The International Journal of Periodontics & Restorative Dentistry

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Use of a Novel Implant with an Inverted Body-Shift and Prosthetic Angle Correction Design for Immediate Tooth Replacement in the Esthetic Zone: A Clinical Case Series

Stephen J. Chu, DMD, MSD, CDT1 Although immediate tooth replace- Barry P. Levin, DMD2 ment therapy (ITRT) has become a Nicholas Egbert, DDS, MDS3 viable treatment, esthetic outcomes Hanae Saito, DDS, MS4 remain a challenge in the maxil- 5 Myron Nevins, DDS lary anterior region. What is now biologically evident is the need for protection of the facial plate sur- A clinical case series of three patients is presented using a novel implant design rounding the implant for long-term to not only address primary stability but also to prevent damage to the labial maintenance and sustainability.1–4 bone plate and improve the interdental space for papillae preservation with Notwithstanding, achieving pri- immediate tooth replacement therapy. This unique implant design features an mary implant stability in extraction apicocoronal inverted body-shift in diameter (wide to narrow), shape (tapered to cylindrical), thread depth (deep to shallow), and thread pattern (V-shaped to sockets that frequently are compro- square) to achieve uncompromised primary stability and esthetics, particularly mised with limited bone is critical for in extraction sockets, in a singular body form. In addition, the implant possesses initial implant survival and, subse- a prosthetic angle correction within the implant body to facilitate screw- quently, its success. Tapered, wide- retention of the restoration and avoid the risk of apical socket perforation. Int diameter implants are commonly J Periodontics Restorative Dent 2021;41:195–204. doi: 10.11607/prd.5401 used to achieve high levels of stability in immediate extraction sites. This design inherently minimizes the distance between, and the facial proximity to, the implant platform and the extraction socket’s thin bony wall (Fig 1). Narrow-diameter implants provide greater space for crestal bone augmentation but lack 1Ashman Department of Periodontology and Implant Dentistry, Department of the level of primary stability needed Prosthodontics, New York University College of Dentistry, New York, New York; Private to support an immediate provisional Practice, New York, New York, USA. restoration or final restoration.5,6 2 Department of Periodontology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania; Private Practice, Jenkintown, Pennsylvania, USA. A macro-hybrid implant design 3Roseman University Dental School, South Jordan, Utah, USA; Private Practice, was created to provide common Salt Lake City, Utah, USA. ground between wider, tapered 4 Division of Periodontics, University of Maryland School of Dentistry, Baltimore, implants, which increase primary Maryland, USA. 5Department of Oral Medicine, Infection, and Immunity, Division of Periodontology, stability, and narrower implants, Harvard School of Dental Medicine, Boston, Massachusetts, USA. which provide greater coronal gap space.7–12 In a preclinical study, the Correspondence to: Dr Stephen J. Chu, 150 East 58th St, New York, NY 10155, USA. Email: [email protected] inverted implant with a body-shift design (INV) with a narrow cylin- Submitted August 25, 2020; accepted August 28, 2020. ©2021 by Quintessence Publishing Co Inc. drical coronal portion 40% of the

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implant distance for papillae maintenance while facilitating prosthetic screw-retention of provisional and definitive restorations.

Clinical Case Reports

Case 1

A 62-year-old Asian woman presented with vertical crown and root fracture of the maxillary left central incisor (Fig 2). Prior dental history of the incisor included a b progressive pulp atrophy due to a Fig 1 CBCT scans of (a) a tapered conventional implant and (b) an inverted body-shift mild traumatic injury, treated with (INV) implant placed into extraction sockets at 1 year of healing. The reformed labial plate endodontic therapy and nonvital dimension on the tapered implant is less than that of the INV implant. internal bleaching. The patient was given pretreatment antibiotics (2 g amoxicillin) 1 hour before treatment. length of the implant body allowed without compromising esthetics.13,14 The tooth was removed atraumati- for extremely high primary stability An added benefit of SAC is that the cally without flap elevation, and (mean: 90 Ncm) but also a signifi- implant-abutment interface or plat- thorough socket debridement was cant crestal gap distance from the form is variable in dimension, with performed. The incisal-edge posi- surrounding socket walls, which pre- the greatest amount at the direct tion was used as a point of reference dictably achieved osseointegration facial aspect. This design is known when creating a precise osteotomy without internal grafting.7 Clinically, as variable platform switching (VPS). at the apicopalatal aspect of the this gap space allows the addition of Strategically, combining properties socket. The osteotomy was sized hard tissue biomaterial to augment of different implant concepts into a to receive an INV implant that was the labial plate at the time of ITRT. singular body—thus creating a hy- 13.0 mm long and 4.5 mm in di- Further, the reduced coronal diam- brid implant with a wider, tapered ameter at the apical portion (which eter and cylindrical shape provides apical aspect and a narrower, cy- comprised roughly 50% of the to- unobstructed seating of provisional lindrical coronal aspect—with SAC tal implant length), with a 3.5-mm restorative components. This im- and VPS affords clinicians both short coronal cylindrical portion (compris- plant has a subcrestal (prosthetic) and potentially long-term advan- ing about 40% of the total implant angle correction (SAC) feature that tages that have not been seen with length), as well as SAC and VPS fea- permits implant placement along other implant designs. tures (INVERTA Co-Axis, Southern the long axis of the adjacent teeth The present clinical case re- Implants) to ensure a screw-retained coincident with the incisal edge po- ports demonstrate multiple benefits restoration. This co-axial design al- sition. This enables the implant to of this INV design in ITRT, including lows the surgeon to make the oste- engage with an optimal amount of high levels of primary stability, en- otomy behind the apex of the tooth apicopalatal bone for stability while hancement of the thin facial bone root, thus engaging the maximum consistently delivering palatal ac- plate demonstrated on CBCT ra- amount of available apicopalatal cess for screw-retained restorations, diographs, and increased tooth-to- bone and avoiding apical perfora-

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a b c Fig 2 Case 1. (a) Facial view of the maxillary left central incisor with a vertical crown, root fracture, and a periodontal abscess at the free gingival margin. The sounding depth was 4.5 mm to the bone crest, indicative of 1.5 mm of bone loss. (b) Periapical and (c) CBCT radiographs show a subosseous root fracture on both the facial and palatal aspects.

tion of the labial bone plate (Fig 3).15 Because the bone quality was soft (D316), the osteotomy site was underprepared by 0.75 mm, and an insertion torque value of 80 Ncm was achieved at placement. Prior to grafting the gap, a preformed gingival former (iShell, Vulcan Custom Dental) was used to help fabricate a screw-retained acrylic provisional restoration attached to polyether ether keytone (PEEK) with a full labial restorative contour to support the peri-implant soft tissues. A healing abutment was used to protect Fig 3 Case 1. After flapless tooth removal, thorough socket debridement, and the oste- the screw access hole and to allow otomy, the implant mount’s depth marker denotes 3.0 mm from the free gingival margin a small-particle mineralized cancel- and an orientation groove that should be position facially once the implant is correctly seated. This co-axial design allows the surgeon to make the osteotomy behind the apex of lous allograft (MinerOss, BioHori- the tooth root, thus avoiding perforation of the labial bone plate. The prosthetic screw ac- zons) to be placed in the bone and cess should face the direct palatal aspect of the carrier, then the mount can be unscrewed in soft tissue zones (dual-zone thera- and removed. The implant was delivered with an insertion torque value of 80 Ncm. peutic concept; Fig 4).17 Excess biomaterial was removed following reinsertion of the position and during lateral excursion to heal for a full 5 months prior provisional restoration to contain movements. The patient continued to first removal of the provisional and protect the graft material during the antibiotic regiment for 1 week restoration and final impression- the initial healing phase. The restora- posttreatment and was instructed making (Figs 5 and 6). A metal- tion was reevaluated for nonocclusal to not brush the surgical site for 5 ceramic screw-retained implant contact in the maximum intercuspal to 7 days. The implant was allowed crown was fabricated and delivered

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Fig 4 Case 1. After the provisional restoration is made, a healing Fig 5 Case 1. The provisional restoration was allowed to heal for abutment is placed on the implant to allow grafting and to prevent 5 months prior to first disconnection and impression-making. Note biomaterial from blocking the screw access channel. Graft material the resolved periodontal abscess and the preservation of the ridge is placed circumferentially around the healing abutment. contour, shape, and papillae.

Fig 6 Case 1. Healthy peri-implant soft tissues can be seen at Fig 7 Case 1. The final metal-ceramic screw-retained restoration crown delivery. The ridge dimension was preserved, and the peri- intraorally with satisfactory esthetic integration. The Pink Esthetic implant soft tissues were enhanced using the dual-zone grafting Score was 13, as there was a slight change in ridge shape due to technique. the preoperative infection, as seen in Fig 6.

2 to 3 months after impression- an average midfacial smile line, the Case 2 making (Fig 7). At the 1-year follow- preservation of the interdental pa- up, postsurgical periapical and CBCT pillae, utilization of the dual-zone The patient was a 51-year-old wom- radiographs were taken, showing a technique in combination with the an with a history of prior endodon- 1.0-mm gain in crestal bone height hybrid implant design, and shade tic treatment on the maxillary left above the implant platform, a bone integration with the adjacent natural central incisor. Other than slight dis- plate thickness of 3.1 mm at the teeth resulted in a pleasing esthetic coloration (Fig 10a), the patient had implant-abutment interface, and a outcome (Fig 9). The Pink Esthetic been asymptomatic for over 10 years tooth-to-implant distance of 2.0 mm Score18 was evaluated, with the final before a complaint of recent discom- (Fig 8). Even though the patient has outcome scoring 13 out of 14. fort arose. The mesiobuccal location

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a b Fig 8 Case 1. (a) Periapical and (b) CBCT scans at 1 year show a Fig 9 Case 1. The patient’s smile at 1 year posttreatment demon- labial bone plate thickness averaging > 2.0 mm (range: 2.3 to 3.1 strates papillae maintenance and pleasing shade-blending with the mm), as well as a 2.0-mm tooth-to-implant distance. patient’s natural dentition.

had recently developed a 7.0-mm probing depth. A root fracture was suspected on CBCT scans, and immediate implant placement with a provisional restoration was recom- mended (Fig 10b). Following flapless tooth extraction and debridement of the re- sidual socket, a 5.0/4.0 × 15.0–mm a b INV implant with a 12-degree SAC Fig 10 Case 2. (a) Pretreatment condition of the maxillary left central incisor that had pre- was placed, securing the apico- vious endodontic therapy and tooth discoloration. A 7.0 mm mesiobuccal probing depth was measured. (b) A cross-section of a CBCT scan taken before treatment shows root palatal bone, with the long axis fracture and the facial root position with minimal labial plate dimension. emerging through the incisal edge of the surgical guide. The insertion torque required to fully seat the implant was 70 Ncm, and implant sta- first time for impression-making, Case 3 bility quotient (ISQ) values were 70 and the follow-up ISQ values were (buccal) and 74 (palatal), confirming 74 for both facial and palatal as- A 64-year-old woman presented high primary stability. Dual-zone pects, confirming secondary sta- with chronic gingival inflammation in bone grafting with a corticocancel- bility or osseointegration. The pa- her maxillary anterior sextant with re- lous mixture of mineralized bone tient was then referred back to her cent discomfort and severe swelling allograft (Symbios, Dentsply Sirona; restorative dentist for definitive on the facial aspect of the left cen- particle size 250 to 750 microns) restorative treatment where she re- tral incisor (Fig 12a). A root fracture was performed prior to placing a ceived a screw-retained crown (Fig was strongly suspected on periapi- screw-retained temporary crown 11a). CBCT scans at 1 year post- cal and CBCT radiographs (Fig 12b). without occlusal contact. After 3 treatment revealed a range in labial Prior to ITRT, laser-assisted, nonsur- months of healing, the provisional plate thickness of 2.2 to 2.75 mm gical debridement was performed crown was disconnected for the (Fig 11b). with an erbium:YAG laser to reduce

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Fig 11 Case 2. (a) The final restoration was an all-ceramic screw-retained crown delivered about 6 months following implant placement. (b) A cross- sectional CBCT scan taken 16 months after surgery shows adequate reconstruction (range: 2.2 to 2.8 mm) of the labial bone plate.

a b

Fig 12 Case 3. (a) Facial view of a patient who presented with significant marginal gingival inflammation around the facial aspect of the maxillary left central incisor. The 9.0-mm probing depth indicated a vertical root fracture and a dentoalveolar dehiscence defect. (b) Cross-sectional view of a pretreatment CBCT scan shows the absence of facial bone.

a b

inflammation and bacterial load at with an insertion torque of 75 Ncm posttreatment, the provisional crown the site, and the patient returned 1 and ISQ values of 72 both facially was disconnected for the first time, week later for immediate tooth re- and palatally. Dual-zone bone graft- and the ISQ values were taken; they placement. Following atraumatic ex- ing was performed using a compos- increased slightly to 74 facially and 75 traction and thorough debridement, ite graft consisting of a 4:1 ratio of palatally. The patient returned to the a sterile gauze square saturated with cortical, mineralized bone allograft general dentist for definitive restor- a mixture of doxycycline and sterile (Symbios, Dentsply Sirona) and xe- ative treatment, and a screw-retained saline was placed for 3 minutes, fol- nograft (ZenGro, Southern Implants). metal-ceramic crown was delivered 5 lowed by irrigation with sterile saline. A screw-retained provisional crown to 6 months after ITRT. Five weeks The facial socket wall possessed a was fabricated on a PEEK tempo- after delivery of the final crown and dentoalveolar dehiscence defect rary abutment and a dermal allograft 6 to 7 months postsurgery, a CBCT of 9.0 mm. A 4.5/3.5 × 15.0 mm (thickness: 0.4 to 0.8 mm) and was scan revealed a facial bone thick- INV implant with a 12-degree co-axis adapted around the provisional ness over 2.0 mm and crestal height prosthetic connection was placed crown (Fig 13).3,19 At about 3 months coronal to the facial implant platform

The International Journal of Periodontics & Restorative Dentistry

a b Fig 13 Case 3. (a) A dermis allograft (0.4- to 0.8-mm thickness) was trimmed and adapted over the inferior portion of the provisional crown, facing the implant-abutment interface. (b) The length of the soft tissue allograft is determined by the necessity for barrier coverage and graft containment in the region of facial bone loss. (c) Diagrammatic representation of the dermis allograft tucked intrasulcularly to completely cover the hard tissue biomaterial. The soft tissue allograft not only enhances the peri-implant soft tissue c thickness but also protects the native soft tissue from potential irritation from the cortical bone graft particles.

Fig 14 Case 3. (a) The patient received a screw- retained crown, with soft tissue topography harmoni- ous with the adjacent central incisor, 6.5 months after surgery. (b) Five weeks after delivery of the final crown and 6 to 7 months postsurgery, a facial bone thickness > 2.0 mm (range: 2.3 to 2.7 mm) and height coronal to the implant platform were present where a b no bone had previously existed.

where there had not been any at the and prosthetic procedures to opti- in compromised extraction sockets, time of surgery (Fig 14). mize the unique characteristics of this are redefined. hybrid implant and its applications in Respecting the biology of bone, ITRT. With a novel hybrid-designed peri-implant tissues, and the impact Discussion implant, conventional parameters of their violation(s) is critical for long- regarding placement for prosthetic term stability.20,21 The traditional Table 1 demonstrates 10 critical screw retention, primary stability, tapered implant used for ITRT can steps associated with the surgical and coronal gap distance, especially compromise outcomes in several

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Table 1 Clinical Keys in Immediate Tooth Replacement

Flapless minimally invasive tooth extraction Site preparation with incisal edge orientation and prosthetic angle correction Osteotomy extended 1.0 mm beyond the intended implant length Underprepared implant diameter in soft bone Implant placement 3.0–4.0 mm from the midfacial free gingival margin Facial gap distance > 2.0 mm Maintained tooth-to-implant distance > 1.5 mm between the implant and the adjacent teeth Grafting with a slowly resorbing biomaterial adjacent to the labial bone plate and a faster resorbing material in the soft tissue zone Tighten implant mount carrier screw before manual complete seating Absolutely no disconnecting the provisional restoration for at least 3–4 mo postsurgery

ways, as those implants are wider in ridge preservation and minimizing perspective, this novel implant de- the coronal region where the bone long-term recession.29 For this rea- sign features clear advantages over dimension is the most minimal and son and the shortcomings already traditional implants and circum- can be damaged. A narrow coro- mentioned, wider, tapered implants vents potential damage to the labial nal portion provides space for en- are used for ITRT. A hybrid implant plate and its associated long-term hancement of the buccal plate.22 design with a wider, tapered apical consequences. The preservation of Proximity of the implant platform portion that is 50% of the implant circumferential bone at least 1.5 to to the facial bone can result in ex- body’s length can achieve the de- 2.0 mm thick at the crestal level vali- cessive horizontal and vertical bone sired levels of primary stability for dates its use in challenging esthetic loss as extraction socket modeling immediate temporization, with the zones for immediate tooth replace- and remodeling occur.23–26 If the narrower cylindrical coronal half ment therapy.21 implant-tooth distance is smaller providing the above-mentioned ad- The added feature of a 12- when tapered implants are placed, vantages, including a larger socket degree SAC facilitates a facial in- it can affect the level of papilla gap. Maintaining greater distance sertion angle that engages optimal height.12,27,28 Allowing more space to proximal root surfaces and the apicopalatal bone, thereby eluding for augmentation of hard and soft thin facial plate provides a better perforation of the facial wall at the tissues requires a narrower implant opportunity for bone preservation, root apex and allowing screw-reten- diameter at the socket’s crest and augmentation, and soft tissue thick- tion of the restorations.15,31–34 apex. In edentulous sites, this is ness. By facilitating a 2.0-mm fa- These three clinical case series frequently an acceptable solution; cial bone thickness, a stable, more demonstrate the successful use of a however, in immediate extraction vascular support is created longi- hybrid implant, exploiting its wider, situations where primary stability tudinally for hard and soft tissue.9 tapered apical half to achieve in- is attributed to apical and palatal Avoiding mucosal recession post- creased primary stability and us- bone, narrow implants are often treatment is a parameter for long- ing its narrower cylindrical coronal insufficient to establish satisfac- term esthetic success but requires half to favor the biologic factors of tory primary stability for provisional a thicker labial plate to secure the postextraction socket modeling and restoration, which is important for blood supply.30 From a biologic remodeling.

The International Journal of Periodontics & Restorative Dentistry

Conclusions 2. Chu SJ, Salama MA, Garber DA, et 12. Chu SJ, Tan-Chu JHP, Saito H, Östman al. Flapless postextraction socket im- PO, Levin BP, Tarnow DP. Tapered plant placement, part 2: The effects of versus inverted body-shift implants ITRT has become a practical treat- bone grafting and provisional restora- placed into anterior postextraction tion on peri-implant soft tissue height sockets: A retrospective comparative ment option for patients, and im- and thickness—A retrospective study. study. Compend Contin Educ Dent. provements in implant design can Int J Periodontics Restorative Dent 2020;41:e1–e10. now allow for more consistent es- 2015;35:803–809. 13. Howes D. Angled implant design to 3. Levin BP. The dermal apron technique accommodate screw-retained implant- thetic outcomes. By changing the for immediate implant socket manage- supported prostheses. Compend Con- macrogeometry of the implant ment: A novel technique. J Esthet Re- tin Educ Dent 2017;38:458–463. stor Dent 2016;28:18–28. 14. Boyes-Varley JG, Howes DG, Davidge- body, various treatment needs can 4. Levin BP, Chu SJ. Changes in peri- Pitts KD, Brånemark I, McAlpine JA. A be strategically addressed. The implant soft tissue thickness with protocol for maxillary reconstruction three cases presented herein em- bone grafting and dermis allograft: A following oncology resection using case series of 15 consecutive patients. zygomatic implants. Int J Prosthodont body the versatile clinical applica- Int J Periodontics Restorative Dent 2007;20:521–531. tions of a novel hybrid design, even 2018;38:719–727. 15. Sung CE, Cochran DL, Cheng WC, et 5. Bilhan H, Geckili O, Mumcu E, et al. In- al. Preoperative assessment of labial in challenging scenarios, to achieve fluence of surgical technique, implant bone perforation for virtual immediate adequate primary stability for im- shape and diameter on the primary sta- implant surgery in the maxillary esthetic mediate provisional restorations, bility in cancellous bone. J Oral Rehabil zone. A computer simulation study. J 2010;37:900–907. Am Dent Assoc 2015;146:808–819. labial plate dimension, tooth-to- 6. Gamborena I, Blatz M, et al. The all- 16. Lekholm U, Zarb GA. Patient selection implant distance, and ultimately at-once concept: Immediate implant and preparation. In: Branemark PI, Zarb 12 placement into fresh extraction sock- GA, Albrektsson T (eds). Tissue-Inte- consistent Pink Esthetic Scores for ets with final crown delivery. In: Duarte grated Prostheses: Osseointegration patient and clinician success. S Jr (ed). Quintessence Dent Technol in Clinical Dentistry. Chicago: Quintes- 2019;42:2–15. sence, 1985:199–209. 7. Nevins M, Chu SJ, Jang W, Kim DM. 17. Chu SJ, Salama MA, Salama H, et al. The Evaluation of an innovative hybrid dual-zone therapeutic concept of man- Acknowledgments macrogeometry dental implant in im- aging immediate implant placement mediate extraction sockets: A histo- and provisional restoration in anterior morphometric pilot study in foxhound extraction sockets. Compend Contin Special thanks to Dr Guido O. Sarnachiaro dog. Int J Periodontics Restorative Dent Educ Dent 2012;33:524–532. (New York, NY) for the surgical treatment of 2019;39:29–37. 18. Fürhauser R, Florescu D, Benesch T, 8. Chu SJ, Östman PO, Saito H, et al. Haas R, Mailath G, Watzek G. Evalua- case 1, Dr Hal Rosenthaler (Philadelphia, PA) Prospective multicenter clinical cohort tion of soft tissue around single-tooth for the restorative dentistry of case 2, and Dr study of a novel macro hybrid implant in implant crowns: The Pink Esthetic Score. Brian Wilk (Chalfont, PA) for the restorative maxillary anterior postextraction sock- Clin Oral Implants Res 2005;16:639– treatment shown in case 3. No financial sup- ets: 1-year results. Int J Periodontics Re- 644.. port was received for this manuscript. Dr storative Dent 2018;38(suppl):s17–s27. 19. Levin BP, Saito H, Reynolds MA, Chu 9. Östman PO, Chu SJ, Drago C, Saito H, SJ. Changes in peri-implant soft tis- Chu is a consultant for Southern Implants. Nevins M. Clinical outcomes of maxillary sue thickness with bone grafting and The remaining authors declare no conflicts anterior postextraction socket implants dermis allograft. Part II: A comparative of interest. with immediate provisional restorations retrospective case series using a sub- using a novel macro-hybrid implant de- crestal angle correction implant design. sign: An 18- to 24-month single-cohort Int J Periodontics Restorative Dent prospective study. Int J Periodontics Re- 2020;40:539–547. References storative Dent 2020;40:355–363. 20. Spray JR, Black CG, Morris HF, Ochi S. 10. Chu SJ, Tan-Chu JHP, Levin BP, The influence of bone thickness on fa- Sarnachiaro GO, Lyssova V, Tarnow DP. cial marginal bone response: Stage 1 1. Tarnow DP, Chu SJ, Salama MA, et al. A paradigm change in macro implant placement through stage 2 uncovering. Flapless postextraction socket implant concept: Inverted body-shift design Ann Periodontol 2000;5:119–128. placement in the esthetic zone: Part for extraction sockets in the esthetic 21. Chappuis V, Rahman L, Buser R, Janner 1. The effect of bone grafting and/or zone. Compend Contin Educ Dent SFM, Belser UC, Buser D. Long-term provisional restoration on facial-palatal 2019;40:444–452. effectiveness of contour augmentation ridge dimensional change—A retro- 11. Christiaens V, Pitman J, Glibert M, with guided bone regeneration: 10-year spective cohort study. Int J Periodontics Hommez G, Atashkadeh M, De Bruyn results. J Dent Res 2018;97:266–274. 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22. Pluemsakunthai W, Le B, Kasugai S. Ef- 26. Choquet V, Hermans M, Adriaenssens 30. Januário AL, Duarte WR, Barriviera M, fect of buccal gap distance on alveolar P, Daelemans P, Tarnow DP, Malevez C. Mesti JC, Araújo MG, Lindhe J. Dimen- ridge alteration after immediate implant Clinical and radiographic evaluation of sion of the facial bone wall in the ante- placement: A microcomputed tomo- the papilla level adjacent to single-tooth rior maxilla: A cone-beam computed to- graphic and morphometric analysis in dental implants. A retrospective study mography study. Clin Oral Implants Res dogs. Implant Dent 2015;24:70–76. in the maxillary anterior region. J Peri- 2011;22:1168 –1171. 23. Schropp L, Wenzel A, Kostopoulos L, odontol 2001;72:1364 –1371. 31. Ganz SD. Using interactive technology: Karring T. Bone healing and soft tissue 27. Ducommun J, Bornstein MM, Wong In the zone with the triangle of bone. contour changes following single-tooth MCM, von Arx T. Distances of root api- Dent Implantol Update 2008;19:33–38. extraction: A clinical and radiographic ces to adjacent anatomical structures in 32. Kan JY, Roe P, Rungcharassaeng K, et 12-month prospective study. Int J Peri- the anterior maxilla: An analysis using al. Classification of sagittal root posi- odontics Restorative Dent 2003;23:313– cone beam computed tomography. Clin tion in relation to the maxillary anterior 323. Oral Investig 2019;23:2253–2263. osseous housing for immediate implant 24. Nevins M, Camelo M, De Paoli S, et al. A 28. Esposito M, Ekestubbe A, Gröndahl placement: A cone beam computed to- study of the fate of the buccal wall of ex- K. Radiological evaluation of marginal mography study. Int J Oral Maxillofac traction sockets of teeth with prominent bone loss at tooth sites facing single Implants 2011;26:873–876. roots. Int J Periodontics Restorative Brånemark implants. Clin Oral Implants 33. Lau SL, Chow J, Li W, Chow LK. Classifi- Dent 2006;26:19–29. Res 1993;4:151–157. cation of maxillary central incisors—Im- 25. Ferrus J, Cecchinato D, Pjetursson EB, 29. Crespi R, Capparé P, Crespi G, Gastaldi plications for immediate implant in the Lang NP, Sanz M, Lindhe J. Factors in- G, Romanos GE, Gherlone E. Tissue esthetic zone. J Oral Maxillofac Surg fluencing ridge alterations following remodeling in immediate versus de- 2011;69:142–153. immediate implant placement into ex- layed prosthetic restoration in fresh 34. Gluckman H, Pontes CC, Du Toit J. traction sockets. Clin Oral Implants Res socket implants in the esthetic zone. Radial plane tooth position and bone 2010;21:22–29. Int J Periodontics Restorative Dent wall dimensions in the anterior max- 2018;38(suppl):s97–s103. illa: A CBCT classification for immediate implant placement. J Prosthet Dent 2018;120:50–56.

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