was infraoccluded and rotated. Due to improper crown/root ratio for fixed restoration, it was left under the denture after eliminating undercuts. The treatment was completed following the clinical and laboratory processes. Results: After first year follow-up, she was satisfied with the aesthetic and functional outcomes of this treatment. Conclusions: The use of removable prosthesis rather than fixed ones improves the aesthetic appearance supporting upper lip in these patients. Removable denture does not only fill the defect, but also restores the anterior dentition and overcomes the malocclusion. Thus, satisfying aesthetic and functional outcomes can be achieved.

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Poster Presentation No. 133 Full-mouth rehabilitation of severely worn dentition with VDO increase: A case report

Meral Kurt, Bilge Turhan Bal Gazi University, Faculty of Dentistry, Department of Prosthodontics, Emek, Ankara, Turkey

Purpose: Restoration of the severely worn dentition is a challenging procedure in dentistry. Be- cause it is frequently accompanied with loss of occlusal vertical dimension (OVD) that impairs patient´s function comfort and aesthetics. Materials and Methods: In this report, full mouth rehabilitation with metal-ceramic restorations of a 56-year-old male patient with a severely worn dentition was described. Clinical and radiological examination revealed severe attrition, unsuitable restorations, several missing teeth and an uneven occlusal plane. A reduction of the lower facial height, wrinkles and drooping commissures around mouth were observed during extraoral examination. Parafunctional habits and unsuitable restorations were considered as reasons of severe wear in this patient. Patient’s interocclusal rest space that measured between nose tip and chin tip was 7–8 mm larger than the normal distance. Full mouth rehabilitation with increasing OVD and restoring mandibular edentulous posterior region with implants was planned. Root canal therapy of anterior mandibular worn teeth was performed. Crown lengthening procedure was performed with pin retained and post-core restorations. To evaluate the adaptation of patient to the increased OVD, patient used the fixed interim restoration for 2 months. Muscle pain and temporomandibular discomfort were not reported by the patient during 2-months trial period. Results: Thus definitive full mouth metal-ceramic restoration was completed. At the end of treatment the patient was satisfied with the aesthetics and masticatory function of his restorations. Conclusions: For successful treatment determining the amount of reduction of the OVD is crucial. Also the increase in OVD provides more interocclusal space for the restorative material to achieve aesthetically pleasing restorations.

Poster Presentation No. 134 Bonded bridges: Any updates?

Hicham Soualhi, Layla Assila, Amal El Yamani Rabat, Morroco

Purpose: Through this work, we aim to put the item on bonded bridges, which is a type of conservative restoration, and its importance in our therapeutic armamentarium, exposing the different aspects of its evolution through clinical cases. Materials and Methods: Bonded bridge is a therapeutic option that is part of conservative adhesive and minimally invasive restorations. Faced with certain situations where the implant-prosthesis is not indicated, the use of such a restoration is unavoidable. The management of clinical cases with tooth loss treated by adhesive bridges illustrates the recent developments in the preparations, the design of the armature and the aesthetic improvement. Results: Replacing a missing tooth while preserving adjacent teeth of the “mutilation” has long been a concern for practitioners. The use of bonded bridge restoration, allows, when the indication arises, to obtain satisfactory results along with the biological, clinical and aesthetic requirements. Conclusions: In an era where the implant-prosthesis seems to be a treatment of choice for single tooth missing, the bonded bridge, is an adhesive and conservative restoration that always finds its place in our therapeutic arsenal.

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Poster Presentation No. 135 TMJ analyses in a young patient with idiopathic scoliosis

Beáta Benke1, Maria Kühn1, Dóra Markovics1, Gyula Marada1, József Váncsodi2, Márta Radnai1 1University of Pécs, Medical Faculty, Dental School, Department of Prosthodontics, Hungary 2University of Pécs, Medical Faculty, Department of Orthopaedics, Hungary Purpose: From anatomic and functional aspects the stomatognathic system and the upper cervical spine are closely connected. Together with complex neuromuscular relationships, this gives rise to an important field of cooperation between dentists and orthopedics. The aim of this case report was to demonstrate the improvements of TMJ function after orthopedic surgery in a patient with idiopathic scoliosis. Materials and Methods: Case presentation: A 15-year-old female patient who had adolescent idiopathic scoliosis was surgically treated in 2014. Functional analyses of the temporomandibular joint were performed before the day of operation, 7 months and 10 months after the surgery. For detection the Zebris (Achen, Germany) ultrasound-based testing machine was used. Results: The analyses of the data showed that almost all range of motions (ROM) were getting better. The deviation to the right side was reduced from 8 mm to 2 mm during mouth opening. In mouth opening significant change was not observed. The patient had limited left lateral movement before the operation, 10 months after the operation there were free motions towards both sides. The originally asymmetrical protrusion became almost completely symmetrical. Conclusions: Relating the functions of the TMJ the surgery was successful, since the range and the path of the mandibular movements improved without any other treatment. These improved functions are indirect evidences for the connection of the function of the upper cervical spine and TMJ.

Poster Presentation No. 136 Aesthetic rehabilitation with lithium disilicate glass-ceramic: Three case reports

Sezgi Cinel, Cennet Elcin Sagirkaya, Ismail Onur Şahin Ordu University, Faculty of Dentistry, Turkey

Purpose: Conventional fixed partial dentures are the therapeutic modalities for aesthetic zone until today. Recently, lots of new ceramic materials improved and came into use for aesthetic restorations. These ceramics show high clinical success, higher fracture strength and excellent aesthetics. The aim of our case report was to restore maxillary anterior teeth with lithium disilicate glass- ceramic (IPS e.max Press), which has optimized translucency, durability and strength for anterior aesthetic restorations. Materials and Methods: Our study was performed on three patients. All patients were referred to our clinic due to aesthetic reasons, such as deviousness problem, poor aesthetic of maxillary anterior teeth due to incompatible composite restorations and diastema between anterior teeth. After clinical investigations, full ceramic crown restorations were decided to use for one of these patient because of location on the arc of his teeth and interocclusal relationship. For other patients, ceramic laminate restorations were considered to be more appropriate. In all three cases, after checking marginal fit, proximal contour, occlusion and aesthetic, the restorations were cemented. Results: The patients were very satisfied with the result and had no complaints at the following control after six months. In the clinical controls, there was no evidence of periodontal, prosthetic or aesthetic complications. Conclusions: For aesthetic problems, lithium disilicate glass-ceramic laminate or crown restorations are highly successful treatment options when intraoral conditions are suitable.

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Poster Presentation No. 137 Multidisciplinary approach to functional and aesthetic rehabilitation of amelogenesis imperfecta

Ahmet Serkan Küçükekenci, Ersan Celik, Funda Fundaoğlu Küçükekenci Ordu University, Faculty of Dentistry, Department of Prosthodontics, Turkey Purpose: Amelogenesis imperfecta (AI), is a hereditary disorder in which the quality and quantity of the enamel of teeth is affected. In these patients various treatment plans might be considered due to this disorder’s possible effects on aesthetics, function, occlusion, phonation and gingival health of teeth. In this case reports, two patients diagnosed as AI were represented. Materials and Methods: Case Presentation: A 20-year-old female patient (case1) and her 19-year- old sister (case 2) with features of a variant of AI were referred to our clinic. They had complaint of appearance and poor masticatory efficiency which were the result of the destruction of the anterior crowns and multiple missing teeth. There were congenitally missing teeth and attrition of the molars had resulted in decrease of the vertical dimension of occlusion. The adaptation of the temporomandibular joints and masticatory muscles was carefully with 2 mm thickness acrylic plaques during 3 months. When the patients tolerated their new vertical dimension, they were treated with full-mouth metal reinforced porcelain fixed bridges. Results: As a result of the treatment aesthetic, functional and psychosocial problems were achieved in both cases. Conclusions: Clinical and radiological examination was made 6 months and 1-year after treatments. 1-year follow-up period of the patients did not reveal any complication. The restoration of aesthetics and function in patients with AI may be achieved with a dedicated team approach.

Poster Presentation No. 138 Restoring a lateral incisor with BioHPP resin bonded retained bridge

Stella Babi, Efstathia Andrikopoulou, Panagiotis Zoidis National and Kapodistrian University of Athens, Dental School, Greece

Purpose: This clinical report presents the use of a modified poly-ether-ether-ketone (PEEK) as an alternative material for the fabrication of resin bonded fixed dental prosthesis (RBFDP) framework for the restoration of a missing lateral incisor in a 14-year-old boy with cleft lip and palate. Materials and Methods: This modified PEEK material known as BioHPP, is a biocompatible, non allergic, rigid material, with good mechanical properties, wear resistance, chemical stability, high polishing and low absorption properties which has been used for years in orthopedics and medical technology. BioHPP frameworks can be constructed either via CAD/CAM manufacturing or via the conventional lost wax technique. Results: This new material can be used for patients allergic to metals, maintaining the same high aesthetic result of ceramics, presenting light weightiness and a flexibility similar to bone as a dis- tinct advantage over metal or ceramic materials. Conclusions: BioHPP has been used for the fabrication of fixed dental prostheses (FDP) frameworks, for the construction of individual implant abutments, even for removable dental prostheses (RDP) frameworks with good results. Therefore the use of BioHPP could be considered as a viable alternative over the conventional metal or ceramic framework materials for the fabrication of a resin bonded fixed dental prosthesis.

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Poster Presentation No. 139 PEEK based removable partial denture framework: A clinical report

Ioannis Papathanasiou, Panagiotis Zoidis, Gregory Polyzois National and Kapodistrian University of Athens, Dental School, Greece

Purpose: BioHPP is a biocompatible, non allergic, PEEK polymer with flexibility compared to bone, high polishing and low absorption properties. The purpose of this clinical report is to present an alternative treatment approach using a BioHPP framework in combination with traditional denture base acrylic resins for the fabrication of a mandibular removable dental prosthesis (RDP). Materials and Methods: A 70-year-old female patient presented with a conventional Cr-Co mandibular distal extension RDP with a lingual bar and roach clasps engaging the lower left second premolar and the lower right first premolar. The patient complained for the metallic taste, the weight and the unpleasant display of the metal clasps of her existing Cr-Co RDP and demanded an alternative material for the construction of a new RDP. The treatment plan consisted of a modified PEEK material (BioHPP) distal extension RDP framework with regular acrylic denture teeth and conventional heat cure acrylic resin bases. As a major connector a lingual plate was used in order to better withstand the torsion forces from the distal extension RDP. C clasps engaging 0.5 mm undercuts were constructed. Results: The patient was fully satisfied with the retention and the minimized weight of the new RDP and the white colour of the framework. After 12 months of function, no loss of retention and no signs of change on the BioHPP framework were observed. Conclusions: BioHPP could be considered as an alternative RDP framework material. However, further long term clinical evidence is needed in order to consolidate the scientific data.

Poster Presentation No. 140 Oligodontia treatment process: A case report

Anil Seckin, Süleyman Boukaya Gazi University, Faculty of Dentistry, Ankara, Turkey

Purpose: Tooth agenesis is one of the most common congenital anomalies seen in humans. Al- though absence of one or more teeth is common but absence of multiple teeth is rare. Oligodontia is a rare developmental anomaly, involving agenesis of six or more permanent teeth, excluding the third molars. Materials and Methods: A 24-year-old woman had aesthetic complications related to alveolar atrophy depended on oligodontia. We performed inlay grafting for aesthetic alveolar bone recovery using iliac crest to provide adequate horizontal and vertical bone volume and screws for bone fixing to avoid later damage to host bone during surgical removal. Temporary mini dental implants and prothesis were applied during the healing period to placement conventional implant. 3 months later, osseointegrated implants and permanent prosthodontic treatment were carried out. Results: No implants were lost during the observation time. Conclusions: Prosthetic rehabilitation is an urgent need for this kind of patients so that they do not suffer from masticatory and aesthetic problems which can eventually lower the self esteem of individuals.

Poster Presentation No. 141 Reproduction of emergence profile using CAD/CAM: A case report

Yohei Sato, Ema Muraishi Tsurumi University, School of Dental Medicine, Japan 128 39th Annual Conference of the European Prosthodontic Association

Purpose: In the case of re-repairing a crown, finish lines may already be present under deep gingival margins. It is important that the emergence profile is determined appropriately. The fabrication of the final prosthesis that planned healing of the gingiva by the adjustment of provisional restorations has been recommended. However, the form could not be replicated precisely and easily. In this case, we attempted to reproduce an emergence profile using CAD/CAM. Materials and Methods: A 30-year-old woman complained of aesthetic problems in her maxillary central incisors. Examination revealed that the tooth colour of the anterior tooth prosthesis was in- harmonious. Due to the incompatibility of the crown margin, inflammation was found in the gingiva. The old crowns were replaced with provisional restorations. In addition, the inadequate metal cores were replaced by composite resin cores with glass fibre posts. After it was confirmed that the fully adjusted provisional restorations did not cause inflammation, the forms were digitized by scanner and applied to the final all-ceramic restorations. Results: Crowns milled using digital data presented with forms similar to those of provisional restorations. All-ceramic crowns were delivered without needing any adjustments and, in harmony with the gingiva, were good aesthetically. Because it was a metal-free repair, the shadow of the crowns’ circumference gingiva disappeared. After two years of follow-up, the improvements in the gingiva and aesthetics were maintained. Conclusions: CAD/CAM can easily be used to recreate an accurate emergence profile for provisional restorations to lasting crowns.

Poster Presentation No. 142 Multidisciplinary treatment of severe incisor resorption due to ectopic maxillary canie: A case report

Ahmet Yagci, Yasemin Nur Korkmaz, Filiz Yagci Erciyes University, Faculty of Dentistry, Turkey

Purpose: Ectopic maxillary canine incidence is between 0.9 and 2 percent in the population. Eric- son and Kurol stated that resorption of permanent maxillary incisors due to ectopic canine eruption is a rare complication. Ectopically erupting maxillary canines may lead to resorption most commonly at lateral incisors, central incisors and rarely in first premolars. When the resorption is severe, it may even lead to extraction of the affected tooth. This case report demonstrates the multidisciplinary treatment of a patient with severe maxillary central incisor root resorption due to ectopic maxillary canine. Materials and Methods: An 13 years and 4 months old female patient with an impacted maxillary canine applied to Erciyes University, Faculty of Dentistry, Department of Orthodontics for treatment. After radiographic and computerized tomography evaluations, left maxillary canine was found to be localized in the left central incisors position and severe root resorption extending up to crown of the central incisor was identified. Clinical examination showed mobility and devitalisation of the left central incisor. Central incisor was extracted before starting the orthodontic treatment and impacted canine was orthodontically erupted by using elastic chain in the incisor position. Elastic chains were renewed once a month. The canine was restored with an all-ceramic crown after the orthodontic treatment. Results: Overall orthodontic treatment duration was 16 months. Conclusions: Successful orthodontic and prosthodontic management of the case was achieved. The results were functionally and aesthetically satisfactory.

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Poster Presentation No. 143 Orthodontic and prosthodontic treatment in a patient with severe anterior open bite: A case report

Filiz Yagci1, Ahmet Yagci2 1Erciyes University, Faculty of Dentistry, Department of Prosthetic Dentistry, Kayseri, Turkey 2Erciyes University, Faculty of Dentistry, Department of Orthodontics, Kayseri, Turkey

Purpose: This report describes the treatment of a 13-year-old girl with a severe anterior open bite. An intraoral examination showed that the patient had a severe anterior open bite extending from the left maxillary canine to the right second premolar. The molar relationship was class III. Right maxillary central incisor had been extracted and there was a vertical alveolar defect at the extraction site. The other three incisors had been treated endodontically and restored with metal screw posts but the crowns were severely damaged. Also there was a periapical lesion at left maxillary lateral incisor’s root apex. Materials and Methods: Prosthodontic treatment was planned following orthodontic treatment for the patient. During first 10 months of the orthodontic treatment, a monoblock was applied to achieve vertical growth of anterior maxilla. Then fixed orthodontic treatment was applied. After 4 years of orthodontic treatment, extrusion of the anterior teeth with alveolar bone and acceptable occlusion were achieved. Radiographic evaluation revealed that the lesion which was related with left maxillary lateral tooth didn’t improve in spite of endodontic treatment. Then apical surgery was applied. Left central and lateral incisors revealed mild mobility. Then an 8-unit metal-ceramic fixed partial denture was made from left first premolar to the right first premolar to increase retention because of negative overjet between maxillary and mandibular anterior teeth. Results and Conclusions: Interdisciplinary treatment of the patient with severe open bite produced good results aesthetically and the stability of the treatment was favourable at the 6th month follow-up.

Poster Presentation No. 144 Observation of soft tissue and vertical dimension changes using 3dMD

Simel Ayyildiz, Faruk Emir, Cem Sahin Gulhane Military Medical Academy, Department of Prosthodontics, Turkey

Purpose: The aim of the present study was to analyze the accuracy and validity of 3dMD to predict the position of the soft tissues of a complete denture patient three dimensionally. Materials and Methods: A 62-year-old female patient was referred to the clinic for renewal of her 10-year used denture. The extraoral examination revealed that the vertical dimension was reduced. Totally 15 photos were taken by a 3D imaging device (3dMD Ltd., London, UK) that shots every picture in 1.5 msec. The patient was positioned in rest position, centric relation position both with old dentures and new dentures. Vertical dimension of rest position was 63 mm, centric relation position with old dentures was 51 mm and centric relation position with new dentures was 57 mm. Linear changes and discrepancies of soft tissues were evaluated by 3dMD software. And also 3D changes and deviations were calculated by using Geomagic Control. The topographic colour coded map of deviations was reported. Results: According to obtained data the changes before and after treatment were 2.68 mm for labiale superius, 2.92 mm for labiale inferius, 1.99 mm for subnasal, 2.89 mm for pogonion, 1.98 mm for pronasal and 2.96 mm for sulcus inferior. Points moved forward positions after treatment. The area of the upper and lower lips was also calculated. The results were 388.9569 mm2 and 442.6625 mm2 before treatment and 435.5113 mm2 and 529.8522 mm2 after treatment, respectively. The area of the lips was increased. Conclusions: 3D imaging produces clinically acceptable three-dimensional soft tissue predictions and alternative method in determining vertical dimensions in complete denture patients.

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Poster Presentation No. 145 Study on longevity of prosthodontic treatments of transitional edentulous spaces in young patients

Maria-Antonela Beldiman, Ioana Martu, Ionut Luchian, Nicoleta Ioanid, Elena Luca University of Medicine and Pharmacy Gr. T. Popa, Iasi, Romania

Purpose: Prosthetic and orthodontic treatment of partial edentulous spaces in adolescents and young patients became a necessity to resolve the malocclusion in order to balance subsequent the occlusal relations. Premature loss of anterior or posterior temporary teeth can have consequences on the development of permanent dentition, the support serving to maintain space for teeth eruption in the dental arches. The aim of this study was the assessment of different types of space maintainers or prosthodontics therapy solutions in terms of their longevity, applied as interceptive orthodontic treatment for edentulous space management. Materials and Methods: The study followed the evolution of appliances properly applied to 145 clinical cases that required these therapeutic options, and appreciated the success rate (64%), and the failure of these devices. Findings failure rate (28%) was reported to the main causes that could lead to remove the devices: loss of removable space maintainers (22%), fracturing both fixed and removable appliances, loosening orthodontic rings and of course, the absence of some subjects at periodic reassessment meetings (15%). Results and Conclusions: The results of this study (designed to assess the longevity of some orthodontic and prosthetic appliances) are consistent with the data cited in the literature, and reveal as an important conclusion, the necessity of applying prosthodontic treatments, immediate but transitory, specific for young patients.

Poster Presentation No. 146 Prosthetic restoration in a patient with bilateral condylectomy as a consequence of trauma

Tugce Erginsoy, Eda Ozdere Selcuk University, Turkey

Purpose: Condylectomy is an invasive surgical procedure which is performed by reason of trauma, condylar hyperplasia and pathological conditions such as neoplasia and arthritis. Prosthetic rehabilitation is a challenging process in patients who had condylectomy operation resulted in limited mouth opening. The aim of this case report is to present the anterior prosthetic rehabilitation of a patient who had bilateral condylectomy because of trauma. Materials and Methods: A 39-year-old female patient was referred to the Selcuk University Depart- ment of Prosthodontics for prosthetic rehabilitation. Clinical assessment of the patient showed restricted mouth opening, missing teeth in maxillary anterior region and maloclussion with open bite. She was complaining about her aesthetic appearance of anterior teeth on the upper jaw. The patient had a facial trauma in childhood therefore condylectomy operation was performed in early ages. Temporomandibular and panaromic x-rays were taken. Surgical procedures for the purpose of increasing mouth opening were recommended to patient; but this treatment option was refused. Maxillary anterior teeth were prepared. The oral opening was insufficient for regular metal impression trays; because of this, sectional impression was taken with polyvinyl siloxane impression material. Teeth were restored with zirconia based porcelain fixed prosthetics. Pink porcelain was used to compensate the alveolar bone loss. Results: More aesthetic results can be obtained by using pink porcelain and zirconium oxide crowns comparing to metal fused to porcelain restorations. Conclusions: This clinical report describes anterior prosthetic rehabilitation of a patient with restricted mouth opening after bilateral condylectomy.

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Poster Presentation No. 147 Removal of a deformed implant cover screw: A case report

Betül Yılmaz Evmek¹, İbrahim Duran¹, Mahmut Sümer², Berre Karöz², Çağrı Ural¹ ¹Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Samsun, Turkey ²Ondokuz Mayis University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Samsun, Turkey Purpose: Dental implants have become one of the most popular techniques for replacing missing teeth and implant therapy is an effective and reliable prosthodontic treatment option. Implant complications can be categorized through biological and mechanical factors. Biological complications include unsuccessful osseointegration or peri-implantitis. Mechanical complications include screw drive deformation, screw loosening, screw fracture, prosthesis fracture and problems with attachments. Materials and Methods: A 57-year-old partially edentulous male was presented to Ondokuz Mayis University Department of Prosthodontics with functional and aesthetic problem. Clinical and radiographic examinations were done and an implant planned in posterior region. Surgical procedure was planned and expected healing period was three months. Second stage surgery was performed but complication was encountered while unscrewing the cover screw of implant with a hex driver. The drive of the cover screw was deformed, probably because of excessive load while unscrewing. We couldn’t overcome the complication by using a new hex driver so we decided to create a slot on cover screw. The slot was made by grooving the cover screw with a diamond tapering fissure bur using different technique. Groove was prepared in the form of semilunar for prevent damage to the inner surface of the implant. The cover screw was retrieved easily using the modified elevator. Results and Conclusions: The technique described in this article involves the use of inexpensive instruments commonly found in dental offices and by using this modified technique, it is easy to prevent the damage of internal surface of the implants.

Poster Presentation No. 148 Oral rehabilitation in an ectodermal dysplasia patient: A case report

Fatmanur Dumrul, Ongun Celikkol, Berk Celikkol, Birgul Ozpinar Ege University, School of Dentistry, Department of Prosthodontics Bornova, Izmir, Turkey

Purpose: Hereditary hypohidrotic ectodermal dysplasia (HED) is typically inherited as an X-linked recessive trait, characterized by deformity of at least two or more of the ectodermal structures – hair, teeth, nails and sweat glands. Abnormalities in number, size, and shape of teeth, and reduced salivary secretion, present in isolated oligodontia as well as in hypohidrotic ED. This case report describes the prosthodontic rehabilitation of a 22 years old female patient with hypohidrotic ectodermal dysplasia. Materials and Methods: The patient presented with failure in eruption of her permanent teeth and difficulty in chewing. She also had aesthetic problems. An extra-oral examination revealed a reced- ing hairline, scanty eyebrows, a depressed nasal bridge and prominent supra orbital ridges. Lips were protuberant and dry. Skin was dry and parched. An intra-oral examination revealed a mixed dentition with persist primary teeth. The vertical dimension of the lower face was also reduced. On radiographic examination, through the roots of teeth, which were present, were found to be short and conical. After clinical and radiological examinations diagnostic casts were obtained. Increase of the vertical dimension was planned with fixed partial dentures. Results: Oral rehabilitation was accomplished with fixed partial dentures. Treatment had major impacts on self-esteem, masticatory function, speech and facial aesthetic. Conclusions: Dentists are often the first who diagnose these patients. Therefore, they should be aware of the clinical manifestations of this syndrome. In conclusion, the most important aspect which has to be considered in these patients is the psychological impact which is caused by aesthetics. 132 39th Annual Conference of the European Prosthodontic Association

Poster Presentation No. 149 Minimal invasive approach with palatal veneers in dental erosion case

Burcu Kanat Ertürk¹, Önjen Tak¹, M. Erhan Çömlekoğlu² ¹Kocaeli University, Faculty of Dentistry, Department of Prosthodontics, Turkey ²Ege University, Faculty of Dentistry, Department of Prosthodontics, Izmir, Turkey Purpose: Dental erosions caused by gastric acid may result in hypersensitivity and aesthetics problems due to the dissolution of hydroxyl-apatite crystals and dilatation in dentine tubules. In this clinical report, the rehabilitation of a patient suffering from the gastroesophageal reflux of three years with full ceramic crowns and palatal veneers prepared by CAD/CAM technique based on minimal invasive approach principle is described. Materials and Methods: In the intraoral examination of a thirty-year-old woman with hypersensitivity and aesthetics complaints, wear facets on the palatal surfaces of maxillary anterior teeth resulting from acid effects were observed. Crown restorations were planned for central teeth because of the incisal fractures, and palatal veneers were decided on the worn palatal surfaces of the laterals and canines without any margin preparation. Digital impression was obtained by an intraoral scanner (Bluecam, Sirona). The designed crown and veneer restorations (Inlab Cerec V4.2.5) were fabricated in the milling unit (Cerec MCXL, Sirona) from multilayered feldspathic ceramics (Cerecblocs PC, Sirona), and lithium disilicate reinforced glass ceramics (IPS e.maxCAD, IvoclarVivadent), respectively. After crystallization firing and glazing procedures, the restorations were cemented with resin cement (Panavia F2.0, Kuraray). The patient was followed-up to 6 months. Results: Full ceramic crown and palatal veneer restorations prepared with CAD/CAM in a reduced time period showed clinically higher acceptable fit and aesthetics outcome. The patient was highly satisfied with the functional and psychological aspects. Conclusions: According to the preliminary results, palatal veneers prepared with minimal invasive approach can be used as an alternative to the conventional prosthetic treatments in dental erosion cases.

Poster Presentation No. 150 Transforming a removable prosthesis to an implant supported fixed

Giannis Natsios, Georgia Kalantzopoulou, Paris Ravanis, Phophi Kamposiora, Stavros Pelekanos National and Kapodistrian University of Athens, School of Dentistry, Department of Prosthodontics, Greece

Purpose: The introduction of osseointegrated implants has solved many clinical problems when treating edentulous patients. Implants have made it possible to avoid removable restorations and all the problems that are involved with this kind of restorations. The purpose of this poster is to present an alternative method of constructing two provisional implant supported fixed partial dentures using the existing provisional removable restoration in the mandible. Materials and Methods: The treatment plan in the mandible included the placement of four implants and two fixed partial dentures bilaterally in the posterior area. A provisional partial removable denture was constructed in order to restore the posterior occlusion and the implants were placed. Due to the complexity of the treatment plan in the maxilla, the final restoration in the mandible had to be delayed. After the osseointegration period, the removable partial denture was modified chairside using four provisional implant abutments and two fixed partial dentures were constructed. Results: As a result the patient was satisfied with the solution of a fixed provisional restoration during the whole restorative period. Additionally, the provisional fixed partial dentures resulted in a more stable occlusion with no economical surcharge, contributing to the success of the treatment plan in the maxilla. Conclusions: The avoidance of the use of a removable partial denture – even during the transitional period – can lead to a more favourable situation concerning both the occlusal stability and the patient satisfaction. 133 39th Annual Conference of the European Prosthodontic Association

Poster Presentation No. 151 Prosthetic rehabilitation of generalized tooth wear part II aetiology: Erosion

Georgia Pozidi, Aggeliki Lambrinoudi, Stavros Pelekanos, Phophi Kamposiora National and Kapodistrian University of Athens, Greece

Purpose: Tooth wear is a major problem and a challenge in current clinical dentistry. Loss of enamel can be differentiated into three causal categories: mechanical loss (attrition and abrasion), chemical loss and abfraction. Some of these individual mechanisms may occur simultaneously leading to the multifactorial aetiology of the disease. The aim of these case series (part I and part II) is to demonstrate the diagnosis, treatment planning and prosthetic management of generalized tooth wear due to erosion. Materials and Methods: The present clinical case regards the rehabilitation of a patient presenting extensive tooth wear on the maxilla due to erosion. Examination of her medical history revealed that she suffered in the past from bulimia, but had recovered by the time of rehabilitation. Erosive lesions were observed on the palatal surfaces of the maxillary anterior teeth and the occlusal surfaces of the premolars. Treatment plan included the increase of the vertical dimension – due to limited prosthetic space – and the fabrication of lithium disilicate crowns in centric relation. Results: The patient was fully adjusted to the new vertical dimension. The final prostheses restored the aesthetics of the patient’s smile and fulfilled her expectations. Conclusions: The use of adhesive techniques for the rehabilitation of the worn dentition is an innovative perspective which offers the advantage of minimal tooth removal and excellent aesthetics. There are many case reports in the literature; however, clinical trials or systematic reviews should be performed in order to verify the validity of the current treatment option.

Poster Presentation No. 152 Prosthetic rehabilitation in a patient with osteopetrosis: A case report

Imran Kocak, Gozlem Ceylan, Goknıl Ergun Kunt Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthetic Dentistry, Kurupelit/Sam- sun, Turkey

Purpose: Osteopetrosis, which is one of the complications of osteosclerosis, may result in such serious oral complications as osteomyelitis and exposed necrotic bone. This clinical report describes the oral rehabilitation of a patient with maxillary prosthesis with magnetic attachment system. Materials and Methods: A 35-year-old female patient, who suffered from osteopetrosis, came to our clinic due to aesthetic problem of the maxillary complete denture. After clinical and radiographic examination, the patient’s demands were evaluated. In the clinical examination it was seen that the patient was still using the maxillary complete denture with the magnetic attachment system for fifteen years. The patient had no problems in terms of magnetic retention but she had complaints about aesthetic of her prosthesis. We decided to make a new prosthesis to the patient with the same magnetic attachment system. Mandibular complete denture couldn’t be constructed due to osteosklerosis and scar tissue in the mandibular area. Results: Patient was clinically controlled during the first week, first month and third month following denture insertion. Conclusons: In terms of retention characteristics compared to other attachment systems, magnetic systems may be found insufficient in retention. In spite the decrease in retention of magnetic attachments, the patient had used the prosthesis for a long time with no complaints.

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Poster Presentation No. 153 Prosthetic rehabilitation of cleft lip and palate patient: A case report

Murat Yenisey, Onur Etoz Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthetic Dentistry, Samsun, Tur- key

Purpose: Treatment of patients with cleft lip and palate is completed with fixed prostheses, removable, total, implants and aims to restore aesthetics, phonetics and function and should be guided by the basic principles of oral rehabilitation, such as physiology, stability, aesthetics, hygiene and the expectations of the patient. In this case, a tooth supported overlay partial denture was applied. Materials and Methods: Thirty-one years old male patient, who had failed fixed partial denture in anterior region was referred to our department. After clinical and radiographic examination the tooth supported overlay partial denture was planned because of large maxilla-mandibular discrepancy due to severe maxillary atresia, need for impaired lip support and recovering the anterior open bite. Tooth preparations were done for telescopic crowns. Telescopic superstructure was incorporated within denture. Results: Only minor complications (dental plaque, de-cementation of copings) had been seen at one month, three months, six months, a year and two years follow-ups by clinical and radiographical evaluating. Patient was generally happy because of re-established aesthetics, phonetics and function. Conclusions: Overlay prosthesis allows reconstructing severe vertical and horizontal tissue defi- ciencies, maintains tooth and bone, aesthetics and phonetics.

Poster Presentation No. 154 Prosthodontic rehabilitation of diastema with zirconia-based restorations

Ceyda Güleç, Işıl Sarıkaya Gaziosmanpaşa University, Faculty of Dentistry, Tokat, Turkey

Purpose: Zirconia supported fixed partial dentures (FPD) have widely increased the clinical indications of metal free prostheses, showing more favourable mechanical characteristics compared to the early ceramic materials. The demand for metal free material with increased translucency may mimic the natural dentition. The all-ceramic systems can only be used to replace anterior teeth with single crown restorations or maximum with three-units FPDs. On the other hand zirconia restorations can also be used on molars with high strength. Materials and Methods: Case report 1: Woman, 18, had a diastema between right maxillary incisor and lateral anterior teeth. She was complained about her appearance was not aesthetic. Two-unit FPDs were planned for her because of over mesiodistal space. Case 2: Woman, 38, had a diastema between anterior maxillary teeth additional with the spaces in canine region because of bilateral embedded canine. Eight-unit FPDs were planned for her at the thought creating more aesthetic appearance also like her demand. The CAD/CAM technique (Tizian Cut 5 Smart, Schütz, Germany) was used for handling of zirconia frameworks (Tizian Blank, Schütz, Germany) in all cases. Porce- lain was veneered (Noritake Co, Japan) to zirconia copings with conventional techniques. And the restorations were cemented to the prepared teeth with glass-ionomer cement. Results: At the 6-months follow-up, no major complications were observed in all restorations. Conclusions: In this presentation prosthodontic rehabilitation of diastema with zirconia-based FPDs was described.

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Poster Presentation No. 155 Prosthetic rehabilitation of generalized tooth wear part I aetiology: Bruxism

Angeliki Lamprinoudi, Georgia Pozidi, Stavros Pelekanos, Papavasiliou National and Kapodistrian University of Athens, Greece

Purpose: Prosthetic rehabilitation of cases with generalized tooth wear is considered a challenge in current clinical dentistry. Loss of enamel can be differentiated into three causal categories: mechanical loss (attrition and abrasion), erosion and abfraction. Some of these individual mechanisms may occur simultaneously leading to the multifactorial aetiology of the disease. Purpose of this case series (Part I and Part II) is to demonstrate the diagnosis, treatment planning and prosthetic management of severe tooth wear due to bruxism. Materials and Methods: The case report concerns a patient presenting excessive tooth wear without loss of vertical dimension but with limited prosthetic space. The aetiological factor was daytime and nocturnal bruxism. Diagnosis was set by clinical findings such as muscular orofacial pain; patient’s self-report about bruxism and clinical findings such as loss of enamel with exposure of dentin, shortening of teeth, loss of tooth anatomy and previous restoration fracture. Prevention of further tooth wear, treatment of orofacial pain and increase of vertical dimension were obtained via an occlusal stabilization splint. Diagnostic wax-up at central relation and the diagnostic mock-up permitted the evaluation of aesthetic and functional rehabilitation. The patient was maintained in provisional restorations for a period of 6–8 weeks. The prosthodontic treatment consisted of minimally invasive all-ceramic restorations. Results: The patient was fully adjusted to the new vertical dimension and was satisfied with the aesthetic result. Conclusions: The use of adhesive techniques for the rehabilitation of worn dentition is an innovative perspective which offers the advantage of minimal tooth removal and excellent aesthetics.

Poster Presentation No. 156 Bond strength of fibre-reinforced resin posts

Zsolt Rajnics, Gyula Marada, Moetaz El-Hag, Márta Radnai University of Pécs, Hungary

Purpose: The study was completed to evaluate the effect of silane on the push-out bond strength using glass-fibre reinforced posts. Further aim was to determine if there is a regional relation between the adhesive system and the push-out bond strength of the fibre post using different luting agents. Materials and Methods: Fifteen single rooted human teeth were endodontically treated and 2.0 mm diameter glass fibre-reinforced composite post (Rebilda, VOCO) were cemented. In the first group Rebilda DC (VOCO) without silane, in the second group the same luting material with silane, and in the third group Clearfil DC Core Automix (KurarayDental) without silane were used to lute the posts. After complete setting of the luting agents three 2mm-thick rods were obtained from the cervical (A), middle (B), and apical (C) regions of the roots. The specimens were then subjected to push-out testing in special equipment (Lloyd 1000 R Materials Testing Machine). Bond strength data were analyzed with ANOVA tests. Results: The Rebilda technology without silane had the highest push-out bond strength at the coronal region (164.71 N ± 72.12), while the Clearfil technology without silane had the lowest value at the apical region (94.86 N ± 34.14). Using silane had no significance on the push-out bond strength (P = 0.909), however the root canal dentin regions had a significant effect (P < 0.010). Conclusions: This study showed significant differences among different luting protocols. The bond strength was significantly higher in the coronal region due to the greater cemented surface area and the difference in dentin structure.

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Poster Presentation No. 157 Prosthodontic rehabilitation of mandibular trauma patients with precision attachments

Yadel Hazır, Işıl Sarıkaya, Yeliz Hayran Gaziosmanpaşa University, Faculty of Dentistry, Tokat, Turkey

Purpose: In this case reports, prosthodontic rehabilitation of mandible trauma patients with precision attachments based removable partial dentures (RPDs) were presented in two cases. Materials and Methods: Patients’ common complaints were aesthetic deficiency and chewing disability. Case I; age 56, man, has a devastated mandible with a traffic accident 27 years ago and he has not got any treatment to the present. He had five teeth (11, 12, 21, 22, 17) in the maxilla and six teeth (33, 34, 35, 41, 42, 43) in the mandible. Metal supported fixed partial dentures (FDP’s) and RPD with precision attachments (ball attachments) were planned for him. Case II; age 36, man, has a gunshot injury in the region of mandibular symphysis. Mandibular anterior teeth without right canine were extracted during the maxillofacial surgery because of the mandibular injury. Also, FPD’s and RPD with snap on attachments were planned for him. Veneer crowns were made on both sides of the gap and Dolder bar was used between crowns. Results: Thus, we increased vertical dimensions and provided the patients’ function and aesthetics again. Conclusions: There are various attachment types that can be employed and the choice of the attachment system is one the most difficult tasks for the clinician. The choice of systems should be orientated on the clinical situation and anatomical structures, oral hygiene, individual needs of the patients and economic factors.

Poster Presentation No. 158 Implant-retained prosthetic rehabilitation of an edentulous patient: A clinical report

Ongun Celikkol, Gizem Yaman, Ugur Tekin, Mehmet Ali Güngör Ege University, School of Dentistry, Department of Prosthodontics, Bornova, İzmir, Turkey

Purpose: Complete maxillary and mandibular dentures have been the traditional standard of care for edentulous patients. However, most of the patients report various problems. Implant supported overdentures offer many practical advantages over conventional complete dentures. They may be retained by a variety of attachments. Regardless of attachment type, these prostheses appear to have significant prosthodontic maintenance requirements, which can be time-consuming and expensive for the patient, clinician, and technician. This study presents a fabrication of the implant- retained overdenture that uses four freestanding maxillary and mandibular implants. Materials and Methods: A 65-year-old female patient reported for the prosthodontic rehabilitation of her implant placed edentulous jaws. She had 4 implants in maxilla (Bicon) and 3 implants (Zimmer) in mandible. Her medical history revealed that the maxillary implants were placed 5 years ago and mandibular implant 16 years ago. Locator type of cylindrical attachment system (Bicon) had been used in maxilla and O-ring attachment system in the mandible for her old dentures. After conventional preliminary impression making, light body additional silicone impression material was used for final secondary impressions. Vertical dimension and bilateral balanced occlusion in finished dentures were established. Results: First recall was attended after 24 hours. The regular follow-up was advised every six months. The patient was followed for six months without any complaints. Conclusions: Implant-retained overdenture remaking without changing the problem-free abutment types is a simple, cost effective solution in the rehabilitation of the edentulous jaws. Patient motiva- tion, education and post-treatment follow-up are critical for the successful treatment outcome with implant supported complete dentures.

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Poster Presentation No. 159 Centric relation recording techniques in patients with craniomandibular dysfunctions

Pantea Vitalie, Oleg Solomon, Daniela Chirita, Vadim Popovici, Cristina Rosca State University of Medicine and Pharmacy “Nicolae Testemitanu”, Republic of Moldova

Purpose: Applying leaf gauge and anterior jig techniques and stating their advantages for centric relation recording in patients with craniomandibular dysfunctions. Materials and Methods: 10 patients were examined with signs and symptoms of craniomandibular dysfunctions. Centric relation was determined using anterior jig and leaf gauge techniques. Both methods use a device – either an acrylic jig or a set of 0.1 mm thick leaves, which is placed between patients central lower and upper incisors. It separates the lateral teeth, releases the elevator muscles and creates a tripodization. The patient is asked to slide the mandible forward and backward and bite slightly. Primarily, in the leaf gauge technique lateral contacts are absent, so several leaves are removed until the first lateral contact appears. For the anterior jig technique, we obtained a uniform contact of the lower incisors with the jig surface. Both contacts were verified with articulat- ing paper, placed on the lateral teeth in the first method and between the jig and teeth surface for the second one. Results: We obtained the temporomandibular joint loading, lateral pterygomandibular muscle deprogramming and identification of the teeth contacts which indicate the centric relation recording. The electromyography revealed the reduction of pathologic muscle activity, as seen in the absence of pathological engrams. Conclusions: These techniques allow the neuromuscular system to seat the condyles in their individual centric relation by deprogramming muscles and allowing the condyles to seat in the most superior position ideal for prosthodontic treatment.

Poster Presentation No. 160 Multidisciplinary treatment in a patient with aggressive periodontitis: Case presentation

Metush Disha, Fatmir Dragidella, Gloria Staka, Zana Sllamniku-Dalipi, Kastriot Meqa, Saranda Disha, Teresa Disha, Donika Dragidella, Burim Gutiqi, Edon Behluli University of Prishtina, Dentistry School, Republic of Kosovo

Purpose: Periodontitis is a chronic, irreversible and destructive disease resulting in tooth loss. Its aggressive form produces defects in a very short time-frame that leads to premature tooth dysfunction and consecutively extraction is the only option. Materials and Methods: Patient FM, age 45, was referred for periodontal treatment with migration and mobility of majority of dentition, especially in mandibular region. After clinical and radiological evaluation, the treatment plan included periodontal surgery with multiple extractions of teeth 18, 17, 28, 38, 32, 41, 42, 47 and 48 during the course of surgery. Widman-modified flap surgery was undertaken for both jaws and after extraction the sutures were placed. Results: After periodontal surgery the condition of mandibular periodontal tissues was ready for fixed bridge, showing no signs of periodontitis. The bridge, consisting of 46 to 36, was placed after two months and periodic evaluation of periodontal tissues showed no recurrence of periodontal inflammation. The two-year follow-up showed maintenance of treatment results. Conclusions: In order to achieve better results for fixed prosthetic appliances, the multidisciplinary approach, including periodontal treatment, must be carefully planned, especially in the case of aggressive periodontitis.

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Poster Presentation No. 161 Prosthetic rehabilitation in a patient with combination of three precision attachments

Hayran Yeliz, Kaan Yerliyurt Gaziomanpasa University, Faculty of Dentistry, Department of Prosthodontics, Tokat, Turkey

Purpose: The present case report aimed to provide the patient’s aesthetic and functional expectations with using different precision attachment combination. Materials and Methods: 45-year-old male patient was referred to us to have a new prosthesis. In the clinical examination we observed long edentulous span on the maxillary arch and unilateral edentulous span on the mandibular arch. Due to economical limitations we couldn’t use implants and we decided to make removable partial dentures. He desired aesthetic replacement of the missing teeth and an increase in the chewing efficiency. So we decided to use attachment-retained removable partial denture. Eligible teeth were prepared first to provide abutment for the attachments. In the maxillary arch we preferred to use two different precision attachment combinations. We used extracoronal ball attachment on the left side and the dolder bar attachment to right side due to insufficient distance between the adjacent teeth. Because of unilateral free-ended partial edentulism, we preferred to use extracoronal Fm 1 hinge precision attachment in the mandibular arch. Results: The patient was satisfied with the retention and stability of the prosthesis. He was pleased with the functional and the aesthetic result of the treatment. Conclusions: Retention and stability of dentures can be increased with precision attachment retained removable partial denture. Precision attachments can be used to provide an aesthetic alternative to a conventional circumferential clasp in a removable partial denture.

Poster Presentation No. 162 Restoration of horizontally fractured anterior teeth: A case report

Elchin Abbasov, Murat Yenisey Ondokuz Mayis University, Faculty of Dentistry, Atakum, Samsun, Turkey

Purpose: The present case report aimed to describe the restoration of teeth by cast-post and metal supported porcelain. Materials and Methods: A patient with 5 anterior broken teeth in maxilla (12, 11, 21, 22, and 23) referred to our clinic for prosthetic treatment. The patient’s complaints were aesthetic deficiency and chewing disability. We decided to repair these teeth by cast post. Cavity and teeth canals were prepared for cast post. Then we took impression from these canals and cavities with an A (additional) silicone material. Cast posts were prepared in laboratory. We cemented the posts. Afterwards we took impressions of cast posts and prepared metal supported porcelains on them. Results: After a follow-up period of 3 months it was determined that all functional and aesthetic requirements were fully compensated without any complaint. Conclusions: The combination of cast post with metal supported porcelain on it is a conservative treatment alternative to prefabricated and standard post. These restorations are preferable option due to their low costs, tooth preservation, durability and compatibility.

Poster Presentation No. 163 Ridge atrophy of the mandible in relation to prosthetic treatment

Alwin Alan Sokolowski, Armin A. Sokolowski, Sandra H. Huber, Walther A. Wegscheider Medical University of Graz, Austria

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Purpose: The aim of this retrospective cohort study was to investigate the difference of the post- therapeutical alveolar ridge atrophy between implant-supported dentures and conventional dentures. Materials and Methods: In total of 479 patients met the inclusion criteria. To determine bone atrophy, two panoramic radiographs, taken at the time of prosthetic treatment and after a minimum time lapse of 3 years, were analysed and compared. Results: There was a statistically significant linear resorption over time in partial model casting dentures (n = 108, p = 0.006) and telescopic dentures (n = 61, p = 0.002). Mean bone loss in partial model casting dentures was 1.99 mm, in telescopic dentures 1.88 mm and in complete dentures 3.18 mm (n = 18). In single-tooth implants mean resorption was 0.28 mm (n = 130), in fixed partial dentures 0.15 mm (n = 48), in bar-retained implant supported dentures on 4 implants 0.13 mm (n = 91). On more than 4 implants 0.12 mm (n = 9). Restorations on 2 implants with Locator®- -attachments (4 mm, n = 4) and bar-retained implant supported dentures on 2 implants without extension (1.73 mm, n = 5) showed significantly higher atrophy than bar-retained implant supported dentures on 4 implants (p < 0.01). Conclusions: Our study demonstrated that the degree of bone atrophy in the posterior region of the mandible is highly dependent on the prosthetic treatment. Fixed partial dentures and permanent implant-supported restorations ensured long-term bone preservation. In edentulous mandibles, the bar-retained dentures supported on 4 or more implants showed the lowest grade of atrophy. There- fore restorations supported with implants should be preferred to removable conventional dentures in terms of preserving alveolar bone volume.

Poster Presentation No. 164 Rehabilitation of vertical dimension in patient with tooth wear: A case report

Arlinda Tmava-Dragusha, K. Shala, L. Dula, Z. Lila-Krasniqi, E. Dragusha, E. Ahmedi, T. Bicaj, T. Pustina University Dentistry Clinical Centre, Pristina, Republic of Kosovo

Purpose: The management of tooth wear has been a subject of increasing interest from both preventive and restorative points of view. Tooth wear (TW), also known as tooth surface loss (TSL) is multifactorial process involving destruction of enamel and dentine which can threaten tooth survival and oral health related quality of life of affected individuals. Materials and Methods: A 55-year-old male patient was referred to the Department of Prosthodon- tics at the University of Pristina, Kosovo, for treatment of his severely worn dentition (Figure 1). Clinical and radiographic examinations and diagnostic cast revealed severe attrition, especially on anterior teeth and uneven occlusal plane. The causes of the severe wear were parafunctional habits due to missing teeth in posterior region in maxilla and mandible. The treatment plan was to restore mandibular and maxillary edentulous posterior region with removable partial dentures (RPD), metal ceramic restoration in maxilla and crown lengthening procedure. As there was clinical evaluation of reduced vertical dimension of occlusion (VDO), full mouth rehabilitation with increasing VDO was planned. Results: In these case reports, a satisfactory clinical result was achieved by restoring the vertical dimension with an improvement in aesthetics and function (MI-Young Song et al 2010). Conclusions: In the treatment of severely worn dentition, the rehabilitation using restoration of anterior crown and RPD providing posterior support is affordable and common for many patients because of economics and tradition. However, the restored anterior teeth can be easily exposed to excessive occlusal loads if the patient does not wear RPD.

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Poster Presentation No. 165 Achieving anterior aesthetics in one-visit by using CAD/CAM technology

Çağrı Ural, Gülümser Örkün, İbrahim Duran Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: Technological developments on Computer Aided Design/Computer Aided Machining (CAD/CAM) systems and the demand of aesthetic aspect have lead to alternative treatment options. In this case, it was aimed to achieve anterior aesthetic with fabricating a laminate veneer and an implant supported all-ceramic crown on custom zirconia abutment by using CEREC 3 Omnicam system. Materials and Methods: Case Presentation: Twenty-three years old female patient, who has lost left maxillary central tooth due to trauma and crown malformation of right central tooth, applied to our clinic one year ago because of aesthetic concern. An implant supported single crown restoration and a laminate veneer were suggested to the patient as a treatment plan. Four months after the implant surgery, a screw retained provisional restoration was fabricated for soft tissue management and emergence profile. When the soft tissue management completed individual Ti-based zirconium oxide abutment was inserted, the restorations were fabricated and delivered to patient in one visit. Results: During the controls 15 days, one month, three months and six months respectively after the treatment the patient was evaluated clinically and no complications were observed. By this methodology, production stages of restorations are reduced and technical errors in production were minimized. Conclusions: The traditional methods have been described to be time-consuming, technique sensitive and unpredictable due to many variables and CAD/CAM may be a good alternative for both the dentists and laboratories. Ceramic abutment has the strength and precise fit of a titanium interface and also the aesthetic advantages of shaded custom-milled zirconia with no visible metal.

Poster Presentation No. 166 Periodontal-prosthetic treatment approach to manage gummy smile and skeletal class III patient: A case report

Tamer Celakil, Mutlu Keskin, Emrah Baca, Gulumser Evlioglu Istanbul University, Faculty of Dentistry, Department of Prosthodontics, Turkey

Purpose: A gummy smile poses prosthetic and periodontal challenges for dentists attempting to achieve ideal aesthetics. Gingival contouring procedure can create a mucogingival defect or biological width devastation. Materials and Methods: A 37-year-old female presented with a complaint of excessive gum visibility while smiling as well as in resting lip position and crowding. Clinical and radiographical assessment of the concerned area was carried out to rule out any major pathology of the region. A diagnostic wax-up and 1 mm durable copolyester outer layer guide were fabricated for marking gingival level. Gingivectomy was preferred over flapless surgery and mock-up was used like temporary prosthesis after gingivectomy surgery. Using self-cured temporary acrylic, an intra oral mock-up was created that exactly duplicated the wax-up in temporary veneers after tooth preparation procedure. Results: The patient was reviewed after a month, and 1 year follow-up the case has been completed. The gummy smile was significantly reduced and she also maintains good gingival health. The profile had improved with prosthetic treatment and she is satisfied with the prosthesis. Conclusions: It is important during treatment planning to evaluate the anatomical relationship that issued in the gummy smile and choose the appropriate periodontal and prosthetic treatment to eliminate this condition.

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Poster Presentation No. 167 Aesthetic restorations for posterior teeth: A CAD/CAM study

Hilal Eksi Istanbul Aydin University, Turkey

Purpose: The aim of this study is to provide the patient’s prosthetic rehabilitation with CAD/CAM techniques and without any try-in appointment, using Cerec Blocs PC whose have appropriate resistance and aesthetic properties at the posterior region. Materials and Methods: 35-year-old female patient with no systemic disease, admitted to the clinic of prosthodontics for the restoration of teeth 25, 26. According to the clinical and radiographic examinations; there was no pathology in the related teeth and surrounding tissues. And then it was decided to do the endocrown for tooth 26 and full crown for tooth 25. Amalgam restoration was removed and then prepared for endocrown. Both teeth were prepared with shoulder cervical finish line. The preparations were screened and designed with Sirona Cerec (it wasn’t used any retraction techniques) and then was sent to milling unit. After glazing (Ivoclar glazurpaste), it was cemented with adhesive cement (Panavia sa cement). Results: At the end of treatment, the patient’s expectations, relating to aesthetics and function, were fulfilled. Conclusions: The follow-up will be necessary for long-term success.

Poster Presentation No. 168 Porcelain lamina restoration – two cases of its use

Markéta Polednová Dental practice, Kolín, Czech Republic

Presentation was cancelled.

Poster Presentation No. 169 Custom abutment materials

Aydan Boztuna Istanbul University, Turkey

Purpose: In the dental implant applications, prosthodontic rehabilitation step is as vital to success as the surgical procedures. Implant prosthodontic restorations can be fabricated with different techniques. For some cases, using custom abutments may become imperative. The greatest reason for this necessity is the implant placement hindering prosthodontic rehabilitation functionally and esthetically. The prefabricated abutments provided by the implant companies are accepted as the gold standard because of their biocompatibility and advanced mechanical properties. Materials and Methods: A case report: The 31-year-old female patient came to our clinic, with com- plain about the discomfort of the metallic reflection from the upper side gingiva of the implant which is located on the 22nd dental region. We decided to apply the abutment which is prepared with a CAD/CAM system as a customize ceramic abutment. The measurement which’s sent to the lab is transferred to the computer and with CAD/CAM system, customize l zirconia abutment preparation is done. Results: Titanium superstructures’ grey color reflection through theperi-implant mucosa influences the esthetical view negatively. Implementation of CAD/CAM systems in the use of custom abutments production process is accelerated and the technician errors are eliminated both. In the fol-

142 39th Annual Conference of the European Prosthodontic Association lowing period, with more researches the materials become that more durable, having less producing time and lower cost are expected. Conclusions: With the increase of the number of variations in actual techonology and materials, clinicians get the oppurtunity to make more succesful restorations within long-term studies.

Poster Presentation No. 170 Iatrogenic fracture of a lithium disilicate crown during cementation

Matthias Karl, Nina Moore University of Erlangen-Nuremberg, Germany

Purpose: Lithium disilicate ceramic is frequently used for the fabrication of all-ceramic restorations and shows promising long-term results. For the successful use of all-ceramic systems, manufacturer specific guidelines with respect to processing, design and cementation have to be followed. Materials and Methods: Following chamfer preparation of a maxillary left second molar, a single crown was manufactured from lithium disilicate ceramic. This crown fractured during cementation using self-adhesive cement. Fractographic analysis of the fractured surfaces was subsequently performed using a scanning electron microscope. Results: At the fracture origin, the overall thickness of the crown was only 0.4 mm. A small radius of curvature potentially carried out manual adjustment as well as porosities in the glaze, all occurring in that area, may have promoted the fracture. Conclusions: Strictly observing material-specific preparation guidelines seem to be a prerequisite for successful all-ceramic restorations. Frequently advocated minimally-invasive restorations with reduced material thickness require adhesive cementation prior to loading.

Poster Presentation No. 171 A case report: Treatment of peg-shaped lateral incisors with porcelain laminate veneers

Merve Aytuğ, Hamit Serdar Çötert Ege University Faculty of Dentistry, Department of Prosthodontics, Izmir, Turkey

Purpose: Microdontia commonly affects maxillary lateral incisors called peg-shaped laterals. This situation creates an unpleasant smile. Porcelain laminate veneers (PLV) are being cited as the best restorative material due to its aesthetic specifications and resistance to wear and staining. The aim of this study is to present the aesthetic improvement of peg-shaped lateral incisors by using PLVs. Materials and Methods: A young adult patient had short, peg-shaped and retrusive lateral incisors. PVL was planned to develop mesiodistally and incisogingivally larger and protrusive lateral incisors. The case was focused on a clinical technique that involved the formation of a subgingival cervical chamfer and the removal of 0.5 mm enamel from buccal surface. In addition, overlapped incisal edges were created. Contact areas were not prepared. For the cementation, e.max express laminate veneers were etched with hydrofluoric acid and silanized. Teeth were etched also with 37% phosphoric acid and bonding agent was applied to the teeth. PVL was then cemented with adhesive resin cement (Variolink). Results: Peg-shaped laterals can be also treated by resin composite restorations or conventional crown restorations. This case was treated by PVL with a conservative preparation and a pleasant smile harmony was created for the young patient. The conservative preparation is anticipated that the long-term durability and aesthetics of PLV will be an advantage over composite resin restorations and crown restorations. Conclusions: PVL must be preferred as a restorative material to correct tooth morphology abnormalities due to its aesthetic specifications and resistance to wear and staining.

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Poster Presentation No. 172 Incidence of TMJ signs in complete denture wearers versus partial denture wearers

Dana Gabriela Bosinceanu, Dan Nicolae Bosinceanu, Norina Consuela Forna University of Medicine and Pharmacy Gr. T. Popa, Iasi, Romania

Purpose: The aim of this study was to find and quantify the incidence of clinical signs of TMJ disorders in complete and partial denture wearers. Materials and Methods: The patients were denture wearers who came in Faculty of Dentistry in Iasi for replacement of dentures. A questionnaire and a clinical examination were used to assess 200 patients Results: It was shown that there was a statistically significant difference between the two types of denture wearers regarding the presence of TMJ signs. Conclusions: The partially edentulous patients (wearing RPD) exhibited more TMJ signs compared with the CD-wearing patients.

Poster Presentation No. 173 Complications in complete denture wearers: A clinical study

Dan Bosinceanu, Doriana Agop-Forna, Dana Bosinceanu, Norina Consuela Forna University of Medicine and Pharmacy Gr. T. Popa, Iasi, Romania

Purpose: The aim of this clinical study was to assess the frequency and type of prosthetic complications in terms of several variables, in denture wearers patients that had been treated and came back for new dentures, in Faculty of Dentistry in Iasi, Romania. Materials and Methods: The patients were 104 patients with a mean age of 65.3 years wearing complete dentures. The complications and parameters related to the dentures such as the accuracy of vertical dimensions and centric relation, arrangement and possible malposition of the artificial teeth, and the border length of the denture bases. Results: The most common complication was loss of retention followed by ulceration. Conclusions: recalls seem to be important for complete dentures wearers, as many complications may develop and cause damage to the dentures as well as to the patients’ tissues.

Poster Presentation No. 174 Accuracy of different types of wrenches fabricated by different manufacturers

Halil İbrahim Kilinç, Haydar Albayrak, Funda Tursun, Hasan Önder Gümüş Erciyes University, Faculty of Dentistry, Department of Prosthodontic Dentistry, Kayseri, Turkey

Purpose: The aim of this study was to evaluate the accuracy of wrenches of different implant manufacturers in delivering target torque values. Materials and Methods: Five new and unused wrenches from each of 4 different implant manufacturers (Straumann, Implance, Dyna, Biohorizons) were selected to evaluate their accuracy of reaching their target torque values. Two types of the wrenches were friction style while the other two were spring style. To measure torque value of each wrench, a digital torque device with a 3-jaw chuck to hold each manufacturer’s driver was used. Force was applied to the wrench until either the spring style flexed to a precalibrated limit or the friction style released at a precalibrated torque value. The peak torque value was recorded by the digital torque gauge. This procedure was repeated 5 times for each wrench. Independent t test and one-way ANOVA (α = .05) were performed to compare different types of wrenches fabricated by different manufacturers.

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Results: The mean difference of torque values of different types of wrenches was not differed statistically significant (p = .084). However, mean difference torque values of Straumann wrenches showed lower values than others (p < .05). Other three manufacturers didn’t differ from each other (p > .05). Conclusions: Within the limitations of this study, different types of wrenches are not differed from each other. All wrenches of manufacturers show lower torque values than target torque values, but the lowest one was Straumann.

Poster Presentation No. 175 Immediate implant placement and provisionalization in the aesthetic zone

Konstantinos Tsoutis¹, Georgia Kalantzopoulou¹, Vasilios Chronopoulos² ¹University of Athens, Greece ²University of Griffith, Greece

Purpose: Implant-supported restorations are a conservative and predictable treatment solution for the replacement of missing teeth. When in the aesthetic zone, it is a challenge for the clinician to reproduce the original tooth shape and morphology, as well as the soft-tissues architecture. In selective cases of hopeless tooth extraction, immediate implant placement, bone grafting and provisionalization is an effective and predictable treatment option. The purpose of this poster is to present clinical cases treated with this protocol and to discuss its indications and advantages. Materials and Methods: Fractured or severely decayed anterior teeth were extracted and the alveolar socket was cleaned and evaluated. Implants were placed and the gap between implant and buccal bone was filled with FDBA bone graft. A provisional single-unit restoration was screwed on the implant at the same appointment. Special care was given to the emergence profile of the provisional in order to support the bone graft and the soft tissue scalloping. Definitive implant-supported crowns were placed four months later. Results: Treatment time reduction, immediate function and predictable aesthetics are the main advantages of this treatment protocol. Careful case selection is a prerequisite for treatment success. Conclusions: In cases with hopeless anterior teeth in the maxilla to be restored, when buccal bone plate is intact and primary implant stability can be achieved, immediate placement and provisionalization is a treatment plan with optimal aesthetic and functional outcomes.

Poster Presentation No. 176 Early implant failure – preliminary analyses of a large-scale patient material

Malin Olsson, Victoria Stenport, Torsten Jemt University of Gothenburg, Sahlgrenska Academy, Institute of Odontology, Sweden

Purpose: To analyse a large-scale patient material of implant treatments at one specialised clinic, regarding early implant failure in the edentulous jaw. Materials and Methods: Data on patients treated and followed-up with dental implants at one specialised clinic was compiled from 1986–2014. Totally edentulous jaws were analysed with respect to first implant failure up to one year after prosthesis placement (“early”). Data was statistically analysed on patient/surgery level by means of Chi-square tests. Results: Implants with a turned surface were inserted from1986 to 2003, thereafter replaced by implants with a moderately rough surface. Altogether 2039 and 2583 surgeries were conducted in edentulous maxillae and mandibles, respectively. Early implant failures were reported in 280 (18.3%) and 25 (4.9%) maxillae, showing a higher failure rate for turned surfaces (p < 0.001). Comparable numbers of early failures for mandibles were 77 (3.7%) and 13 (2.5%), respectively. A

145 39th Annual Conference of the European Prosthodontic Association significantly higher incidence of early implant failure in edentulous maxilla compared to edentulous mandible was observed, with turned (p < 0.001) and moderately rough (p < 0.05) implants, respectively. Patients with failures of implants with moderately rough surfaces placed in the maxilla had more frequently Cardio Vascular Diseases (CVD) compared to the corresponding group with turned implant surfaces (p < 0.05). Furthermore, patients with failures of implants with moderately rough surfaces placed in the mandible exhibited a higher prevalence of thyroid medication compared to the corresponding group with turned implants (p < 0.05). Conclusions: Early implant failure was significantly reduced with implants provided with moderately rough surfaces (p < 0.05). However, failures in these patients seemed to be more associated with CVD or thyroid medication (p < 0.05).

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10. LIST OF THE MAIN AND PRESENTING AUTHORS

Name Presentation Page Name Presentation Page Abbasov Elchin P-162 139 Cinel Sezgi P-136 126 Abdul Majeed Kais P-24 70 Cokuk Neslihan P-1 59 Abolfazli Nader P-43 80 Colgecen Ozlem P-132 124 Adimci Pinar O-10 33 Comlekoglu Erhan O-15 35 Agop-Forna Doriana O-36 46 Culhaoglu Ahmet Kursat P-8 62 Aktas Guliz P-126 121 Curt-Nazar Varol P-119 118 Al-Haj Husain Nadin O-22 39 Čimić Samir P-75 96 Alharbi Nawal O-24 40 de Baat Cees K-2 14 Altuntas Merveal P-132 124 Deda Ganimet P-95 106 Arnold Christin P-63 91 Dede Dogu Ömür P-64 91 Arslan Merve P-12 64 Degirmenci Kubra P-120 118 Artopoulou Ioli Ioanna O-45 50 Deniz Sule Tugba P-100 109 Assila Layla P-101 109 Dimopoulou Marina P-87 102 P-131 124 Dinçel Mehmet O-28 42 P-134 125 Disha Metush P-160 138 Ates Pinar P-84 101 Dogar Gokce P-128 122 Ayca Tulga P-109 113 Dřízhal Ivo K-20 24 Aydogdu Hasan Murat O-48 52 Dula Linda O-55 56 P-70 94 Dumitru Sirbu P-35 76 Ayse Gozde Turk P-33 75 Dumrul Fatmanur P-148 132 Ayyildiz Simel P-144 130 Eksi Hilal P-167 142 Babi Stella P-138 127 Elsheikh Nasr P-97 107 Baca Emrah P-61 89 Elter Bahar P-58 88 Barendregt Dick O-40 48 Emre Mumcu P-114 116 Barták Petr K-25 26 Erginsoy Tugce P-146 131 Barutcigil Kubilay P-4 60 Ergun Kunt Goknil P-16 66 Baumann Petra P-5 61 Erol B. Filiz P-92 105 Baysal Nurten P-91 104 Eskitascioglu Murat P-70 94 P-92 105 Etoz Onur P-53 85 Beldiman Maria-Antonela P-145 130 Fariba Saleh Saber P-44 81 Benke Beáta P-135 125 Foltán René K-4 15 Bilir Halenur P-13 64 Fonzar Alberto K-16 22 Bosinceanu Dan P-173 144 Forna Norina K-15 21 Bosinceanu D. Gabriela P-172 144 Galanopoulos Panagiotis P-34 76 Boztuna Aydan P-169 142 Gehrke Peter K-23 25 Bukovac Lea P-68 93 Groot Rob O-35 46 Burdinyashka Monika P-86 102 Güleç Ceyda P-154 135 Buyukerkmen Begum P-17 67 Güngör Hamiyet O-30 43 Buyukhatipoglu Isil O-9 32 Günsoy Selim P-66 92 Cakan Umut O-58 57 Habib Syed Rashid O-53 54 Çakirbay Taniş Merve O-12 34 Hassan Bassam O-5 30 Çalışkan Ahmet P-121 119 Hašková Eva P-90 104 Celakil Tamer P-166 141 Hatta Minori P-10 63 Celik Ersan P-65 92 Hayashi Shoji P-105 111 Celikkol Ongun P-148 132 Hazır Yadel P-157 137 P-158 137 Himmlová Lucie O-1 28 Cengiz Esra P-38 78 Hubálková Hana O-14 35 Ceyda Akin P-71 95 Chatzistavrianou Desp. O-19 38 Cilli Mesutcan P-115 116 İdris Kavut P-124 120

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Name Presentation Page Name Presentation Page İlgi Baran P-55 86 Matsuyama Miwa P-27 72 Ishigaki Shoichi P-74 96 Melescanu-Imre Marina P-103 110 Jercan Larisa O-33 45 Merve Aytuğ P-171 143 Jussila Päivi P-69 94 Mostovei Mihail P-35 76 K.C.Basnyat Smriti O-31 44 Mumcu Emre P-106 112 Kalantzopoulou Georgia P-110 114 P-114 116 Kale Ediz P-107 112 Mutlu Ali P-116 117 Kamberi Blerim O-57 57 Muzsek Zsófia P-46 82 Kamposiora Phophi P-127 122 Mylonas Petros O-2 28 Kan Melike P-52 85 Närhi Timo K-10 18 Kanat Ertürk Burcu P-149 132 Natsios Giannis P-150 133 Kapogianni Christina P-112 115 Nayar Suresh K-19 23 Kara Haluk Baris O-7 31 Nikitina Evija P-14 65 P-96 107 Oki Kyosuke P-37 77 Karci Muhammet P-102 110 Okutan Yener O-13 34 Karl Matthias P-170 143 Oliveira Marcondes P-82 100 Kazazoglu Ender P-3 60 Olsson Malin P-176 145 Kazuyoshi Baba P-49 83 Omran Tarek Ashraf P-56 87 Kilic Ismail O-13 34 Otsuka Hidetoshi P-76 97 Kilinç Halil İbrahim O-29 43 Özarslan Mehmet P-9 62 P-174 144 Özcan Mutlu O-22 39 Kırmalı Omer P-48 83 P-129 123 P-72 95 Ozdere Eda O-46 51 Kirstein Karol P-62 90 Ozdogan Mahmut Sertac P-29 73 Kiswani Mohannad O-23 40 Ozen Julide P-83 100 Kiviahde Heikki P-67 93 Ozevcimen A. Nagehan P-11 64 Knaus Anna K.13 20 Ozgur Inan P-71 95 Kocak Imran P-152 134 Öztürk Özgür P-15 65 Komiyama Osamu P-50 84 Papanagiotou Polykarpos O-37 46 Köroğlu Ayşegül P-89 103 Papathanasiou Ioannis P-127 122 Köroğlu Kale Aslıhan O-49 52 P-139 128 Kranjcic Josip P-94 106 Papavasiliou George K-11 19 Krug Jiří K-9 18 Pasali Baris P-2 59 Kříž Pavel K-6 16 Patil Pravinkumar P-93 105 Küçükekenci A. Serkan P-137 126 Persic Sanja P-22 69 Kučera Josef K-18 23 Pietrokovski Jaime O-25 41 Kuris Bastan Esma P-122 119 Pietrokovski Yoav O-25 41 Kurt Meral P-133 124 Pihlaja Juha P-73 95 Kurtulmus Yilmaz Sevcan P-72 95 Piskin Bulent P-117 117 Kurugöl Pelin Inan O-7 31 Pjetursson Bjarni E. K-3 15 Lamprinoudi Angeliki P-155 136 Pozidi Georgia P-151 134 Lieshout Hendrik P-99 108 Pustina-Krasniqi Teuta O-42 49 Lila-Krasniqi Zana P-88 103 Qafmolla Alketa O-54 55 Linetskiy Igor O-4 29 Qiting Huang P-20 68 O-14 35 Rajnics Zsolt P-156 136 Linssen Marcel O-43 49 Ravenshorst Marliek O-44 50 Loster Jolanta E. P-25 71 Reeves Juliette K-14 21 Lugovskoy Svetlana P-79 98 Rinke Sven O-6 31 Mackeviciute Monika P-36 77 Şahin Onur P-18 67 Marek Ivo K-7 17 Şahinbaş Abdurrahman O-11 33 Markovics Dóra P-54 86 Sailer Irena K-21 24 Martinez-de F. Rafael O-47 51 Salinas Thomas J. K-1 14 Matsuda Risa P-39 78

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Name Presentation Page Name Presentation Page Saraç Duygu P-2 59 Ustun Ozlem O-9 32 P-80 99 P-48 83 Sarafianou Aspasia O-52 54 van Pelt Hans O-34 45 Sato Maki P-41 79 Vavřičková Lenka O-18 37 Sato Yohei P-141 128 Verner Miroslav K-26 26 Sazvar Haniyeh P-59 88 Vinkenborg Carolien O-51 53 Sazvar S.M.R. O-32 44 Viskic Josko O-16 36 Seçkin Anıl P-140 128 Vitalie Pantea P-159 138 Sedláčková Radmila O-38 47 Wagemakers Pieke O-41 48 Seker Basak Kusakci P-108 113 Walls Angus K-8 17 Seker Emre P-8 62 Waning Albert K-24 26 P-106 112 West Nicola K-12 19 P-108 113 Wieczorek Aneta P-40 79 Setz Jürgen K-5 16 Yagci Ahmet P-142 129 Sevimay Müjde P-30 74 Yagci Filiz P-143 129 Shahramian Khalil P-57 87 Yaman Gizem O-15 35 Shala Kujtim O-60 58 Yeliz Hayran P-161 139 Shaqiri Sherif O-56 56 Yenice Neslihan P-113 115 Shinya Akikazu P-26 71 Yenisey Murat P-153 135 Shojae Razavi Alaleh P-130 123 Yeo In-Sung P-81 99 Schryvers Alexander O-50 53 Yfanti Afroditi P-118 117 Sibel Dikicier P-78 98 Yıldız Pınar O-28 42 Sipahi Cumhur O-27 42 Yilmaz Burcu P-96 107 Siti Mariam Ab Ghani P-98 108 Yılmaz Evmek Betül P-147 131 Sokolowski Alwin Alan P-163 139 Yilmaz Tuba O-20 38 Soualhi Hicham P-134 125 Yurchenko Maksim O-3 29 Spule Daina P-28 72 Zokaris Nikolaos P-60 89 Spyridon Stefos P-51 84 Zouheir Ismaili P-131 124 Spyropoulos Dionysios P-111 114 Staka Gloria P-31 74 Stanojevic Mihael P-19 68 Strajnic Ljiljana P-21 69 Subaşı Meryem Gülce P-102 110 Šimůnek Antonín K-17 22 Šmucler Roman K-22 25 Tabatabaian Farhad O-21 39 P-104 111 Tak Onjen P-123 120 Taşar Simge O-8 32 Tatar Numan P-45 81 Teshigawara Daisuke P-77 97 Tmava-Dragusha Arlinda P-164 140 Tokue Ai P-23 70 Tomic Slavoljub P-125 121 Traistaru Teodor P-7 61 Tsoutis Konstantinos P-175 145 Tsujimoto Akimasa P-85 101 Ulusoy Mutahhar M. P-66 92 Ulusoy Nuran P-47 82 Ünver Senem P-32 75 Ural Çağrı P-165 141 Urbanová Wanda O-39 47

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11. EPA 39th ANNUAL CONFERENCE PARTNERS

Golden partner: Philips Česká republika, s.r.o.

Partners: ADM, a.s. Dentamed (ČR), spol. s r.o. Dentsply Implants EveryDent, s.r.o. Intensiv SA JPS, spol. s r.o. KaVo Kerr Group 3M Česko, spol. s r.o.

The EPA 2015 congress organizer is grateful to all partners and their contributions.

150 39th Annual Conference of the European Prosthodontic Association

39th Annual Conference of the European Prosthodontic Association

Team of authors

Pictures: Repository of authors

Published by Czech Society of Prosthetic Dentistry and Czech Dental Chamber

Slavojova 22, 128 00 Praha 2, Czech Republic

IČO 67361790

www.protetickaspolecnost.cz

www.dent.cz

1st edition, September 2015

Editorial board: doc. MUDr. Hana Hubálková, Ph.D., doc. MUDr. Marie Bartoňová, CSc.

Typesetting and typography: Radim Vaněk

Printed by: TISK SPRINT, s.r.o.

ISBN 978-80-260-8581-2

152 Beyond CAD/CAM Patient-specific prosthetic solutions for all major implant systems

In order to provide truly ideal solutions, you need restorative versatility, flexibility within your workflow and design options that are as individual as each patient. By choosing ATLANTIS, you get the freedom, esthetics, simplicity and reliability that go beyond CAD/CAM. DENTSPLY Implants does not waive any right to its trademarks by not using the DENTSPLY symbols Implants. ® or 32670848-USX-1504 © 2015 ™. All rights reserved

www.dentsplyimplants.com www.jps.cz

3OB.indd 1 20.8.2015 17:30:52 Golden partner

Partners

Published by Czech Society of Prosthetic Dentistry and Czech Dental Chamber Prague, Czech Republic ISBN 978-80-260-8581-2

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