Full-arch implant supported rehabilitations: A prospective study comparing porcelain-veneered zirconia frameworks to monolithic zirconia.

OBJECTIVES: To evaluate the performance of two types of zirconia frameworks.

MATERIAL AND METHODS: From 2014 to 2016, in a prospective clinical trial 150 patients were rehabilitated with 83 and 110 implant-supported, screw-retained, full-arch ceramic-veneered zirconia (PVZ) rehabilitations and monolithic zirconia with porcelain veneering limited to buccal (MZ) rehabilitations, respectively. Patients were consecutively enlisted according to pre-defined inclusion criteria and evaluated on 4 months intervals. A Kaplan Meier estimator was adopted, and the log-rank test and Wilcoxon test used to test differences in survival and successful function in the two different groups.

RESULTS: The average follow up time (+/- SD) and implant success rate was 608.80 ± 172.52 days with 99.53% implant success for the PVZ group and 552.63 ± 197.57 days with 99.83% success for the MZ group. According to the Kaplan Meier estimator, the mean cumulative survival rate at the 2 year follow up for framework fracture, major chipping, minor chipping, or any of the former combined to occur was 0.99, 0.95, 0.93 and 0.85 for the PVZ group (n=18) and 0.99, 0.95, 0.95 and 0.89 for the MZ group (n=15). No significant differences were found between the two groups.

CONCLUSIONS: Results suggest zirconia as a suitable material for frameworks in full-arch implant-supported rehabilitations. Both groups presented a low incidence of technical complications. When comparing the two different designs the MZ group presented a lower technical complication rate, thus presenting itself as a viable alternative for full arch implant-supported rehabilitations. Further clinical studies with longer follow-ups (5 years) should be performed to evaluate the long-term stability of such rehabilitations. This article is protected by copyright. All rights reserved.