International Journal of Periodontics & Restorative Dentistry 5/2017 https://prd-en.quintessenz.de Fachbeiträge auf höchstem Niveau und Farbabbildungen in einer Qualität, die ihresgleichen sucht, haben dieser elegant gestalteten Zeitschrift, die inzwischen in ihr 34. Erscheinungsjahr geht, internationales Renommee und eine treue Leserschaft gesichert. Themen sind die Beziehung zwischen einem gesunden Parodont und präzisen Restaurationen sowie die Implantatintegration auf Grundlage einer umfassenden Behandlungsplanung. Damit vermittelt die Zeitschrift Wissen, das sich in der täglichen Praxis direkt anwenden lässt. • Mit kostenlosem Zugang zur Online-Version recherchieren Abonnenten komfortabel online - auch rückwirkend ab 1992 im Archiv. • Kostenloser Zugang für Abonnenten zur App-Version. This rss-feed covers the latest table of contents including the abstracts. en Quintessence Publ. Comp. Inc. 2017-08-24 International Journal of Periodontics & Restorative Dentistry 5/2017 https://prd-en.quintessenz.de https://www.quintessenz.de/webservices/COVER/j_21_norm.png Editorial: How to Plan Bone Augmentation with Guided Bone Regeneration https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38871 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38871 Grunder, Ueli<br>Page 627 - 627 Long-Term Retrospective Evaluation of Success of Narrow-Diameter Implants in Esthetic Areas: A Consecutive Case Series with 3 to 14 Years Follow-up https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38872 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38872 Froum, Stuart J. / Shi, Ye / Fisselier, Francois / Cho, Sang-Choon<br>Page 628 - 637<br>This retrospective study reports on the outcome of 19 narrow-diameter implants (NDIs) placed in 14 consecutively treated patients 3 to 14 years postloading. Peri-implant bone remodeling, bone loss, esthetic outcomes, and patient satisfaction with the final restoration were evaluated. No implant failures or prosthetic complications were reported, yielding a 100% survival rate and a 84.2% success rate. All 14 patients reported that they were very satisfied with the esthetic results. The average mesial and distal bone remodeling was 1.99 mm and 1.84 mm, respectively. This represents physiologic bone loss post-implant placement. Only 5 implants presented with bone loss, producing an average mesial and distal bone loss of 0.14 mm and 0.17 mm, respectively. Bone loss was measured on the threads of the implant from the time of restoration to the time of follow-up. The bone loss did not exceed 0.2 mm per year on any implant. These screw-retained NDIs present a cost-effective, esthetically acceptable alternative for restoring limited spaces in the anterior esthetic zone. Principles for Vertical Ridge Augmentation in the Atrophic Posterior Mandible: A Technical Review https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38887 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38887 Urban, Istvan A. / Monje, Alberto / Lozada, Jaime / Wang, Hom-Lay<br>Page 638 - 645<br>Guided bone regeneration has become more predictable due to advances in material sciences. Nevertheless, vertical ridge augmentation (VRA) remains a potential challenge due to the complexity of soft tissue management. This becomes more complicated in the posterior atrophic mandible due to limited access and poorer blood supply. As such, a number of critical elements must be taken into consideration in treatment planning. Anatomical structures potentially jeopardize intraoperative adverse events such as bleeding or neurosensory disturbances. The attachment of the mylohyoid often compromises lingual flap advancement. This technical review summarizes the critical factors to be assessed prior to VRA for the posterior mandible and provides a sequenced approach to bone grafting and to attaining a tension-free flap for successful bone regeneration and long-term peri-implant tissue stability. Ten-Year Nonsurgical Periodontal Treatment Protocol with Adjunctive Use of Diode Laser Monitoring Clinical Outcomes in ≥ 6 mm Pockets: A Retrospective Controlled Case Series https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38886 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38886 Roncati, Marisa / Gariffo, Annalisa / Barbieri, Cinzia / Vescovi, Paolo<br>Page 646 - 654<br>The clinical effects of treatment with 808- and 980-nm diode lasers as an adjunct to a uniform and consistent nonsurgical periodontal treatment protocol (NSPTP) for initial probing pockets ≥ 6 mm with a 10-year follow-up were evaluated. In total, 24 patients (16 test cases and 8 control cases) were treated with the NSPTP. The control group (CG) was treated only with nonsurgical conventional therapy, while the test group (TG) received treatment with thermal diode lasers (wavelength of 808 or 980 nm). All patients had recall visits every 3 months and were reevaluated at 1 year after NSPTP. Following the 1-year follow-up, patients were monitored at 4-month intervals for the remaining 9 years. In total, 646 teeth (433 in TG [124 multirooted teeth and 309 single-rooted teeth] and 213 in CG [64 multirooted teeth and 149 single-rooted teeth]) were included. The initial probing pocket depth (PPD) in single-rooted teeth from TG patients decreased from an average of 6.7 mm to 3.3 mm after 1 year, and to 2.3 mm after 10 years. The mean increase in clinical attachment level (CAL) was 3.8 mm. The initial PPD of single-rooted teeth in CG patients decreased from an average of 6.4 mm at baseline to 4 mm after 1 year and 3.3 mm after 10 years. The mean increase in CAL was 2.5 mm in CG. In the TG, the PPDs of multirooted teeth decreased from 6.2 mm to 3.3 mm after 1 year, where they remained stable for 10 years. The mean increase in CAL was 2.2 mm in this group. In the CG, the PPDs for multirooted teeth decreased from 7 mm to 5.8 mm after 1 year and were 5.1 mm after 10 years. The mean increase in CAL was 1.9 mm. The TG had significantly better clinical parameters than the CG, including reduced tooth loss. Compared to conventional debridement alone, the use of thermal diode lasers with NSPTP improves PPD and increases CAL in periodontal pockets ≥ 6 mm over the long term. Interproximal Papilla Stability Around CAD/CAM and Stock Abutments in Anterior Regions: A 2-Year Prospective Multicenter Cohort Study https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38875 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38875 Lops, Diego / Parpaiola, Andrea / Paniz, Gianluca / Sbricoli, Luca / Magaz, Vanessa Ruiz / Venezze, Alvise Cenzi / Bressan, Eriberto / Stellini, Edoardo<br>Page 656 - 665<br>The aim of this study was to compare the interproximal papilla stability of restorations supported by computer-aided design/computer-assisted manufacture (CAD/CAM) abutments to those supported by prefabricated stock abutments in anterior areas over a 2-year follow-up. Abutments were selected depending on implant inclination and thickness of buccal peri-implant soft tissues from the following: zirconia stock, titanium stock, zirconia CAD/CAM and titanium CAD/ CAM. Differences between the height of the papilla tip were measured (REC). Results: REC values of titanium and zirconia CAD/CAM abutments were significantly lower than those of titanium and zirconia stock. The use of titanium and zirconia CAD/CAM abutments is related to better interproximal papillae stability. The Use of Autogenous Gingival Graft for Treatment of Lingual Recession on Mandibular Anterior Teeth https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38869 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38869 Assis, Gonçalo / Nevins, Myron / Kim, David M.<br>Page 666 - 671<br>The goal of this article is to demonstrate the practicality and results of increasing the zone of keratinized tissue on the lingual surface of mandibular anterior teeth via case reports. Calculus is most commonly found on the lingual surface of these teeth, so they are subjected to inflammatory elements resulting in tissue deformation and destruction. Significant attention has been paid to grafting the buccal surface, but there is a paucity of information addressing the lingual surface of mandibular anterior teeth. Gingival augmentation procedures are essential before fixed restorative dentistry to prevent further recession and facilitate plaque control. Connective Tissue Graft Wall Technique and Enamel Matrix Derivative for the Treatment of Infrabony Defects: Case Reports https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38889 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38889 Zucchelli, Giovanni / Mounssif, lham / Marzadori, Matteo / Mazzotti, Claudio / Felice, Pietro / Stefanini, Martina<br>Page 672 - 681<br>The present case report describes a modification of the connective tissue graft wall technique with enamel matrix derivative applied to treat deep vertical bony defects. The technique presented uses a palatal incision to gain access to the bony defect. Deep infrabony defects affecting two maxillary central incisors associated with interdental and buccal gingival recession were treated. At 1 year after surgery, 9 and 6 mm of interdental clinical attachment level gain were seen in cases 1 and 2, respectively. The position of the interdental papilla was improved, and complete root coverage was achieved. Radiographs demonstrated bone fill of the infrabony components of the defects. This report encourages the possibility to improve, in one surgical session, regenerative and esthetic parameters in the treatment of deep infrabony defects. Plasma of Argon Cleaning Treatment on Implant Abutments in Periodontally Healthy Patients: Six Years Postloading Results of a Randomized Controlled Trial https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38870 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38870 Canullo, Luigi / Tallarico, Marco / Penarrocha, Miguel / Corrente, Giuseppe / Fiorellini, Joseph / Penarrocha, David<br>Page 682 - 690<br>The aim of this randomized, match-paired, triple-blinded, controlled clinical trial was to assess the 6-year radiographic changes around customized platform-switched abutments placed according to the one abutment-one time concept, with and without plasma of argon cleaning treatment. A total of 20 periodontally healthy patients received one maxillary implant between the premolars. Immediately before stage 2 surgery and abutment connection, patients were randomly assigned to the control (cleaning protocol by steam) or test group (plasma of argon treatment). Periapical standardized digital radiographs were taken at the time of crown connection (T0) and at 12 (T1), 24 (T2), 48 (T4), 60 (T5), and 72 months (T6) after the final restoration delivery. Primary outcome measures were the success rates of the implants and prostheses and the occurrence of any technical and biologic complications during the follow-up period. Secondary outcome measures were peri-implant marginal bone level changes, bleeding on probing, and plaque score. Two patients (one in test and one in control group) dropped out at the last follow-up. Neither implant nor prosthetic complications were detected in the analyzed patients of both groups during the 6-year follow-up examinations. Radiographic analysis revealed a statistically significant higher mean bone loss in the control group than in the test group at T2 (0.4 ± 0.28 mm; P = .018), T4 (0.52 ± 0.63 mm; P = .037), T5 (0.61 ± 0.70 mm; P = .038), and T6 (0.71 ± 0.66 mm; P = .011), but not at T1 (P = .131). From baseline to the 6-year follow-up, intragroup comparisons showed an absence of statistically significant difference in the test group (P = .08). Conversely, significant differences were found in the control group (P = .01). All implants demonstrated successful periodontal parameters, with no significant differences between groups. The results of this present study indicate that contaminant and bacterial removal from abutments in two-stage implants using plasma of argon could represent a positive strategy to minimize peri-implant bone resorption and longitudinally stabilize esthetic outcomes. Dimensional Change and Microstructure of Intraoral Bone Block Grafts Covered with Platelet-Rich Fibrin and a Barrier Membrane in Ridge Augmentation: A Pilot Investigation https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38883 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38883 Pripatnanont, Prisana / Thanakone, Phetsamone / Leepong, Narit<br>Page 692 - 703<br>This study investigated the dimensional change and microstructure of intraoral bone block grafts covered with platelet-rich fibrin (PRF) and a barrier membrane in ridge augmentation. Seven patients were included, with 18 implant sites (10 ramus and 8 symphysis). The average final ridge width gains in the ramus from cast-based measurement (3.86 ± 0.87 mm) and cone beam computed tomography measurements (3.63 ± 1.38 mm) were not different from the symphysis (3.36 ± 2.26 mm and 3.44 ± 1.52 mm, respectively). Ridge width reduction of the ramus (−10.46 ± 10.55%) was higher than the symphysis (−5.04 ± 2.08%). The ramus showed bone volume fractions from the microcomputed tomography (84.66 ± 8.36%) and percentage of bone area from histomorphometry (80.29 ± 12.03%) that were comparable to those for the symphysis (83.13 ± 8.1% and 84.98 ± 14.50%, respectively). The dimensional change of the intraoral block graft covered with PRF and a resorbable membrane was minimal, and the symphysis graft was less resorbed than the ramus graft. Nevertheless, their microstructures were comparable. Using MicroCT to Assess Periodontal Regeneration Outcomes-Comparison of Image-Based and Histologic Results: A Case Report https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38884 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38884 Rebaudi, Alberto / Trisi, Paolo / Pagni, Giorgio / Wang, Hom-Lay<br>Page 704 - 711<br>The purpose of this study was to compare microcomputed tomography (microCT) and histologic analysis outcomes of a periodontal regeneration of a human defect treated with a polylactic- and polyglycolic-acid copolymer. At 11 months following the grafting procedure, the root with the surrounding periodontal tissues was removed and analyzed using microCT and histologic techniques. The results suggest that microCT three-dimensional analysis may be used in synergy with two-dimensional histologic sections to provide additional information for studying the regeneration outcomes normally reported by histologic biopsies in humans. Additional data is needed to validate these findings. Prognosis of Dental Implants Immediately Placed in Sockets Affected by Peri-implantitis: A Retrospective Pilot Study https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38868 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38868 Anitua, Eduardo / Piñas, Laura / Begoña, Leire / Alkhraisat, Mohammad Hamdan<br>Page 712 - 719<br>The aim of this study was to describe a protocol and analyze the outcomes of immediate replacement of failed implants due to peri-implantitis. A total of 17 patients (mean age: 58 ± 10 years) had 22 failed implants that were immediately replaced. One implant failed 16 months after insertion, resulting in an implant survival rate of 94.7%. The mean follow-up time was 40 ± 16 months (range: 9-52 months) after insertion. Mesial and distal bone loss were 0.89 ± 0.62 mm and 0.97 ± 0.66 mm, respectively. Immediate implant replacement could be considered in the management of implant failure due to peri-implantitis. Influence of Abutment Height on Maintenance of Peri-implant Crestal Bone at Bone-Level Implants: A 3-Year Follow-up Study https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38880 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38880 Nóvoa, Lourdes / Batalla, Pilar / Caneiro, Leticia / Pico, Alexandre / Liñares, Antonio / Blanco, Juan<br>Page 721 - 727<br>In this 3-year follow-up study, peri-implant bone loss at bone-level implants was evaluated with two definitive abutment heights: 1 mm and 2.5 mm. Peri-implant bone loss was defined as the distance between the implant shoulder and the first bone-to-implant contact from the time of loading to the 36-month follow-up, estimated using periapical radiographs. The bone loss was increased at the time of follow-up, to 1.30 mm (95% confidence interval [CI]: 0.70-1.89 mm; SD = 1.89) and 0.33 mm (95% CI: 0.11-0.55; SD = 0.59) at 36 months in short and long abutments, respectively. Placement of short abutments induced higher periimplant bone loss at bone-level implants during a peri-implant recall program. Immediate One-Time Low-Profile Abutment to Enhance Peri-implant Soft and Hard Tissue Stability in the Esthetic Zone https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38882 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38882 Pelekanos, Stavros / Pozidi, Georgia<br>Page 728 - 735<br>Reductions in peri-implant bone height have been acknowledged as a normal consequence of implant therapy. Various restorative factors contribute to this phenomenon. One is repeated abutment retightening, which causes a mechanical disruption at the implant-abutment interface, leading to soft tissue recession. Several investigators proposed placement of the definitive abutment after implant placement as a solution to the problem. The definitive use of an intermediate abutment after implant placement seems to positively affect the soft tissue response. This article aims to present a prosthetic sequence for achieving peri-implant tissue stability in the esthetic zone. Relationship Between Clinical and Histologic Periodontal Biotypes in Humans https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38878 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38878 Gonçalves Motta, Sergio Henrique / Ferreira Camacho, Marcos Paulo / Quintela, Danielle Carvalho / Santana, Ronaldo B.<br>Page 736 - 741<br>Histologic and histomorphometric evaluations of gingival biopsy samples of patients presenting either a thick or a thin gingival biotype were performed. Fullthickness gingival biopsy samples were obtained and processed for histologic and histometric evaluations. Thickness of the keratinized mucosa or gingiva was found to be increased in the thick biotype. Specifically, the connective tissue layer was thicker with no change in epithelial thickness. In conclusion, gingival transparency appears to be an adequate, clinically useful method to classify the gingival biotype. The thin gingival biotype is manifested by reduced connective tissue thickness; therefore, biotype conversion or enhancement may be based on augmentation of the connective tissue portion of the gingival tissues. Oral Rehabilitation of a Severe Periodontally Involved Patient with Mucous Membrane Pemphigoid: A 15-Year Follow-up Case Report https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38876 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38876 Megarbane, Jean-Marie / Freiha, Cécile / Mokbel, Nadim<br>Page 743 - 748<br>Mucous membrane pemphigoid (MMP) refers to a group of chronic autoimmune subepithelial diseases distinguished by erosive lesions of the mucous membranes and skin. Its treatment consists of inhibition of the inflammatory reaction by means of corticosteroids and symptomatic medication. This is a report of a patient suffering from a combination of MMP and severe generalized chronic periodontitis. The patient was treated with oral corticosteroids, initial phase therapy, extraction with immediate implant placement, and periodontal surgery where the prognosis was questionable. The patient has been followed up for 15 years. Periodontal therapy with immediate implant placement was determined to be a viable modality to achieve a total rehabilitation of this patient suffering from MMP combined with severe generalized chronic periodontitis. Enhancing Root Eminence and Papilla Contour Using Single, Contoured, Subepithelial Connective Tissue Autografts for Recession Coverage https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38874 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38874 Lareau, Donald E. / Hinrichs, James E. / Kotsakis, Georgios A.<br>Page 750 - 757<br>Current techniques using autogenous soft tissue in periodontal plastic surgery have limitations in the number of teeth that can be treated and may result in suboptimal esthetic results. The innovative use of single, contoured grafts reported in this article overcomes the drawbacks associated with these techniques by more efficient use of available donor tissue. Autogenous tissue is used to graft each individual tooth, leaving the interdental areas uncovered. Multiple teeth-in some cases an entire arch-can be treated in one session, providing consistent and predictable reestablishment of the normal scalloped gingival architecture and convex root eminence. Epithelial Inclusions Following a Bilaminar Root Coverage Procedure with a Subepithelial Connective Tissue Graft: A Histologic and Clinical Study https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38885 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38885 Romano, Federica / Perotto, Stefano / Cricenti, Luca / Gotti, Stefano / Aimetti, Mario<br>Page 245 - 252<br>The aim of this study was to histologically examine any epithelial cell inclusions in submerged subepithelial connective tissue graft (SCTG) after clinical healing was achieved. A total of 16 patients with Miller Class I or II gingival recessions were consecutively treated with a bilaminar procedure. At 2 months after surgery, a gingival tissue specimen was harvested from all SCTG-treated sites and stained with hematoxylin-eosin. The histologic evaluation revealed connective tissue in active reorganization without epithelial inclusions in 14 of the 16 tissue specimens. In the remaining 2 specimens, epithelial islands were observed deep in the connective tissue. In one case they developed in a solid cystic space, while in the second case they were strictly integrated in the lamina propria. Complete recession coverage was obtained in 14 of the 16 treated defects, with a mean root coverage of 95.1% ± 14.2% at 12 months. Identification and Efficacy Ranking of Allograft and Xenograft for Extraction and Ridge Preservation Procedures https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38879 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38879 Natto, Zuhair S. / Yaghmoor, Wael / Bannuru, Raveendhara R. / Nevins, Myron<br>Page 253 - 260<br>The objective of this network meta-analysis was to identify and rank different ridge preservation procedures using allograft, xenograft, or extraction only by dimensional changes in ridge width and height after tooth extraction. Electronic and hand searches of several databases were performed in September 2016 to identify randomized controlled trials on extraction and ridge preservation with 3 to 7 months of follow-up. Eight studies were included in the network metaanalysis. The total number of teeth included in these trials was 466, which were randomly assigned to treatment groups. The effect sizes of ridge width ranged from −2.01 (credibility interval [CrI]: −2.92 to −1.04) for the least efficacious treatment (extraction only) to −0.21 (CrI: −2.09 to 1.67) for the most efficacious treatment (xenograft with barrier). For height, they ranged from −0.35 (CrI: −3.82 to 3.17) for the most efficacious treatment (freeze-dried bone allograft with barrier) to −1.11 (CrI: −6.21 to 3.88) for the least efficacious treatment (extraction). No significant difference was detected between treatments nor inconsistency between the direct and indirect estimates. None of the selected interventions were statistically significant compared with any other treatment. All treatment options resulted in minimal bone loss in alveolar ridge width and height. Immediately Loaded, Implant-Supported Overdentures Retained by a Milled Bar: An Up-to-5-Year Retrospective Clinical Study https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38888 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38888 Villa, Franco / Grassi, Felice Roberto / Popovic, Maja / Sordillo, Raffaele / Kalemaj, Zamira<br>Page 261 - 269<br>This study was conducted as an up-to-5-year retrospective investigation estimating survival rate, marginal bone loss (MBL), patient satisfaction, complications, and required prosthodontic maintenance for immediately loaded, milled bar-retained, implant-supported overdentures (ISOs). A total of 60 patients, 69 overdentures, and 179 implants were examined. The implant survival rate was 96.65%, and the mean MBL was 0.57 mm (SD 0.52). High subjective satisfaction ratings, ranging from 3 to 5 with a mean of 4.3 (SD 0.6), were observed. The incidence of complications and prosthetic maintenance was low and required short standard appointments. The present findings encourage the use of immediately loaded, milled bar-retained ISOs. Effects of Platelet-Rich Fibrin on Palatal Wound Healing After Free Gingival Graft Harvesting: A Comparative Randomized Controlled Clinical Trial https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38881 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38881 Ozcan, Mustafa / Ucak, Onur / Alkaya, Bahar / Keceli, Seray / Seydaoglu, Gulsah / Haytac, M. Cenk<br>Page 270 - 278<br>This study was conducted to evaluate the effects of platelet-rich fibrin (PRF) on palatal wound healing after free gingival graft (FGG) harvesting. A total of 125 patients were randomized after FGG: PRF with butyl-cyanoacrylate (BC) adhesive (PRF group; n = 42), BC adhesive alone (BC group; n = 42), and sterile wet gauze compression (WG group; n = 41). Bleeding, pain, epithelialization, feeding habits, and sensation scores were recorded for different time points. Statistically significant differences were found for all parameters in favor of the PRF group (P = .0001). PRF may provide significant benefits for wound healing parameters and patients' postoperative course after palatal graft harvesting. Morphologic Patterns of the Atrophic Posterior Maxilla and Clinical Implications for Bone Regenerative Therapy https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38877 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38877 Monje, Alberto / Urban, Istvan A. / Miron, Richard J. / Caballe-Serrano, Jordi / Buser, Daniel / Wang, Hom-Lay<br>Page 279 - 289<br>Regenerative therapies are commonly needed prior to implant placement in the posterior maxilla following tooth extraction. The aim of this study was to investigate the anatomical features of the atrophic posterior maxilla that might affect surgical approach selection and technique and risk of intra- and postoperative complications. Cone beam computed tomography files were screened to identify pristine atrophic maxillary ridges in need of bone augmentation (ridge height < 10 mm). Ridge height and width and lateral wall thickness (LWT) were measured at different levels, and palatonasal recess and lateral wall morphology were calculated. The influence of site was assessed using generalized estimation equations. The linear correlation between parameters was estimated with Pearson coefficient, and principal component analysis (PCA) was performed to establish patterns of multiple correlations. In the 433 edentulous sites and 6,062 measurements analyzed, the strongest correlations corresponded to LWT measurements at the different levels. Most of the parameters examined presented linearity (P < .001), allowing establishment of four main morphologic patterns according to anatomical features. The anatomical structures of the atrophic posterior maxilla follow linear patterns that might predict complications due to an anatomical feature and thus success in regenerative therapy. Clinical Outcomes of Socket Preservation Using Bovine-Derived Xenograft Collagen and Collagen Membrane Post-Tooth Extraction: A 6-Month Randomized Controlled Clinical Trial https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38873 https://prd-en.quintessenz.de/index.php?doc=abstract&abstractID=38873 Iorio-Siciliano, Vincenzo / Blasi, Andrea / Nicolò, Michele / Iorio-Siciliano, Alessandro / Riccitiello, Francesco / Ramaglia, Luca<br>Page 290 - 296<br>The aim of this study was to evaluate the clinical remodeling of the alveolar socket following the application of bovine-derived xenograft collagen and collagen membrane compared to natural spontaneous healing during the first 6 months following tooth extraction. A total of 20 patients with 20 fresh alveolar sockets were randomly allocated into a test or control group. After a 6-month follow-up period, surgical reentry was performed and implants were placed. Significant statistical differences were recorded in terms of vertical and horizontal bone changes between the test and control groups. Within the limitations of this study, socket preservation procedures may provide more favorable conditions for subsequent implant placement.