Three-year analysis of zirconia implants used for single-tooth replacement and three-unit fixed dental prostheses: A prospective multicenter study

AimThe aim of the present investigation was to evaluate clinically and radiographically the outcome of zirconia oral implants after 3years in function. Materials and methodsIn 60 patients in need of either a single-tooth replacement or a three-unit fixed dental prosthesis (FDP), a total of 71 one-piece zirconia implants were placed and immediately restored with temporary fixed prostheses. After a period of at least 2months in the mandible and at least 4months in the maxilla, zirconia-based reconstructions were cemented. The implants were clinically and radiologically examined at implant insertion, prosthetic delivery, at 6months and then yearly up to 3years. A linear mixed model was used to analyze statistically the influence of prognostic factors on changes in the marginal bone level. ResultsSeventy-one implants (48 in the mandible, 23 in the maxilla) inserted in 60 patients were restored with 49 crowns and 11 FDP. One patient lost his implant after 5weeks. Five patients with one implant each could not be evaluated after 3years. Based on 55 patients with a total of 66 implants, the mean survival rate was 98.5% after 3years in function. A statistically significant mean marginal bone loss (0.70mm0.72mm) has been detected from implant insertion to the 3-year follow-up. The largest marginal bone loss occurred between implantation and prosthetic delivery (0.67mm +/- 0.56mm). After delivery, no statistically significant bone level change was observed (0.02mm +/- 0.59mm). None of the investigated prognostic factors had a significant influence on changes in the marginal bone level. ConclusionsAfter 3years in function, the investigated one-piece zirconia implant showed a high survival rate and a low marginal bone loss. The implant system was successful for single-tooth replacement and three-unit FDPs. Further investigations with long-term data are needed to confirm these findings.