ISPRD Abstracts 10/4/07 11:57 AM Page 488

ISPRD abstracts 10/4/07 11:57 AM Page 488

488 The 9th International Symposium on Periodontics & Restorative Dentistry

June 7–10, 2007 Boston, Massachusetts Poster Abstracts

No. 1 ment. Once the implants were healed, the zirconia implant-fixed Clinical Advantages of Fixed Provisionalization in Atrophic maxillary complete denture was fabricated according to Ridges Utilizing Transitional Implants. W. Kim, A. Koa, S. Villareal, ZirkonZhan protocol. Discussion: Biological or mechanical compli- S. Cho, S. Froum, N. Elian, D. Tarnow (New York, New York) cation may exist during the lifetime of the prosthesis. According to the literature, mechanical complications are the most common Introduction: Ridge deficiencies in the edentulous alveolar ridges in implant prostheses. These mechanical complications may be may preclude ideal implant placement. To solve this problem, a caused by inaccuracy of fabrication or by the characteristics of the variety of ridge augmentation procedures have been proposed. materials used. The ZirkonZhan milling unit device was catego- Regardless of the surgical modality, undisturbed healing for rized as part of the CAD/CAM technology and is believed to be grafted ridges and subsequent implant placement is critical to very accurate. Zirconium oxide has demonstrated less bacterial achieving a successful result. The use of transitional implants (TIs) adhesion and has self-repairing properties, meaning that it pre- before ridge augmentation allows the clinicians to provide stable vents crack propagation by a phenomenon called “transformation fixed temporary prostheses throughout the treatment period, toughening.” Zirconium oxide ceramic has also proven easier to while keeping transmucosal forces from being placed on the repair, even after being in situ for a period of time. New designs grafted ridge. The TI support provisional also maintains soft tissue for implant-supported fixed complete dentures are now possible architecture and ensures that the final implant is in the ideal with new dental technology; however, this technology remains esthetic position. The TIs placed with immediate loading may too new to provide for long-term studies. Conclusions: This novel enhance the quality of surrounding bone. Purpose: The purpose design using CAD/CAM technology and zirconium oxide as a of this report is to retrospectively evaluate the survival rate of restorative material can result in optimum restoration with very fixed provisionals utilizing transitional implants in atrophic ridges good esthetics and long-term durability. Disclaimer: There was no and discuss the clinical advantages of this modality. Materials and commercial support for this study. Methods: Nine consecutive clinical cases with 20 transitional implants were followed for a period of 4 to 36 months. Ridge No. 3 augmentation procedures were performed on each patient, final Bone Healing Following Osteotomy: A Comparison of CO2 implants were placed, and final restorations were delivered. Laser, ER:YAG Laser, Ultrasound, and Saw Techniques. Results: All TIs lasted through the ridge augmentation procedure S. Stübinger, B. von Rechenberg, J. Kuttenberger, P. Hering, H. and the maturation period and until the permanent implants were Zeilhofer, R. Sader (Frankfurt, Germany and Basel, Switzerland) loaded. There was no failure of fixed provisional restorations and also no failure of the final restorations from their initial placement Background and Purpose: Surgical reconstruction of bony defects until the final follow-up. Conclusion: The use of transitional in oral and maxillofacial surgery is often very challenging, as thin implants allows the fixed provisionals to maintain soft tissue archi- and fragile bony structures are especially prone to fracture due to tecture, and, at the same time, ensures that the final implant will massive application of pressure by conventional mechanical instru- be in the ideal esthetic position. ments. Noncontact, blood- and vibration-reduced laser surgery with free choice of cut geometry and the prevention of massive No. 2 bone flour and metal abrasion is to the best advantage in this Zirconia Implant-Supported Fixed Maxillary Complete Denture: regard. The aim of this animal study using sheep was to investi- A Novel Design Using the ZirkonZahn Protocol. E. Grageda gate the bone healing process after the use of two laser systems in (Mexico City, Mexico) comparison to two mechanical osteotomy techniques. Materials and Methods: A midshaft osteotomy of the tibia diaphysis was Introduction: The implant-fixed complete denture is a well-recog- performed on all 44 sheep. In one group of 12, a pulsed Er:YAG nized treatment for the edentulous patient. This type of prosthesis laser (Fidelis Plus, Fotona, Ljublijana, Slovenia; pulse energy 1000 can be fabricated using a combination of different designs, tech- mJ, pulse duration 300 µs, pulse frequency 12 Hz) was used. In niques, and materials. Today CAD/CAM technology is replacing another group of 12, an ultrasound device (Piezosurgery, Mectron; the conventional cast gold alloy technique for framework fabrica- saw blade OT7, mode boosted burst C, pump 5) was used. In a tion since it is more accurate, cost effective, and it allows the use third group of 12, practioners used a conventional saw blade of more materials. Zirconium oxide was introduced to dentistry (Synthes, Switzerland). The fourth group consisted of eight sheep because of its excellent chemical stability, high mechanical load- treated using a new computer-assisted prototype CO2 laser (pulse ing, outstanding biocompatibility, and unique esthetic qualities. energy 80-85 mJ, pulse duration 80 µs, pulse frequency 200-400 ZirkonZhan is a new milling unit device that can read and mill all Hz). After 2 and 3 months, specimens were evaluated by radio- types of framework shapes by using its novel “five-axis” system. graphic and histologic analysis. Polychrome sequence labeling and Materials and Methods: A 65-year-old man came to the clinic histomorphometry were also performed. Results: Thermal damage with the chief complaint of mobility of all maxillary teeth. All the at the osteotomy sites was comparable in noncontact laser and teeth were diagnosed with advanced marginal periodontitis and mechanically cut bone fragments. In contrast to former studies, no were considered hopeless. All maxillary teeth were extracted, and severe carbonization and no wound healing impairments resulted an immediate complete denture was given to the patient. After a from the use of the new CO2 laser system. The laser system few months of healing, a computerized planning and virtual fabri- allowed for unprecedented preciseness and cut geometry, cation of the prosthesis was performed for proper implant place- although the system required the most time, and handling had to

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be more intricate in contrast to the other procedures. growth factors and fibrin matrices combined with particulate Osteotomies performed by ultrasound and Er:YAG laser resulted bone allograft. A histological analysis was performed to evaluate in precise and smoothly cut edges with an ingrowth of vital bone- bone quality. Methods: Ten patients (10 maxillary anterior ridge forming tissue into the osteotomy gap after 2 months. Additional defects) were treated utilizing autologous growth factors (FGF, radiologic and fluorescence labeling data supported these find- IGF-I, PDGF, TGF-;98;, EGF, VEGF, HGF) and fibrin matrices ings. However, histologic evaluation demonstrated no significant combined with particulate bone allograft. Soft tissue gain was difference in the amount of newly formed woven bone at the measured at baseline; 7 days; and 1, 3, and 6 months postsurgi- osteotomy site made by Er:YAG laser/Piezosurgery or conven- cally. At 6 months prior to dental implant placement, bone biop- tional saw. In all four groups, defects healed by 12 weeks postop- sies were taken, and the quality of the bone at the regenerated eratively. Conclusion: For use in osteotomies of thin and fragile sites was analyzed histologically. Results: At 7 days postopera- bones in the maxillofacial region, Er:YAG laser irradiation and tively, soft tissue width gain was 3.57 mm (P = .001 with a confi- ultrasound techniques are superior to saw and CO2 laser tech- dence interval of 95% (3.19 ± 3.90 mm), and height gain was 3.2 niques because of their easy handling, efficient bone ablation, and mm (CI 95%, 2.63 ± 3.63 mm). Adequate soft tissue healing and minimal accidental harm to adjacent soft tissue structures. wound closure was also observed. At 1 month, soft tissue width Nevertheless, computer guidance of a laser beam allows newly gain decreased to 2.63 mm (P = .001, CI 95%, 2.32± 2.95 mm), arranged, arbitrary, and self-stabilizing osteotomies, which could and height gain to 2.60 mm (CI 95%, 2.24 ± 2.96 mm). At 3 be enhanced by navigation systems and robotics. months, width gain remained stable at 2.63 mm (CI 95%, 2.32 ± 2.95 mm), and height gain at 2.60 mm (2.24 ± 2.96mm). At 6 No. 4 months these values remained unchanged, and histologic analy- Outstanding Clinical and Human Histologic Outcomes with the ses of bone biopsies showed bone formation with osteocyte lacu- PerioLase Nd:YAG Laser. R. Yukna (Aurora, Colorado) nae, vital osteocytes, thin bone appositional lines, haversian canals, osteoblasts, and osteiod formation. Conclusions: These Introduction: The Laser Assisted New Attachment Procedure results showed that tissue augmentation therapy utilizing autolo- (LANAP) using the Nd:YAG laser has been developed for the sul- gous growth factors and fibrin matrices, combined with particu- cular debridement of periodontal pockets with the goal of late bone allograft, translated to significantly improved esthetic obtaining new attachment. Favorable clinical results have been results and implant success in tissue-regenerated sites. Further reported, but human histologic proof of new attachment or studies with a larger sample are needed to enhance the statistical regeneration is limited. Purpose: To evaluate the histologic significance of our clinical and histological findings. wound healing in periodontal pockets in humans following treatment with the LANAP protocol. Methods: Six pairs of single- No. 6 rooted teeth with moderate to advanced chronic periodontitis Full-Arch Immediate Implant Placement for Optimal Immediate associated with subgingival calculus deposits were treated. Function in Periodontally Compromised Patients. C. Coutinho Occlusal adjustment and direct bond extracoronal splinting were Alves (Porto, Portugal) performed. Under local anesthesia, a 1/4 round bur notch was placed at the apical extent of calculus as carefully as possible. Introduction: Periodontally compromised patients, especially One of each pair of teeth received pulsed free running Nd:YAG young adults needing a full-arch implant-supported rehabilita- laser treatment of the inner pocket wall to remove the pocket tion, are, most of the time, candidates for immediate implant epithelium (3 watts, 150 pulses/second, 10 hz). Both teeth were placement followed by immediate function. Purpose: To avoid then aggressively scaled and root planed with an ultrasonic scaler the necessity of a removable provisional prosthesis, and to pre- and hand instruments. The pockets of the test teeth were lased serve the patient’s functional outcome, esthetics, and quality of again to help coagulate any blood present and to form a fibrin life, we have developed a clinical protocol to treat periodontally seal. Triple antibiotic ointment and a light-cured dressing were compromised patients presenting full-arch irreversibly lost denti- placed. The control teeth received all of the above except the tion: the complete full-arch extraction and its immediate replace- laser treatment. The patients were seen every 10 days for the first ment by a provisional acrylic fixed implant-supported complete month, then at 2 and 3 months, at which time the treated teeth denture. In this poster presentation we will describe, step by were removed en bloc for histologic processing. Decalcified step step, all the clinical (surgical and prosthetic) phases of the proto- serial sections were stained with H&E. Results: All six of the col, illustrating it with a clinical case with 3-year follow-up. LANAP treated specimens showed new cementum and new con- Materials and Methods: A 40-year-old female, nonsmoking nective tissue attachment (and in two cases new bone and new patient was referred to us for the rehabilitation of her maxillary periodontal ligament) in and coronal to the calculus notch. New teeth. All 11 maxillary teeth showed severe bone loss and mobil- cementum length averaged 1.2 mm. The control teeth had a long ity. Our optimized treatment plan was to extract every tooth and junctional epithelium with no evidence of regeneration. There immediately place 10 implants (Nobel Biocare TiUnit MK III ␾ was no evidence of any adverse pulpal or tooth surface changes 3.75 RP). In the same surgical step, bilateral sinus lift was done in any specimen. Conclusion: This case series supports the proof using a Bio-Oss (Osteohealth) + plasma-rich growth factors of principle that LANAP can be associated with cementum-medi- (PRGF) graft with the simultaneous placement of two implants in ated new attachment (and occasionally true periodontal regener- each sinus. The other six implants were placed as follows: two in ation) on a diseased root surface in humans. Consistently positive the alveolar sockets of the central incisors, two in the canine alve- histologic results were found in six of six LANAP treated teeth. olar sockets, and two in the first premolar alveolar sockets. A pro- Acknowlegment: Supported by Millennium Dental Technologies, visional acrylic fixed implant-supported complete denture was Inc, and the Louisiana State University School of Dentistry made and adapted to the six implants in the first 24 hours, spar- Periodontics Miscellaneous Donors Fund. ing the other four implants that had been placed in the maxillary sinus graft material. After 4 months, definitive impressions were No. 5 taken, and a definitive ceramic fused-to metal complete implant- Tissue Augmentation Utilizing Autologous Growth Factors and supported denture was made and screwed to all 10 implants. Fibrin Matrices in Combination with Particulate Bone Allograft Results: None of the 10 immediately placed implants was lost. for Dental Implant Placement: Clinical and Histological Evidence. The 3-year follow-up radiographic control showed great bone- M. Restrepo (Bogotá, Columbia) implant contact of all 10 implants and perfect adjustment of the prosthetic components. The clinical 3-year follow-up showed an Introduction: Tissue augmentation is a predictable procedure for optimal esthetic and stable final result. Discussion/Conclusion: increasing soft and bone tissue volume. Studies show that growth The purpose of using “Immediate Placement & Immediate factors have the potential to promote wound healing, tissue Function” in patients with full-arch periodontal compromise is to repair, and regeneration. Purpose: To evaluate width and height minimize the psychological and functional consequences of a full- of tissue gain with regenerative therapy utilizing autologous arch natural dentition extraction. By following extraction with the

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immediate placement of implants and by using the PRGF to pro- amount of bone formation than Group AB (64.44% and 46.88%, mote healing, we obtain an optimized preservation of the residual respectively). At 90 days, complete bone regeneration of the bone as well as the ideal soft tissue maturation. The purpose is, defects was seen in all specimens of Groups AB/PRP and AB, with also, to optimize the final esthetic result. Placing an immediate similar amounts of newly formed bone (77.9% and 75%, respec- provisional implant-supported fixed denture prevents potential tively). It is notable that the amount of new bone formation in secondary bone loss during the implants’ osseointegration phase. Group AB/PRP at 30 days was similar to that of Group AB at 90 It also guides the soft tissue emergence profile around implants days. Conclusion: Within the limits of this study, it can be con- and modulates the pontic sites (ovoid pontics). cluded that PRP accelerated the healing of autogenous bone graft in critical-size defects in rabbit calvaria. Acknowledgment: No. 7 This study was partially supported by BIOMET/3i. Biologic Factors Involved in the Osseointegration of Oral Titanium Implants Positioned using Piezosurgery Versus a Drill No. 9 Technique: A Pilot Study in Minipigs. G. Preti, G. Manzella, R. Anorganic Bone Mineral Coated with Tetra-Cell Adhesion Navone, C. Russo, R. Canuto G. Schierano (Turin, Italy) Molecule Enhances Differentiation of Osteoblast-like Cells and Bone Formation. J. Park, S. Kang, O. Joeng, J. Lee, S. Yeo, I. Introduction: Rotating drills increase temperature during oral Kim, J. Suh (Daegu, Korea) implantology, and the resulting protein denaturation may have a negative effect on the bone healing process; meanwhile, maxil- Introduction: The current development of tissue engineering lary osteotomies performed using piezoelectric surgery have makes it possible to envision the association of autologous cells demonstrated that this instrument allows for precise surgery while and/or proteins that promote cell adhesion with osteoconductive simultaneously protecting delicate anatomic structures. This study material to create bioactive materials. The most commonly used compares the osseointegration of porous implants positioned peptide for surface modification is RGD, the signaling domain using drills and piezosurgery. Methods: Porous titanium implants derived from fibronectin (FN). FN binds to the integrin family were inserted into the tibias of eight minipigs. The animals were through a consensus site that contains the RGD sequence within sacrificed at 7, 14, 28, and 56 days post-implantation. Histological the tenth type III domain. The PHSRN sequence in the ninth type analysis and levels of bone morphogenetic proteins (BMP-4 and III domain serves as a synergistic site that enhances the binding BMP-7), transforming growth factor (TGF)-;98;2, tumor necrosis affinity of the RGD sequence. Also, ␤ig-h3 is a cell adhesive pro- factor (TNF)-␣, interleukins (IL-1␤ and IL-10), and osteocalcin were tein whose expression is highly induced by TGF-␤ in several cell evaluated in the peri-implant osseous samples. Results: Histologic types. ␤ig-h3 has been considered to promote cell adhesion and analysis showed that the inflammatory cells were more numerous spread through EPDIM of the 4th fas-1 domains and YH present in samples coming from the drilled sites than from piezosurgery in each of the fas-1 repeat domains. Materials and Methods: We sites. Neo-osteogenesis was consistently more active in the bone synthesized tetra-cell adhesion molecule (T-CAM), which is the samples from the implant sites prepared using piezosurgery com- recombinant protein containing an RGD sequence in tenth type III pared with the drilled sites. The bone around the implants treated domain, a PHSRN sequence in the ninth type III domain of with piezosurgery showed earlier increases in the levels of BMP-4 fibronectin, and YH sequence and EPDIM sequence in fourth fas- and TGF-␤2 bone repair proteins, reduced expression of pro- 1 domain of ␤ig-h3. Purpose: The purpose of this study was to inflammatory cytokines, and delayed osteocalcin synthesis. evaluate the cellular activity of osteoblast-like cells to anorganic Conclusions: Based on these results, we hypothesize that piezo- bone mineral (ABM) coated with T-CAM and the effect of ABM surgery is more efficient than drill surgical treatment because it is coated with T-CAM for bone formation in rabbit calvarial defects, minimally invasive, is precise, and could be used for the immedi- while comparing the results with those of ABM. Additionally, we ate loading technique. investigated the bone healing response to T-CAM–coated and uncoated rough-surfaced titanium implants, produced by hydrox- No. 8 yapatite (HA) blasting, placed in areas with poor local bone. Effects of Platelet-Rich Plasma on Bone Healing with Autogenous Conclusion: We suggest that the presence of T-CAM remarkably Bone Grafts in Critical-Size Defects: A Histologic and Histometric affected the differentiation of osteoblast-like cells grown on HA Study in Rabbit Calvaria. M. Nagata, L. Melo, M. Messora, S. and significantly increased the new bone formation in the rabbit Bomfim, S. Fucini, V. Garcia, A. Bosco (Araçatuba, Brazil) calvarial defects. Also, the T-CAM coating on the rough-surfaced titanium implants significantly enhanced peri-implant bone forma- Introduction: Researchers continually strive to improve bone tion in rabbit femurs with poor local bone condition. grafting techniques in order to achieve faster and denser bone Acknowledgment: This work was supported by grant No. regeneration. Marx et al (1998) have proposed the use of platelet- (M10646020001-06N4602-00110) from the national research and rich plasma (PRP) to obtain faster maturation of autogenous bone development program of MOST/KOSEF. grafts. Since then, contradictory results have been reported in both clinical and animal studies. Purpose: The purpose of this No. 10 study was to histologically analyze the effect of PRP on bone heal- Histologic and Histomorphometric Evaluation of Human ing in autogenous bone grafts placed in surgically created critical- Maxillary Sinus Floor Augmentation Using Different Bone- size defects (CSD) in rabbit calvaria. Materials and Methods: 60 Grafting Materials. Y. Hsieh, A. Tsai, C. Liu (Taiwan) rabbits were divided into 3 groups: C (control), AB (autogenous bone graft), and AB/PRP (autogenous bone graft with PRP). A 15- Introduction: Oral rehabilitation around the edentulous posterior mm-diameter CSD was created in the calvarium of each animal. In region of maxillae with dental implants may be difficult because Group C the defect was filled by blood clot only. In Group AB the of insufficient bone volume caused by crestal bone atrophy and defect was filled with particulate autogenous bone. In Group pneumatization of the maxillary sinus. Different bone-grafting AB/PRP it was filled with particulate autogenous bone in combi- materials have been used for sinus floor augmentation by many nation with PRP. The mitogenic activity of the PRP was verified in dentists. Purpose: The purpose of this clinical study was to evalu- vitro. All groups were divided into subgroups (n=10) and eutha- ate new bone quality following sinus augmentation with various nized at either 30 or 90 days postoperative. Histometric (using graft materials (Cerasorb [Curasan] only or in combination with image analysis software) and histologic analyses were performed. autogenous bone, FDBA, or in combination with Bio-Oss The amount of new bone was calculated as a percentage of the [Osteohealth] and autogenous bone) in sinus floor augmentation total area of the original defect. Percentage data were trans- performed as two-staged procedures. Materials and Methods: A formed into square root for statistical analysis (ANOVA, t test, P < total of 10 patients participated in this study. Inclusion criteria .05). Results: Group C presented significantly less bone formation were partial maxillary edentulism (unilateral or bilateral) involving than either Group AB or AB/PRP at both periods of analysis. At 30 the molar area and less than 5 mm of remaining crestal bone days postoperative, Group AB/PRP had a statistically greater between sinus floor and alveolar ridge. There were four grafting

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materials inserted purely or in combination. Each patient under- implants and teeth were performed after patients’ periodontal dis- went biopsy during the operation of implant placement surgery ease was re-evaluated. Final restoration took place an average of 4 after 6 months. Eleven specimens were taken from implant sites months after surgery. Results: Patients were evaluated clinically then evaluated histologically and histomorphometrically. Results: and radiographically at the time of implant placement and at 2, 6, There were no postoperative complications in any of the patients. and 12 months. Inflammation of gingiva, radiographs of bone The initial stability of all implants was excellent, including that of resorption, and Periotest values were assessed. Patients were two cases combined with GBR during implant placement. placed in the following categories: excellent (all conditions satis- Histological findings revealed that almost all particles of graft factory); good (two conditions satisfactory); fair (one condition sat- materials (Cerasorb, FDBA, Bio-Oss, autograft) were surrounded isfactory), and poor (implants were lost and a second surgery was by newly formed bone. No inflammatory cell infiltration or osteo- necessary). At 2 months, 97.4% of the implants remained osseoin- clasts were found in the specimens. Newly formed bone with tegrated. Twelve months after surgery,70 implants (92.10%) were lamellar arrangements was identified in all specimens, especially evaluated as “excellent” (23 anterior, 47 posterior), 4 (5.26%) on occlusal surfaces. The amount of new bone was decreased implants were rated “good” (4 posterior), no implant was rated from peripheral to deeper zone. The range of the newly formed “fair,” and 2 posterior implants (2.63%) were rated “poor.” The bone volume was 30% to 45%. Conclusion: All bone-grafting “good” group showed gingival recession. Implants in the “poor” materials used in this clinical study were biocompatible and group were lost because of broken provisional restorations and seemed to provide stable space-making ability for bone regener- implant mobility and were replaced. HA bone materials and rough ation in sinus floor augmentation. The data suggest that autoge- surface seemed to stop bone recession. All patients were satisfied nous bone, Cerasorb, FDBA, and Bio-Oss are all satisfactory graft- with this treatment. Minor alternation of both the bone and gin- ing materials for sinus floor augmentation and that such a giva continued for 1 year, but did not progress. Conclusion: procedure is clinically reliable. Immediate implant loading with simultaneous guided bone regeneration is a successful method for patients who have lost function, No. 11 bone resorption, and tooth esthetics. Well-developed surgical Tooth-and-Tissue-Supported Transitional Fixed Partial Dentures. techniques and sophisticated prosthetic treatment are key to a V. Chronopoulos, S. Kourtis (Athens, Greece) successful outcome; periodontal and anatomic diagnosis, implant designs, and prosthetic plans are also very important. The follow- Introduction: Restoration with implants for edentulous patients is ing protocols are proposed: (1) Stabilize bone with long implant an increasing demand in clinical practice. Although there is a clini- apex. (2) Use graft materials (ie, nonabsorbable HA material) for cal tendency for immediate loading of the implants, the standard the scaffold. (3) Use provisional restorations that prevent pressure protocol for delayed loading is always applied. During the and irritation on tongue and oral mucosa. (4) Cover the GBR area osseointegration period, restoration with complete dentures is with a periosteum (rather than a barrier membrane). (5) Fix provi- the traditional treatment for fully edentulous patients; however, sional restorations with a solid abutment and cementation; limit complete dentures are associated with numerous complications in micromovement with screw retention. the healing period, including early implant uncovering, soft tissue pressure, peri-implant bone loss, etc. Materials and Methods: No. 13 The use of transitional fixed partial dentures supported by hope- New Bone Formation Improved by Angiogenic Factor in less teeth that will be extracted at the end of the osseointegration Enriched Platelet-Rich Plasma. E. Park, E. Kim, D. Mooney period can offer significant clinical advantages by avoiding many (Daejeon, Korea and Cambridge, Massachusetts) clinical problems. Additionally, the transitional restoration can be supported by soft tissues in the retromolar or tuberosity area. The Introduction: Although most researchers agree that platelet-rich use of two teeth in the anterior region and supporting metal- plasma (PRP) is a good source of autogenous growth factors, its acrylic pads in the retromolar region can offer adequate support effect on bone regeneration of acellular bone substitute is still for the time needed until implant uncovering. Restoration with controversial and sometimes disappointing. Purpose: The pur- this type of transitional fixed partial dentures includes construc- pose of this study was to improve osteogenic potential of PRP tion of a metal framework to support the polymer veneering through enhancing its angiogenic characteristics (angiogenic fac- material. Purpose: The purpose of this poster is to present the tor–enriched PRP). Materials and Methods: The PRP effect in new clinical and laboratory stages for the construction of tooth-and-tis- bone formation was evaluated with alloplastic graft material and sue-supported transitional fixed partial dentures with examples of with suboptimal concentration of bone morphogenic protein-2 clinical cases. (BMP-2) in vivo. The preparation method for angiogenic factor–enriched PRP was focused on four factors: (1) activation of No. 12 platelet with minimal amount of thrombin and calcium, (2) initial Immediate Implant Loading with Simultaneous Guided Bone vascular endothelial growth factor (VEGF) liberation, (3) formation Regeneration: 76 Case Reports. N. Matsumoto, S. Yosida (Tokyo, of platelet microparticles (PMPs), and (4) incorporation of periph- Japan) eral blood mononuclear cells (PBMNCs) and exclusion of poly- morphonuclear leukocytes (PMNs). For these, shear stress and a Purpose: The aim of this case report is to evaluate 76 implants that small amount of collagen (20 µg/mL) were used for pre-activation were immediately loaded with simultaneous guided bone regener- of platelets, and density gradient medium (Ficoll-Paque [GE ation, and to propose protocols for this procedure. Materials and Healthcare]) was used for separation of MNCs. In vitro, the Methods: Thirty patients (10 male, 20 female) with an average age amount of growth factor released from platelets, cell proliferation, of 53 (range 37 to 86) were included in this study. Twenty-two and osteogenic differentiation were evaluated among various PRP implants were placed in the anterior region and 44 implants were preparation methods. In vivo, PRPs were grafted into cranial placed in the posterior region. In most cases, teeth were removed defects of 28 athymic rats with ␤-tricalcium phosphate (␤-TCP) or because of periodontal disease and poor bone condition, and human recombinant bone morphogenetic protein-2 (rhBMP-2) in immediate implant loading and guided bone regeneration were polyglycolic acid scaffolds. Results: Angiogenesis and osteogene- performed during the same surgery. Seventy-two implants were sis were evaluated by LDPI, histology, DEXA, and µCT at 2 and 8 Straumann SLA, and four implants were Nobel Biocare. Initial peri- weeks respectively after the surgery. As a result, angiogenic fac- odontal preparation was performed completely. In one operation, tor–enriched PRP showed increased blood flow of regenerating periodontal surgery and tooth extraction were performed, provi- tissue. Also, they accelerated new bone formation around allo- sional restorations were cemented on Solid (Straumann) or Easy plastic graft material, and its effect was significantly augmented (Nobel Biocare) abutments, immediate implant loading and by rhBMP-2 compared with PRPs prepared by conventional meth- guided bone regeneration were performed, and hydroxyapatite ods. Conclusion: PRP focused on its angiogenic potential (HA) and autogenous bone chips were placed around implants. enhanced bone formation through improved vascularity around Postoperative maintenance followed, and final restoration of the defect during the healing.

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No. 14 low radiation dose (80 kV, 4 mA), and three-dimensional images Immediate Loading of Zygomatic Implants in the Severely (0.125-mm voxel resolution). It gives very clear images before Atrophic Maxilla. M. Gatti, T. Suda, S. Hate, M. Papageorge, R. treatment. The range of slice thickness of 3DX is: 0.125 mm, Chapman (Boston, Massachusetts) 0.250 mm, 0.500 mm, 1.000 mm, 1.500 mm, and 2.000 mm. Analysis of the mandibular bone was carried out in a 0.125-mm to Introduction: Osseointegrating dental implants placed in the 0.500-mm slice—the thick region of the mandibular incisors in the zygomaticus bone have long been utilized to aide in reconstruc- sagittal section. The microscope enables the surgeon to assess tion of craniofacial defects following ablative surgery, trauma, and pathological changes more precisely and to remove pathological congenital syndromes. These implants have significantly improved lesions with far greater precision, thus minimizing tissue damage the quality of life of patients. In 1989 Brånemark et al applied simi- during surgery.. After assessing 14 patients ranging in age from lar techniques to help those with significant resorption of the max- 18 to 43, the author found that using microscopes had refined illa via the use of elongated versions of traditional dental implants, corticotomy procedures by minimizing tissue damage, decreasing placed in stable zygomaticus bone. The original Brånemark side effects so that the patient experiences almost no postopera- zygoma implant protocol called for the placement of a single tive pain, allowing the suture to be removed several days postop- zygomatic implant in each zygoma with at least two conventional eratively, reducing the period with highest risk of infection to 3 implants placed in stable anterior maxillary bone, loaded in the postoperative days, rendering a surgical pack unnecessary, and conventional two-stage fashion. Materials and Methods: This case significantly decreasing swelling of the face. Materials and report presents the immediate loading procedure using four zygo- Methods: In the case of an 18-year-old male patient with Class II matic implants. Two zygomatic implants (Nobel Biocare) were division 1 malocclusion with a narrow maxillary arch, the patient placed in each zygomatic bone in such a manner that one zygo- wanted to correct a large overjet without tooth extraction. CBCT matic implant emerged in the anterior region of the remaining detected recessions of the labial alveolar bone of the lower alveolar ridge, while the other was placed more posteriorly. The incisors. The treatment plan was maxillary and mandibular Super apices of both implants converged toward the same reference, the Corticotomy Orthodontics: cutting the alveolar bone surface only jugale point, at the junction of the zygomatico-frontal and zygo- on the labial side without extracting teeth in order to expand and matico-temporal processes. On the day of implant placement, the move the maxillary arch distally. The treatment time was 14 interim removable prosthesis was converted into an implant- months. Results of cephalometric analysis showed that the tip of retained fixed prosthesis and was immediately loaded. The defini- the maxillary incisor moved 10 mm distally and the maxillary arch tive implant-supported screw-retained metal-ceramic fixed com- expanded 2 mm at the first molars. The mandibular incisor plete dentures will be fabricated after osseointegration is depressed 2 mm. Results: CBCT analysis of mandibular bone was achieved. Conclusion: This case report presents an alternate treat- done in a 0.125- to 0.500-mm-thick region of the mandibular left ment modality for patients with severely atrophic maxillary bone, central incisor in the sagittal section at the most inferior aspect of who are unable to tolerate complete maxillary dentures or whose the crestal bone, in the same location as the center of the root. previous attempts at conventional bone grafting and dental Comparison of pre- and posttreatment CBCT images showed the implant placement have failed. Acknowledgment: Zygomatic augmentation of labial alveolar bone at the mandibular incisors, implants and implant components were donated to Tufts where loss of labial bone existed at the opening of the flap. The University School of Dental Medicine by Nobel Biocare. root resorption of the mandibular left central incisor was about 1 mm and the length between the edge of the crown and the top No. 15 of the labial bone decreased 4 mm in the sagittal section, which Esthetic Surgical Crown Lengthening and Gingival supported the augmentation of the bone healing response. The Depigmentation: A Case Report. Y. Tsai, Y. Hsieh, C. Wang, J. postoperative structure of the labial alveolar bone was an Chen (Taipei, Taiwan) improvement over the preoperative structure; the cortical bone was thick and well-shaped 4 months into the retention stage and Introduction: Gingival health and appearance are essential com- kept the same bony structure for up to 1 year into the retention ponents of an attractive smile. Gingival hyperpigmentation is stage. Conclusion: Super Corticotomy Orthodontics is minimally mostly caused by the physiologic deposition of melanin. The invasive and very efficient for orthodontic patients. degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva does not present a No. 17 medical problem, complaints of “black gums” are common, par- A Multistage Procedure to Replace a Maxillary Central Incisor ticularly in patients having excessive gingival display (gummy with an Implant-Supported Single Tooth Restoration: A Case smile). Different treatment modalities have been reported for Report. G. Durstberger, E. Jiru, C. Ulm (Vienna, Austria) depigmentation of gingiva, such as bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery, and laser. This case Introduction: This clinical report shows the successful replace- shows cosmetic correction of “black gums” and “gummy smile.” ment of a maxillary central incisor by an implant-supported single Methods: Gingival depigmentation and surgical crown lengthen- tooth restoration in a multistage procedure. The left central ing procedure were performed for esthetic purposes. Results and incisor of a 30-year-old male was finally lost by root fracture. Conclusion: It seems that the depigmentation of melanin-hyper- During the previous 5 years, root canal treatment, apicoectomy, pigmented gingiva by the erbium, chromium:yttrium-scandium- and surgical treatment of a putative lateral periodontal cyst, gallium-garnet (Er,Cr:YSGG) laser and bur abrasion are both reli- which was found to be a periodontic-endodontic lesion, had been able and satisfactory procedures. Esthetic result was satisfactory performed on the tooth. Furthermore, the situation was compli- for the patient. No repigmentation was found during the follow- cated by the atypical involvement of the adjacent lateral incisor, up period. which showed a fistula and bone loss with increased probing depth distally and a buccal recession. During treatment, it was No. 16 discovered that all of these pathological conditions were caused Super Corticotomy Orthodontics: Case Report of Minimal by the inflammatory process of the left central incisor. Such a his- Intervention with a Cone Beam CT and a Microscope in the tory always results in an extensive defect of bone and soft tissue. Augmentation of Labial Alveolar Bone Without the Addition of Achieving a functionally and esthetically satisfying result proved Bony Material. S. Nakagawa (Kanagawa, Japan) to be a challenge not only for the clinician, but also for the patient. Materials and Methods: After the fractured left central Introduction: This report presents the results of the new cortico- incisor had been removed as atraumatically as possible, the tomy orthodontics (called Super Corticotomy Orthodontics) that patient was provided with a provisional resin-bonded fixed partial the author developed using cone beam computed tomography denture for the healing period. After 3 months, a CT scan was (CBCT) and a microscope. The CBCT (3DX multi-image micro CT, performed. As expected, the vertical as well as buccolingual J. Morita) is characterized by higher resolution (2.0l p/mm), very dimension of the alveolar bone was inadequate for placement of

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a dental implant. In the next surgical step, an autogenous block No. 19 graft, harvested from the left mandibular ramus, was augmented A Combined Investigate of Bone Microstructure Around to fit the defect. The onlay graft was fixed with a screw but not Nanotite Mini-Implants Placed in Humans. T. Traini, R. Celletti, covered by a membrane. Four months later, after healing of the M. Piattelli, G. Orsini, A. Scarano, S. Caputi (Chieti, Italy) bone, a dental implant was inserted in an ideal prosthetic position determined from a wax-up. After another 4 months of sub- Background: It has been shown in a human study that the rough- merged healing, the implant was uncovered and provided with a ness and chemistry of the implant surface with a deposition layer healing abutment. A connective tissue graft from the palate was of CaP nanocrystals are associated with early bone tissue integra- placed buccally to the implant and the left lateral incisor to tion and a significant increase of the BIC percentage (Orsini et al improve the soft tissue condition. Ten days later a provisional 2007). Osteocytes are the most abundant bone cells that are acrylic crown was inserted to enhance further improvement of the embedded in the matrix: They are the ideal location to form a soft tissue. Finally the implant was restored with a cemented sin- cellular syncytium able to sense the local environment and to gle tooth crown. To improve the esthetics of the maxillary ante- influence bone remodeling (Knothe Tate et al 2000). It has been rior teeth, veneers were suggested to the patient as an additional reported that osteocytes might also be more numerous in bone procedure. Conclusion: In this case it was possible to achieve a with higher turnover (Canè et al 1982; Power et al 2002). The good functional and esthetic result by a very complex, multidisci- bone tissue around dental implants needs a well-developed vas- plinary approach. However, the question arises of how to avoid cular bed in order to repair itself and maintain its functional struc- such extensive rehabilitation by choosing the right time to ture. Moreover, after implant placement the microstructured sur- remove compromised teeth. faces improve the de novo bone formation as a result of the early surface adhesion of noncollagenous proteins like osteopontin and No. 18 bone sialoprotein. Later on, calcium phosphate nucleation at the Assessment of Osstell and Periotest Systems in Measuring calcium binding sites on these proteins continues the process of Dental Implant Stability. F. Alshehri, S. Al-Jetaily, A. Al-Farraj osseointegration, which is completed by crystal growth and colla- (Riyadh, Saudi Arabia) gen production with mineralization (Davies 1998). Purpose: The aims of the present study were to measure the osteocyte density Purpose: To investigate the sensitivity and reliability of Osstell (OD) of de novo bone, to evaluate the three-dimensional bone system (Straumann) compared to Periotest system (Innova) in vascular canals of the bone around implants, and to analyze the measuring implant stability in four simulated conditions. These bone mineral density (BMD) of peri-implant bone. Materials and conditions resembled the different stages of healing or failure Methods: 15 custom-made 2 ϫ 10–mm implants were placed in around dental implants: direct implant-bone contact, fibrous tis- the posterior maxilla of 15 patients. Five specimens were used in sue-implant contact, hardening implant-bone interface, and dif- the present study; the implants were retrieved after 2 months. ferent horizontal levels of thread exposure. Materials and The retrieved specimens were fixed in a 10% buffered formalin Methods: Forty-nine dental implants were assigned to four solution dehydrated in a graded series of alcohol and embedded groups and were placed in the center of acrylic cubes (15 ;180; in LR white resin. In order to evaluate both the osteocyte density 15 ϫ 20 mm). Group 1: Implants were placed in direct contact and the bone mineral density, we used a brightfield microscope with acrylic resin. Group 2: Implants were placed in the presence equipped with a circularly polarized light (CPL), a confocal scan- of 0.05-mm-thick impression material as a soft interface. Group 3: ning laser microscope (CSLM), and a scanning electron micro- Implants were placed in the presence of a 0.05-mm-thick fresh scope (SEM) with backscattered electron (BSE). Results: The OD mix of acrylic resin as a hardening interface. Group 4: Implants (mean ± SD) of de novo bone contacting the implant surface was were assigned into four subgroups and were placed in direct con- 575.6 ± 34.2 mm-2, while the OD in the old bone was 437.3 ± tact with the acrylic cube while the implant threads were exposed 24.1 mm-2. The vessels network appeared as an intricate mesh of at four horizontal levels: 0, 2, 4, and 6 mm. The implants’ stability small vessels running circularly around the implant body, mainly was measured using Osstell and Periotest systems. Results: The in the inter-threads areas, where most of the de novo bone was mean Periotest value ± SD for the direct acrylic contact group observed. Around vascular bone canals many osteocytes were was 3.52 ± 1.39 PTV and 5 ± 0.58 for the soft interface group. noted to form a very intricate network with their projections that The mean Osstell measurement ± SD was 70.43 ± 0.0 ISQ for the resulted in direct attachment to the bone side of the vascular first group and 53.95 ± 0.24 ISQ for the second group. A statisti- wall. The extension of the BMDlow for de novo bone contacting cally significant difference was found between the two groups (P the implant surface was 662.4 ± 7.3 x103 µm, while the area of <.01). In Group 3, a strong correlation was found between Osstell the BMDhigh for old bone was 379.6 ± 3.3 x103 µm. Conclusion: measurements and the changes in the hardening interface during The slightly higher number of osteocytes and the presence of a the acrylic resin polymerization (r = 0.986). In Group 4, the mean well-developed vessel network with an extensive area of bone PTV ± SD was 3.52+/-1.39, 1.14+/-0.84, 1.28+/-0.35 and 4.33+/- with a low mineral density indicate an active structuring process 0.14 PTV, while the mean ISQ was 70.43 ± 0.0, 64.14 ± 0.24, of the bone (osteoconduction) around implants treated with a 59.47 ± 0.61 and 52.14 ± 0.97 ISQ for the four subgroups, deposition of a nanocrystal layer of CaP. Acknowledgment: respectively. A statistically significant difference was found Experimental implants were provided by BIOMET/3i. between the four subgroups (P < .01). The level of horizontal fix- ture exposure was strongly correlated with PTVs (r = 0.967) and No. 20 strongly negatively correlated with ISQ (r = –0.946). Conclusions: Tooth Extraction, Site Augmentation, and Implant-Supported Both systems proved to be sensitive in measuring implant stabil- Restoration in a Single Procedure. A. Ferrara, S. Lumetti, E. ity in hard and soft interfaces. Osstell also proved to be more Manfredi, C. Galli, M. Bonanini, G. Macaluso (Milan, Italy and sensitive in detecting any minor changes in the interface around Parma, Italy) the dental implant. The reliability of the Osstell system increases as the implant stability increases, while the reliability of the Introduction: Implant-supported prosthesis original protocols are Periotest system increases as the implant stability decreases. long. Extraction, bone regeneration when necessary, implant Acknowledgment: This research was funded by King Saud insertion, and second phase surgery for healing screw positioning University Research Center and Straumann Institute. are performed during different surgeries, taking up to 18 months from diagnosis to final prosthesis. For a failing single tooth, short- ened protocols have been proposed. Most of the protocols are either for immediate implant placement at extraction or immediate nonfunctional load at implant placement. A few studies also investigated the combination of these two techniques in one day. Purpose: The aim of this case series is to present a protocol combining tooth extraction, site augmentation, implant insertion, and

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nonfunctional load in a single procedure. Methods: Eleven con- Conclusion: The combined use of microarray technology with secutive patients (six female and five male; age range 21 to 69 BADGE provided a set of candidate genes that may serve as years) were treated. Seven maxillary premolars, three mandibular novel therapeutic intervention points as well as improved diag- premolars and a primary canine were scheduled for extraction nostic and screening procedures for high-risk individuals. due to vertical fracture (seven) or periodontitis (four). All the patients showed bone defects on the buccal side of the tooth. A No. 22 buccal flap was elevated, the tooth was extracted with minimal The Importance of Periostin in the Function of the Periodontal trauma, and the defect was carefully debrided. The implant site Ligament. H. Rios, G. Avila, W. Giannobile (Ann Arbor, Michigan) was prepared with drills, and a root form implant (Xive, Friadent) was inserted (3.8- or 4.5-mm diameter, 13- to 18-mm length). Introduction: The periodontium is subjected to physical forces dur- Residual labial bone was not involved in site preparation, and the ing function. The ability of the periodontal ligament (PDL) to implant was placed slightly more lingual or palatal than the absorb and distribute these forces greatly influences the periodon- extracted tooth. The implant head was positioned 2 to 3 mm api- tal homeostasis. This adaptive response may be determined by the cal to the interproximal bone level, and the implant diameter was orchestration of key molecules that control the integrity of the PDL chosen to minimize the gap with alveolar walls. The buccal bone during occlusal function. periostin, a 90-kDa extracellular matrix defect was filled with autogenous bone chips and deproteinized protein primarily expressed in PDL, is likely to be one of these key bovine bone (Bio-Oss, Osteohealth). The graft was covered with a molecules since the cementum, alveolar bone, and PDL of collagen membrane (Bio-Gide, Osteohealth), and the flap was periostin-null mice dramatically deteriorate after the teeth erupt. sutured (Gore-Tex, W. L. Gore) with no tension. A provisional Purpose: The purpose of this study was to determine the role of abutment (Frialit II Protect, Friadent) was screwed on the implant periostin in the periodontium. Materials and Methods: The and a provisional resin crown immediately adapted to nonfunc- mandibular and maxillary molar and incisor periodontium from tional loading. All procedures were performed in the same day. periostin-null mice were characterized and compared to wild types Oral antibiotics (amoxicillin, 1g twice a day) and 0.12% chlorhexi- using histology, immunohistochemistry, scanning electron dine rinses twice a day were prescribed for 6 days. After 8 months microscopy, transmission electron microscopy, and radiographs. A a porcelain-fused-to-metal crown was cemented to a custom- model of hypofunction was created by taking one mandibular made titanium abutment. Results: All the implants showed good incisor of the periostin-null mice out of occlusion by weekly trim- primary stability and an uneventful healing phase. At the 2-year ming of the incisal edge starting at 10 days. The contralateral follow-up consultation, no pain was present and implants were incisor was used as an internal control. The effect was evaluated by stable with no sign of inflammation. Radiographic studies showed histologic and radiographic comparison. The strain effect on no radiolucency around the implants, and the marginal bone loss periostin expression was evaluated using a murine PDL cell line. compared to presurgery radiographs was less than 1.5 mm. Soft These fibroblasts were cultured in flexible-bottomed culture plates, tissue contraction was minimal when compared to baseline. and cyclicly stretched at 6 cycles/min at each of three levels of Conclusion: Immediate post-extraction implant insertion, nonfunc- elongation (1%, 14%, 20%) for 48 hours. Real-time RT-PCR was tionally loaded, could be considered a feasible procedure to used to quantify mRNA levels of periostin. In addition, TGF-␤ PAM reduce treatment duration and patient discomfort even in cases of neutralizing antibodies were added to the cultures, and periostin guided bone regeneration (GBR) procedures. The significance of and TGF- ‚ levels were measured under the same conditions. the present case series is to offer a proof of concept of this proto- Results: Subsequent to the complete eruption of the molars and col. Further controlled studies are needed to address the validity incisors, severe periodontal and enamel defects occurred in the and clinical significance of the present technique. periostin-null mice. However, the absence of masticatory forces in the periostin-null mice hypofunction model resulted in ameliora- No. 21 tion of the periodontal phenotype and in normal incisor formation. Gene Expression Profile in Refractory Periodontitis Patients. The most significant changes on periostin expression occur under D. Kim (Cambridge, Massachusetts) mechanical tensional stress of medium magnitude (14%). Periostin increased by 0.9-fold at 6 hours and went up to 9.2-fold at 48 Introduction: There are no specific bacterial profiles or diagnostic hours. To determine whether this was a direct or indirect response tests capable of identifying refractory periodontitis patients to mechanical stress, we measured the level of TGF-‚, which is before a treatment regimen is initiated. Therefore, in this high-risk known to be upregulated by mechanical loading. TGF-␤ increased cohort of patients who do not respond appropriately, host factors by 6.9-fold at 6 hours, and decreased to 3.6-fold at 48 hours. Both that might be partly under genetic control may play a crucial role gene responses to mechanical stress were completely blocked by in their susceptibility. Specifically, we tested the hypothesis that the addition of 2.5 ng/mL of neutralizing antibodies. Conclusion: patients with refractory periodontitis have multiple upregulated Collectively, our data supports our hypothesis that periostin is and/or downregulated genes that might influence clinical risk. essential for the integrity of the periodontium in response to Methods: Oral subepithelial connective tissues were harvested occlusal load. The data generated has major implications for our aseptically from seven refractory periodontitis and seven peri- understanding of periodontal biology. These studies strongly sug- odontally well-maintained patients. An RNA isolation kit was uti- gest the existence of novel pathways that may determine peri- lized to isolate total RNA from tissue samples that had been stabi- odontitis susceptibility that could be targeted in the treatment of lized in the RNA-stabilizing reagent. The isolated total RNA was metabolic periodontal diseases. Acknowledgment: This work was then subjected to gene expression profiling using the microarray supported by NIH/NIDCR T32DE07294. to measure gene expression levels. The retrieved data was analyzed with a “BADGE” (Bayesian Analysis of Differential Gene No. 23 Expression) program for the differential analysis of gene expres- Comparative Study Using Two Different Composite Bone Graft sion microarray experiments. In addition, real-time PCR analysis Mixtures for Sinus Augmentation. P. Galindo-Moreno, G. Avila, was performed on selected samples in order to confirm the H. Rios, C. Ferre-Lopez, I. Moreno-Riestra, A. Fernández Jimenez, microarray data’s gene expression patterns. Results: A total of 68 H.Wang (Granada, Spain and Ann Arbor, Michigan) upregulated and 6 downregulated genes were identified that were differentially expressed by at least twofold of the 22,283 Introduction: Bone availability is essential for a successful osseoin- genes studied. The selected model provided a 93% intrinsic vali- tegrated implant treatment. Performance of implant surgery tech- dation along with a 93% extrinsic validation. In order to validate nique in the posterior maxilla often poses a challenge to the clini- the microarray data, five upregulated genes (LTF, MMP-1, MMP- cian given insufficient amount of remaining bone after tooth loss. 3, IFI-15, MGC5566) and two downregulated genes (KRT2A and Sinus augmentation is a highly suitable therapeutic option to over- DSC-1) were randomly selected for further analysis by real-time come this problem. To perform sinus augmentation, a large variety PCR. The relative RNA expression level of these genes measured of biomaterials have been described, obtaining good results in the by real-time PCR was similar to those measured by microarrays. majority of the reports. Purpose: To compare two different grafting

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materials used for sinus augmentation in terms of clinical out- No. 25 comes and biologic benefits. Materials and Methods: Five Use of Astra Tech Osteotomes and Bone-Trap for Volume patients who underwent a bilateral sinus lift technique for the Collection in Dental Implantology: A Case Report. M. Pavão, R. placement of implants in the maxillary area were recruited for this Cruz, P. Paúl (Madrid, Spain and Porto, Portugal) study. Two different graft materials were used per patient in each sinus augmentation: the cortical bone overlying the sinus mem- Bone grafting is often needed to augment the dentoalveolar brane as a graft, collected with a Safescraper (BIOMET/3i), in com- ridge or the maxillary sinus in cases where oral implants are to be bination with bovine bone (Bio-Oss, Osteohealth) and the same placed in the proper three-dimensional restorative-driven posi- overlying autologous bone in combination with synthetic tion. Autogenous bone grafts are often the preferred choice and resorbable bone substitute (Novabone). Bone core biopsy sam- can be used either alone or combined with xenografts or alloplas- ples of the augmented site were taken with a trephine for histo- tic materials. Combining an alloplastic material with autogenous logical analysis 6 months later, at the time of implant placement. bone can decrease the amount of alloplastic material that would Six months after implant placement, fixed partial dentures (FPD) have been used in order to increase the majority of the graft. were fabricated to load the implants. Peri-implant bone was evalu- When multiple sites are planned, and only a few of them need ated 12 months after loading. A comparative histomorphometric augmentation, sufficient bone can often be obtained using a analysis was made using the software Image J, and statistical anal- bone collector. Little research has been done on the use of these ysis was performed. Results: After a 6-month period of healing, devices. The use of bone collectors provides a more osteogenic the histologic study was made, and it was observed that compos- bone graft, spares time, and also reduces expenses associated ite grafts presented a high biocompatibility, but demonstrated lit- with alloplastic materials. Materials and Methods: Measurements tle resorption rate in the case of Bio-Oss. On the other hand, the of implant osteotomy bone volumes harvested from site prepara- study of Novabone samples revealed that the resorption rate was tions with a bone collector (BoneTrap, Astra Tech Systems) faster, with some particles of this biomaterial included in new nor- enabled the surgeon to predict in advance if additional graft mal bone with active osteoblasts producing osteoid matrix. In all material would be needed to fill in the defect. The technique was the cases, implants placed after sinus augmentation are functional employed so that, during site preparation, the bone could be re- after a 12-month period of loading. No bone loss associated with used for grafting procedures as described. With the use of the grafts was observed either radiographically or clinically. BoneTrap, auto-donation allowed for elimination of immunologi- Conclusions: Sinus augmentation technique, using a composite cal reactions and lowered the risk of transferring infections to graft, is a predictable technique with adequate implant survival almost zero. Results: The simple procedure provided the perfect outcomes more than 12 months after loading. Disclaimer: The bone material for handling localized defects through spot collec- authors don’t have any financial interests, either directly or indi- tion of bone particles that would have otherwise been discarded rectly, in the products listed in the study. down the suction line. BoneTrap, used together with the osteotome technique, allows for the keeping of a safe distance No. 24 from the maxillary sinus floor. The Use of Regenaform Allograft in Vertical Ridge Augmentation with e-PTFE Membranes. F. Fontana (Milan, Italy) No. 26 Implant Placed in Fresh Extraction Sites Presenting Radiographic Purpose: To compare clinically and histologically the allograft Evidence of Endodontic and Periodontal Lesions: A 5-Year Regenaform to the autogenous bone graft in the vertical ridge Prospective Clinical Study. M. Bibeau (Prescott, Arizona) augmentation technique using titanium reinforced e-PTFE membranes. Materials and Methods: Five female patients (10 surgical Introduction: Placing implants in fresh extraction sites increases sites) requiring vertical ridge augmentation bilaterally to allow the long-term esthetic outcome by minimizing bone resorption implant insertion were included in the study. All patients were and soft tissue recession. Infection in tooth extraction sites has treated with a split-mouth design approach: at first surgery each traditionally been considered a major indicator for postpone- side was randomly assigned to the test group consisting of tita- ment of implant placement until the infection is resolved by nium reinforced e-PTFE membrane and Regenaform (Exactech) or extraction and a prolonged healing period. Purpose: The goal of to the control group consisting of titanium reinforced e-PTFE this study was to evaluate the survival rate of implants placed in membrane and autogenous bone graft. Each group included five infected extraction sites relative to implants placed in healthy surgical sites. Twenty-five Brånemark implants were inserted (13 sites. A total of 684 root form dental implants were placed in vari- test group, 12 control group). The DSB (distance between the top ous locations of the maxilla and mandible according to conven- of the screw head and the first visible bone-screw contact) and the tional protocol of implant placement. Materials and Methods: DIB (distance between the top of implant head shoulder and the One hundred thirty-five of the implants were placed in extraction first visible bone-implant contact) measurements were taken. Nine sites of teeth exhibiting radiographic signs of periodontal or biopsies from the regenerated area were evaluated histologically endodontic infection. Two hundred twenty-eight implants were and histomorphometrically. Results: Clinical results: in the test placed in extraction sites exhibiting no radiographic signs of group no membrane was exposed. The mean bone regeneration infection. Three hundred twenty-one implants were placed in vari- (DIB) was 4.70 mm (SD ± 0.48 mm). All 13 implants appeared clini- ous healthy edentulous areas. Standardized intraoral radiographs cally stable. In the control group one membrane was exposed were taken of all 684 root-form implants at 1-, 3-, and 5-year after 2 months. The mean crestal bone regeneration was 4.10 mm intervals. Evaluation of the marginal bone levels and mean bone (SD ± 0.88 mm). All 12 implants were stable at the abutment con- loss were registered. Results: In the group of implants placed in nection. Histologic results: vertical bone regeneration was evident infected sites, one implant was lost, resulting in a 99.3 % survival both in the test group and in the control group since all the sam- rate. A mean bone loss of 0.6 (SD 1.2) was registered. In the ples demonstrated trabecular bone with different degrees of mat- group of implants placed in what appeared to be healthy extrac- uration and mineralization in the regenerated area. Conclusion: tion sites, seven implants were lost, resulting in a 97% survival The findings from the present clinical and histological study sup- rate. A mean bone loss of 0.7 (SD 1.2 ) was registered at the port the use of Regenaform as a bone substitute for vertical ridge same intervals. In the group of implants placed in a healthy eden- augmentation of atrophic ridges by means of guided bone regen- tulous ridge, 12 implants were lost, resulting in a 96.3% survival eration (GBR) techniques. Nevertheless, long-term clinical studies rate. A mean bone loss of 0.9 (SD 1.4 ) was registered at the are needed to confirm the positive effects of Regenaform in same intervals. Conclusion: The results of the present study sug- enhancing the lasting stability of the vertically augmented bone. gest that implants placed in infected extraction sites integrate with a high survival rate and maintain excellent bone levels after extended periods of time.

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No. 27 treat severely deficient alveolar ridges and to determine the value Improvement of Facial Profile after Ridge Augmentation of of a resorbable membrane to the efficacy of the procedure. Anterior Maxilla. D. Haam, G. Favero, W. Chang, S. Cho, S. Materials and Methods: Six foxhounds received bilateral extrac- Froum, N. Elian, D. Tarnow (New York, New York) tion of four mandibular premolars, and a vertical alveolar ridge defect, 1 cm ϫ 3 cm, was created, simulating significant atrophy Introduction: Traditionally, fixed partial dentures have long been that would not heal spontaneously. Three months later the artifi- the treatment of choice in the anterior maxilla for partially edentu- cially created defects were grafted. Three cohorts were included; lous patients. However, many patients with severe ridge deficien- Group A: Block and membrane, Group B: Block and PDGF, and cies who were brought back to function with this mode of treat- Group C: Block, PDGF, and membrane. Sacrifice occurred at 4 ment were not satisfied because of the depressed facial profile months. Results: Histologic examination of Group B revealed a following final restoration. To improve facial profile, several treat- large amount of new bone formation at the coronal portion of the ment options have been utilized, including removable partial den- regenerated tissue facing the periosteum and in continuity with tures, orthodontic treatment with or without orthognathic surgery, the native bone. A high rate of bone-to-implant contact was visi- and plastic surgery. Currently, ridge augmentation procedures ble over the top of the cover screw. Bone formed from the have become more widely used to regenerate atrophic ridges and periphery of the block inwards, indicating that cell recruitment allow the replacement of missing teeth with implants. Some occurred from both periosteal and medullary sources. Discussion: patients show significant improvement in facial profile after ridge Unlike traditional guided bone regeneration (GBR) procedures, augmentation procedures with subsequent implant placement. where placement of a barrier membrane preferentially drives Purpose: The aim of this study was to evaluate the improvement of bone formation and prevents soft tissue ingrowth, the collagen facial profile after ridge augmentation and implant placement in barrier appears to block cellular penetration into the graft, critical the maxillary anterior area. Materials and Methods: Ten consecu- for growth factor–mediated bone regeneration. With direct access tively treated cases with ridge augmentation in the anterior maxil- to the periosteum and its rich supply of osteogenic cells, there is lary area were included to evaluate the improvement of facial pro- strong evidence that PDGF exerts a potent chemotactic effect. file. Comparison of clinical photos and cephalometric analysis of Osteoblasts and precursor cells migrate from the periosteum and both soft and hard tissues were performed to measure the differ- medullary space to the matrix. PDGF additionally appears to ences pre- and postsurgery. Results: In this study, the subjects dis- accelerate bone formation and remodelling. Conclusion: The played an average preoperative nasolabial angle of 110 degrees. results indicate that PDGF and xenogenic matrix are capable of Following treatment, the angle was decreased to an average of regenerating bone in large, chronic osseous defects, that the new 104 degrees as measured by cephalometric analysis of both soft bone forms in intimate contact with titanium implants, and that and hard tissues. Conclusion: Ridge augmentation procedures may blocking the periosteum reduces the effectiveness of this growth- be treatment options for patients who are partially edentulous in factor-mediated response. the anterior maxilla and who need improvement in facial profile. No. 30 No. 28 Computer-Aided Laser-Assisted Minimally Invasive Immediate Soft Tissue Dimensions in Resorbed Maxillary Alveolar Ridges Denture Loading: Diagnosis to Delivery. D. Digiallorenzo Assessed by CAT-Scan Images. O. Ortiz, C. Hery, D. Holmes, S. (Collegeville, Pennsylvania) Cho, S. Froum, N. Elian, D. Tarnow (New York, New York) Introduction: A 4-year private practice retrospective analysis of 49 Introduction: The quality and dimensions of peri-implant soft tis- Xive and Ankylos immediate load overdenture implant restorations sues are the basis of an ideal esthetic outcome in implant-sup- (Friadent) was done in order to evaluate the implants’ rate of sur- ported restorations. Deformed edentulous ridges may compro- vival. Materials and Methods: According to diagnostic protocol, mise this ideal situation. Moreover, they can compromise implant occlusion, bone quality and quantity, soft tissue quality and quan- placement and implant survival. Several published reports classify tity, periodontal diagnosis, existing denture esthetics, phonetics, ridge defects to help plan the treatment regimen for clinical cor- vertical dimension, wear and general medical condition of the rection. However, to date, no classification system includes soft tis- patient, and risk factors were evaluated. The patient population sue dimensions in a ridge defect area, although soft tissue condi- was healthy with one smoker. Patients ranged in age from 35-85 tion is a critical determinant for esthetic implant restorations. years. For edentulous patients, a CT Scan (SimPlant, Materialise) Purpose: The purpose of this study was to measure the dimensions with a barium stent was used for optimal implant positioning, of soft tissue in areas of alveolar ridge defects utilizing computer- nerve identification, and minimally invasive surgical technique. ized axial tomography (CAT) and to establish a more precise classi- Possible access was made utilizing a Diode laser in edentulous fication system of alveolar ridge defects. Materials and Methods: cases, and all intra-sulcular incisions were made with the diode Fifty-five patients were selected from New York University College laser with no verticals. All implant surfaces were rough-surfaced of Dentistry’s Department of Periodontology and Implant Xive and Ankylos implants. Sixteen implants were placed into Dentistry. These patients presented alveolar ridge resorption in the immediate extraction sockets due to advanced periodontal dis- maxillary anterior area. After ideal waxup reconstruction, buccal ease and root surface caries. All sockets with a micro-gap greater and palatal extended radiographic templates were fabricated, and than 1.5 mm were grafted with a combination of autogenous, the patients were sent for CAT scan explorations. Coronal, buccal, MFDBA (Puros, Zimmer), Pepgen 15 (Dentsply), or Osteograft and lingual measurements of the soft tissue thickness were per- (OsteoMed) material. All sockets were treated with 1mg minocy- formed on these defects utilizing CAT scan–based software. cline and a Peridex (Procter & Gamble) and iodine flush. Thirty-two Results: The results obtained in this study showed that the average implants (12 maxillary and 20 mandibular) were placed into the soft tissue thickness in edentulous ridge defects was: 3.1 mm coro- edentulous ridge. Seventeen implants were maxillary implants. nally, 2.8 mm buccally, and 4.1 mm lingually. Conclusion: Soft tis- Two implants were placed into sinus-grafted bone allograft utiliz- sue dimensions should be considered in ridge classification sys- ing mineralized freeze dried bone (Puros). Thirty-two implants were tems in order to facilitate ideal implant placement. mandibular implants. The range in implant diameter was 3.5, 3.8, and 4.5 mm; range in length was 8.5, 9.5, 10, 11, 13, 15, and 17 No. 29 mm. Opposing occlusion was either complete denture or natural Bone Regeneration Mediated via a Periosteal Mechanism with dentition. Either Locator attachments (Zimmer) or SynCone Platelet-Derived Growth Factor. I. Rocchietta, D. Kim, J. Fiorellini, (Friadent) abutments were used, depending on the interocclusal M. Simion (Milan, Italy) clearance. All implants were torqued to at least 24 Ncm at the time of surgery. All implants were parallel within 5 degrees. Hard relines Purpose: The aims of this study were to evaluate the outcome of were completed by a chairside procedure using either the vertical ridge augmentation in a standardized dog model by com- SynCone technique or the Locator technique. All complete den- bining rhPDGF-BB with a deproteinized cancellous bone block to ture occlusions were adjusted to ensure bilateral group function.

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Patients were instructed to leave the dentures in place for 2 weeks without removing them and to maintain a soft diet. Amoxicillan 500 mg was prescribed 1 day prior to surgery and for 7 postoperative days. One Motrin 800 was taken prior to the visit and every 6 hours afterward as needed. One 9.5-mm implant was removed in the mandibular right first molar area after 8 weeks. De-integration occurred as a result of resorption of the lingual bony housing. It was replaced immediately in an anterior position and loaded immediately. This was mainly due to operator error in positioning in relation to the lingual bony housing. The survival rate of the implants, studied over a 4-year observation period, is 100% to date. Conclusions: With specific case selection and precise planning, immediate denture loading can predictably ensure a high degree of success in restoring form and function to a debilitated denture-wearing population if the following specific criteria are followed: (1) Detoxification of the implant site in immediate sites (2) Primary stability (macro-mechanical retention) 24 Ncm and optimal micromechanical retention (surface processes) (3) Limiting of micromechanical motion at the bone-implant interface through splinting (4) Creating a therapeutic balanced occlusion in order not to overload one segment (5) Preventing epithelial healing at the bone-implant interface by grafting the micro-gap when it exceeds 1.5 mm (6) Preventing trauma during healing by maintain- ing a soft diet and limiting insertion and removal. The benefits of this therapy are prevention of hard and soft tissue resorption, increased chewing efficiency, increased force transmission during the chewing cycle, and improved absorption of vital nutrients due to better digestion, mastication, and food choices. Finally, this therapy reduces embarrassment resulting from ill-fitting dentures, a psychological benefit important to many patients. By providing this therapy in one visit, practitioners can enhance patient satisfac- tion, particularly for elderly patients who may prefer to complete their therapy in as little time as possible.

No. 31 Bone Spreading and Standardized Dilatation of Horizontally Resorbed Bone with Simultaneous Implant Placement: Technical Considerations and Case Reports. R.S. Nishioka, A.N. Kojima, F.A. Souza (São José dos Campos, Brazil)

Introduction and Discussion: Rehabilitation of the edentulous maxilla has been a challenge for oral surgeons. The spreading system is an alternative technique to Summer’s osteotome technique. The main advantage of the crest expansion technique is a less invasive procedure; the facial wall expands after the modular bone is compressed against the cortical wall. The technique improves the density of the maxillary bone, which allows greater initial stability of implants. Specific screw instruments—a “spreader” in particular—achieve a controlled and standardized dilation of horizontal bone. One year after more than 25 sites were treated with this procedure, no failures or significant complications were observed. The use of spreaders to enhance dental implant sites is a highly predictable procedure. This technique avoids discomfort for the patient. As an alternative to standard drilling, spreaders are used to gradually expand and compress cancellous bone, improving localized bone density and resulting in optimized primary stability. Adequate primary stabilization of maxillary implants at the time of installation is considered one of the primary reasons for osseointegration. As an alternative to standard drilling, spreaders are used to gradually expand and compress cancellous bone, improving localized bone density and resulting in optimized primary stability. Adequate primary stabilization of maxillary implants at the time of placement is considered one the primary factors in osseointegration. We preferred using the spreaders throughout the entire procedure because hand instrumentation facilitated better tactile sensitivity, more precise control, and less heat generation. Purpose and Conclusion: It is important that the clinician be well-versed in these various treatment modalities. The protocol outlined in this study was developed to standardize the planning approach for the treatment of resorbed maxillae to achieve predictable results. However, further clinical studies are needed to confirm these results.

Volume 27, Number 5, 2007