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Monolithic zirconia implant-supported restorations connected to titanium bases or titanium inserts are increasing in popularity due to their application in a full digital workflow. These prefabricated abutments are connected to the all-ceramic superstructure by adhesive cementation. Although limited clinical data on the outcomes of this type of restoration are available, a few laboratory studies have shown possible debonding issues. This case report presents a bonding failure of a fixed dental prosthesis supported by titanium bases after short clinical use. A treatment alternative is also proposed using the available digital dental technology.

Purpose: To evaluate survival, complication rates, and bending moments of one- and two-piece zirconia implants restored with different abutment materials and lithium disilicate crowns after aging, compared to titanium implants restored with titanium base-supported lithium disilicate crowns. Materials and methods: Sixty anterior crowns were either screwretained on two-piece titanium implants (C) and two-piece zirconia implants (T1, T2, T3) or cemented on one-piece zirconia implants (T4), resulting in 5 groups with 12 specimens each. For the screw-retained crowns, different abutment materials and implant connections were tested: titanium base with internal conical connection and horizontal joint component (C and T2), zirconia with internal hexagonal connection and horizontal joint component (T1), and polyetherketoneketone with internal hexagonal connection and horizontal joint component (T3). After artificial aging with thermocycling (5°C to 50°C) and chewing simulation (1,200,000 cycles, 49 N, 1.67 Hz), the surviving specimens were loaded until fracture, and the bending moments were calculated. Survival rates and respective differences during aging were analyzed with the Kaplan-Meier log-rank test, while complication rates were compared with chi-square tests. Bending moment data were evaluated using the Kruskal-Wallis test (α = .05). Results: Survival rates after artificial aging ranged from 75% (T1) to 100% (C and T4) without significant differences between the groups (P > .05). Only 41.5% of the surviving specimens were free of complications, while the remaining presented screw-loosening, loss of retention of crowns, or cracks on the crown or implant level. The complication rates varied significantly among the groups (P < .05). The mean bending moments were 173.7 × 20.1 (C), 114.5 × 20.1 (T1), 171.1 × 46.1 (T2), 258.1 × 147.4 (T3), and 194.7 × 30.9 Ncm (T4), and group T1 exhibited significantly lower median bending moment values than the other groups (P < .001). Conclusion: The zirconia one- and two-piece implants presented high survival rates after aging, yet the number of technical complications was high. New prosthetic solutions, such as titanium bases or polyetherketoneketone abutments, may offer a comparable treatment option to restore two-piece zirconia implants. Keywords: ceramic implants, implant abutment, polyetherketoneketone, titanium, two-piece implants, zirconia

The tasks of Working Groups 1 to 6 at the 4th Consensus Meeting of the Oral Reconstruction Foundation were to elucidate clinical recommendations for implant-supported full-arch rehabilitations in edentulous patients. Six systematic/ narrative reviews were prepared to address the following subtopics: (1) the influence of medical and geriatric factors on implant survival; (2) the prevalence of peri-implant diseases; (3) the influence of material selection, attachment type, interarch space, and opposing dentition; (4) different interventions for rehabilitation of the edentulous maxilla; (5) different interventions for rehabilitation of the edentulous mandible; and (6) treatment choice and decision-making in elderly patients. Consensus statements, clinical recommendations, and implications for future research were determined based on structured group discussions and plenary session approval.

Purpose: To analyze the influence of material selection, attachment type, interarch space, and opposing dentition on the prosthetic outcomes of fixed and removable implant complete prostheses (FCIPs and RCIPs, respectively). Materials and Methods: This review was designed as an overview of systematic reviews. An electronic database search was performed to identify scientific literature that reported on FCIPs and RCIPs. The last search was performed in January 2020. The final inclusion of systematic reviews for data extraction was decided by consensus of the authors. The included studies were analyzed qualitatively. Results: A total of 21 systematic reviews (FCIP: n = 11, RCIP: n = 10) out of 5,733 articles initially identified were included for data extraction and interpretation. High overall 5-year and 10-year prosthesis survival rates were shown for FCIPs and RCIPs (93.3% to 100% and 96.9% to 100%, respectively). Chipping/fracture of the veneering material was the most frequent technical complication for FCIPs, and attachment-related complications were the main technical problems for RCIPs. For FCIPs, the effect of prosthetic material was not significant on the technical complications nor the survival rates. No studies were identified that provided direct information on the effect of interarch space in FCIPs and RCIPs. Conclusions: Both FCIPs and RCIPs obtained high overall survival rates, but technical complications cannot be avoided with either prosthesis type. No prosthetic material can be considered as the material of choice over another. Attachment type has no influence on the overall clinical outcomes of RCIPs. The influence of opposing dentition and the required prosthetic space were not investigated sufficiently.

Ziel der Studie war, den Einfluss verschiedener Zemente auf das Farbergebnis von auf Titanbasen zementierten CAD/CAM-gefertigten Lithiumdisilikat-Implantatkronen mittels spektralfotometrischer Analyse zu untersuchen. Multilink HO 0 (Fa. Ivoclar Vivadent, Schaan, Liechtenstein) zeigte dabei das beste Maskierungsvermögen und günstigste Farbergebnis unter den untersuchten definitiven Zementen. Opakere Zementfarben schienen allgemein besser dazu geeignet zu sein, die graue Farbe der Titanbasen zu maskieren. Keywords: CAD/CAM, Zement, Titanbasis, Vollkeramikkrone, Maskierung

Die Diagnostik ist entscheidend für den vorhersagbaren Erfolg einer restaurativen Therapie. Hierbei müssen sich Patient und Zahnarzt vor der Anfertigung der definitiven Restauration auf ein gemeinsames Behandlungsziel einigen, um später Enttäuschungen zu vermeiden. Allerdings kann es schwierig sein, die Patientenwünsche vollständig zu erfassen. Ein nützliches Hilfsmittel zur Lösung dieses Problems sind das diagnostische Wax-up und Mock-up. Mit diesem zeitaufwendigen Verfahren wird jedoch nur eine einzige Variante des möglichen Behandlungsergebnisses visualisiert. Die moderne Digitaltechnik bietet nützliche Funktionen, die bei diesem diagnostischen Schritt zu einer Entscheidungsfindung beitragen können. Im vorliegende Beitrag werden die Möglichkeiten der Digitaltechnik für die prothetische Diagnostik erörtert und die Verfahren anhand von Patientenfällen beschrieben.

The prototyping protocol to evaluate and make the potential adjustments prior to finalization of the monolithic restorations was described by two clinical situations. In the first case report, following the digital impressions using an intraoral scanner (3Shape Trios, 3Shape) for an implant-supported four-unit fixed dental prosthesis, a digital design (3Shape Dental System, 3Shape) was performed and a prototype using subtractive CAM (milling) (PMMA, Telio CAD, Ivoclar Vivadent) was fabricated. The second case highlights the 3D-printed prototyping (additive CAM) (Sheraprint Model Plus UV, Shera) following digital impressions using an intraoral scanner and digital design in a patient requiring two opposing open-end three-unit fixed dental prostheses. By means of prototyping, the esthetic, fitting, and functional properties could be tested and the adjustments were completed on the prototypes. It is suggested that prototyping is an efficient tool that minimizes the clinical adjustment need for the final restoration while improving the communication between the dental practitioner and the technician. Keywords: CAD/CAM, ceramics, diagnostic procedure, digital workflow, prosthodontics

Purpose: To evaluate the effect of cementation protocols on the bonding interface stability and pull-out forces of temporary implant-supported crowns bonded on a titanium base abutment (TiB) or on a temporary titanium abutment (TiA). Materials and Methods: A total of 60 implants were restored with PMMA-based CAD/CAM crowns. Five groups (n = 12) were created: Group 1 = TiB/SRc: crown conditioned with MMA-based liquid (SR Connect, Ivoclar Vivadent); Group 2 = TiB/50Al-MB: crown airborne particle–abraded with 50-μm Al2O3 and silanized (Monobond Plus, Ivoclar Vivadent); Group 3 = TiB/30SiOAl-SRc: crown airborne particle–abraded with 30-μm silica-coated Al2O3 (CoJet, 3M ESPE) and conditioned with MMA-based liquid (SR Connect); Group 4 = TiB/30SiOAl-MB: crown airborne particle–abraded with 30- μm silica-coated Al2O3 (CoJet) and silanized (Monobond Plus); and Group 5 = TiA/TA-PMMA: crown manually enlarged, activated, and rebased with PMMA resin (Telio Lab, Ivoclar Vivadent). Specimens in the TiB groups were cemented using a resin cement (Multilink Hybrid Abutment, Ivoclar Vivadent). After aging (120,000 cycles, 49 N, 1.67 Hz, 5°C to 55°C, 120 seconds), bonding interface failure was analyzed (50x). Pull-out forces (N) (0.5 mm/minute) and modes of failure were registered. Chi-square and Kruskal-Wallis tests were used to analyze the data (α = .05). Results: Bonding failure after aging varied from 0% (Group 5) to 100% (Groups 1, 2, and 4) (P < .001). Mean pull-out force ranged between 53.1 N (Group 1) and 1,146.5 N (Group 5). The pull-off forces were significantly greater for Group 5 (P < .05), followed by Group 3 (P < .05), whereas the differences among the remaining groups were not significant (P > .05). Conclusion: The cementation protocol had an effect on the bonding interface stability and pull-out forces of PMMA-based crowns bonded on a titanium base. Airborne particle abrasion of the crown internal surface and conditioning it with an MMA-based liquid may be recommended to improve retention of titanium base temporary restorations. Yet, for optimal outcomes, conventional temporary abutments might be preferred.