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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.

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

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.