Outcome of zirconia partial fixed dental prostheses made by predoctoral dental students: A clinical retrospective study after 3 to 7 years of clinical service.

Statement of Problem: Zirconia has an established role in fixed prosthodontics, especially for single crowns. Whether it is durable enough for fixed dental prostheses (FDPs) in the long term is yet unclear.
Purpose: The purpose of this retrospective study was to evaluate the outcome of FDPs made by predoctoral students after 3 to 7 years of clinical service.
Material and Methods: A total of 102 patients received 120 zirconia FDPs (range, 3-12 units; mean, 4.5 units) between 2007 and 2010. Materials used were Zirkonzahn Zirconia (Zirkonzahn), NobelProcera Zirconia (Nobel Biocare), and Prettau Zirconia (Zirkonzahn). Veneering porcelain was hand-layered on Zirkonzahn Zirconia (GC Initial Zr; GC Europe) and Nobel Procera Zirconia (VITA VM 9; VITA Zahnfabrik). Prettau Zirconia was monolithic and had no veneering porcelain. Success and survival rates were calculated using Kaplan-Meier survival analysis. Ethics approval was obtained from the Ethical Committee of the Northern Ostrobothnia Hospital District (100/2013).
Results: The 76 participants examined (75%) had received 88 zirconia FDPs. The mean follow-up period was 4.9 years (range, 3-7 years). The most common complication was chipping of the veneering porcelain in 13 of 88 FDPs (14.7%). The success rate of the zirconia-based partial FDPs after 4.9 years was 89%, and the survival rate was 100%.
Conclusions: The success rate of the zirconia-based partial FDPs after 4.9 years was 89%, and the survival rate was 100%.
(Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)