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Die Bindegewebetransplantation zählt heute zu den Standardverfahren zur Kompensation von Volumendefiziten bei Sofortimplantation. Neue Biomaterialien wie azelluläre Matrices könnten die Gewinnung autogenen Gewebes auf ein absolut notwendiges Minimum reduzieren und damit die Häufigkeit und das Ausmaß postoperativer Beschwerden verringern. Die vorliegende randomisierte Studie verglich die klinischen Therapieergebnisse von Sofortimplantationen in der Oberkieferfront, bei denen sowohl eine knöcherne Augmentation als auch eine Weichgewebeverdickung durchgeführt wurde. Neben anorganischem bovinem Knochenmaterial (ABBM) kam entweder ein Bindegewebeersatz aus porciner Dermis, eine azelluläre dermale Matrix (ADM) oder ein autogenes Bindegewebetransplantat (BGT) zum Einsatz. An der Studie nahmen 20 Patienten (11 Männer, 9 Frauen) mit einem Durchschnittsalter von 48,9 Jahren (21−72 Jahre) teil. Die Zuordnung der Studienteilnehmer zu der Test- (ADM) bzw. Kontrollgruppe (BGT) geschah nach dem Zufallsprinzip. Der Zahnextraktion folgte die sofortige Implantatinsertion. Der bukkale Knochen wurde mit ABBM augmentiert. Eine ADM oder ein BGT diente zur Verdickung des bukkalen Weichgewebes und somit zur Kompensation des erwarteten Verlustes von bukkalem Volumen. Die klinische und volumetrische Nachuntersuchung fand 12 Monate nach Implantatinsertion statt. Bei allen Implantaten hatte eine Osseointegration stattgefunden und die prothetische Versorgung befand sich in situ. Ein Jahr postoperativ betrug die durchschnittliche, linear gemessene Volumenveränderung −0,55 ± 0,32 mm (ADM) bzw. −0,60 ± 0,49 mm (BGT). Patienten der ADM-Gruppe beklagten signifikant weniger postoperative Beschwerden. Bei Sofortimplantation mit Augmentation von Hart- und Weichgewebe führten Ersatzmaterialien und autogene Bindegewebetransplantate zu ähnlichen klinischen Ergebnissen hinsichtlich der gemessenen Volumenveränderungen. Die Anwendung von Ersatzmaterial führte zu signifikant weniger postoperativer Morbidität. Manuskripteingang: 07.01.2021, Annahme: 14.04.2021 Keywords: Sofortimplantation, Weichgewebeverdickung, Bindegewebetransplantat, azelluläre dermale Matrix, anorganisches bovines Knochenmaterial

Connective tissue grafts have become a standard for compensating horizontal volume loss in immediate implant placement. The use of new biomaterials like acellular matrices may avoid the need to harvest autogenous grafts, yielding less postoperative morbidity. This randomized comparative study evaluated the clinical outcomes following extraction and immediate implant placement in conjunction with anorganic bovine bone mineral (ABBM) and the use of a porcine acellular dermal matrix (ADM) vs an autogenous connective tissue graft (CTG) in the anterior maxilla. Twenty patients (11 men, 9 women) with a mean age of 48.9 years (range: 21 to 72 years) were included in the study and randomly assigned to either the test (ADM) or control (CTG) group. They underwent tooth extraction and immediate implant placement together with ABBM for socket grafting and either ADM or CTG for soft tissue augmentation. Twelve months after implant placement, the cases were evaluated clinically and volumetrically. All implants achieved osseointegration and were restored. The average horizontal change of the ridge dimension at 1 year postsurgery was -0.55 ± 0.32 mm for the ADM group and -0.60 ± 0.49 mm for the CTG group. Patients of the ADM group reported significantly less postoperative pain. Using xenografts for hard and soft tissue augmentation in conjunction with immediate implant placement showed no difference in the volume change in comparison to an autogenous soft tissue graft, and showed significantly less postoperative morbidity.

Der Beitrag beschreibt die Anwendung des 3-D-gedruckten Prototyps – ein neues Protokoll zur Bewertung monolithischer Vollkeramikrestaurationen vor deren Fertigstellung. Aus zeitlichen oder wirtschaftlichen Gründen kann es notwendig sein, die definitive Behandlung ohne eine provisorische Phase durchzuführen. In diesen Fällen bietet die Möglichkeit, die endgültige restaurative Behandlung vorherzusagen durch das 3-D-Drucken eines Prototyps und dessen Verwendung als Mock-up, einen weniger kostspieligen und effizienteren Ansatz. Keywords: additive Fertigung, 3-D-Druck, Prototyp, monolithisch, Vollkeramik

In recent years, numerous new dental materials have been introduced as alternatives to metal-ceramics for restorations on teeth and implants. This position paper presents the current evidence and respective clinical recommendations of the European Association for Osseointegration (EAO), one of the scientific partners of the International Journal of Prosthodontics, on material selection for single crowns (SCs) and multiple-unit implant-supported fixed dental prostheses (FDPs). Metal-ceramic restorations can be utilized in most clinical indications and are preferred to ceramic restorations in incidences such as long clinical implant crowns; cantilever implant restorations where one implant is supporting two crowns; implant-supported FDPs with extension units extending more than 7 to 8 mm (premolar size); implant-supported FDPs with more than two pontics; and implant-supported FDPs with small connector diameters due to limited intraocclusal space. Veneered or monolithic zirconia-ceramic and veneered or monolithic reinforced glass-ceramic implant-supported SCs are indicated for most SC cases in both the anterior and posterior areas. Today, implant-supported zirconia-ceramic FDPs that are conventionally veneered cannot be considered the material of first priority due to the pronounced risk for fracture of the framework and catastrophic fracture of the veneering material. Monolithic zirconia FDPs are a promising alternative to veneered implant-supported zirconia-ceramic FDPs. The mechanical stability of the translucent and shaded zirconia differs significantly between the grades of translucency. This must always be considered when clinical indications are recommended. As this specific area of prosthodontics is evolving fast, numerous studies evaluating different material options in implant prosthodontics are currently performed worldwide, and future consensus meetings will refine the present recommendations. The EAO will therefore regularly publish updated position papers on relevant topics.

Purpose: This in vitro study evaluated technical outcomes of monolithic zirconia implant-supported fixed dental prostheses (iFDPs) supported by different designs of titanium base abutments after aging and static load testing. Materials and methods: Sixty three-unit monolithic zirconia (yttrium oxide partially stabilized tetragonal zirconia polycrystals; Y-TZP)iFDPs were produced and divided into four groups: group A-conical titanium base abutments for the prosthesis; group B-cylindrical titanium base abutments for the crown; group C-conical titanium base abutment for the prosthesis and cylindrical titanium base abutment for the crown; group D-cylindrical titanium base abutments for the prosthesis. The samples were subjected to an aging protocol and to continuous static loading until failure and analyzed visually and with specific software. The technical outcomes comprised the occurrence of debonding, screw loosening, deformation and fracture, abutment deformation and fracture, implant deformation and fracture, zirconia chipping and fracture, and bending moments. The Pearson chi-squared test (χ2) and Fischer exact test were used to compare the outcomes. The Kolmogorov-Smirnov test was used to evaluate data distribution of the bending moments. Analysis of variance (ANOVA) was used for the analysis of parametric data distribution, and the Kruskal-Wallis test was used for nonparametric data distribution. Results: After aging, a higher percentage of debonding (P = .042) and micromovement (P = .034) was recorded in group C (P = .042). The conical titanium base abutments had a higher debonding (P = .049) and a higher macromovement rate (P = .05). The static load test showed higher bending moments in group D (P = .001) and lower bending moments in group A (P = .001). Debonding was highest in group C (P = .001) and lowest in group A (P = .002). Complete loss of retention rate was highest in group C (P = .001). The conical titanium base abutment had the highest debonding rate (P = .001) and complete loss of retention (P = .001). The micromovement rate was the highest for cylindrical titanium base abutments for the crown (P = .001). The lowest screw loosening, zirconia chipping, and fracture rate (P = .001) and the highest screw deformation (P = .004) were recorded in group A. The screw deformation rate was lowest in the cylindrical titanium base abutments for the crown (P = .008). Conclusion: The mixed titanium base abutment design comprising one conical and one cylindrical abutment in Y-TZP iFDPs led to the highest debonding rate. The cylindrical titanium base abutment for the prosthesis provided a lower percentage of debonding and the highest load resistance. Keywords: bending moments, debonding, implant-supported fixed dental prostheses, monolithic zirconia, technical complications, titanium base abutment