Five-Year Results of One-Piece Zirconia Oral Implants Supporting Three-Unit Fixed Dental Prostheses.

OBJECTIVES: The purpose of the present prospective case series was to investigate the clinical and radiological outcome of one-piece zirconia implants fabricated from 3Y-TZP with a moderately roughened endosseous surface (Sa = 1.24 mum) to support three-unit fixed dental prostheses (FDP) after five years in function. MATERIALS AND METHODS: Twenty-seven patients received a total of 54 implants in a one-stage surgery with immediate provisionalization. Peri-implant bone loss was assessed using standardized radiographs. Additionally, soft-tissue parameters were analyzed. Statistical analyses were conducted using linear mixed regression models and Wilcoxon Signed Rank tests (p < 0.05). All patients participated in an annual maintenance program. RESULTS: Eighteen implants were lost up to the 5-year follow-up, resulting in a cumulative survival rate of 66.67%. The mean marginal bone loss of the remaining implants amounted to 1.89 mm. Probing depth, clinical attachment loss, and bleeding on probing increased from prosthesis insertion to the 5-year follow-up, while the plaque index showed no significant changes during the same period. CONCLUSIONS: The investigated one-piece zirconia implant showed low survival rates as compared to previously reported survival rates of one-piece zirconia or two-piece titanium implants. Implant failure was attributed to peri-implantitis, leading to the necessity of implant removal. The implant is not commercially available.