A systematic review of the 5‐year survival and complication rates of implant‐supported single crowns

Abstract

Objectives: The objective of this systematic review was to assess the 5‐year survival of implant‐supported single crowns (SCs) and to describe the incidence of biological and technical complications. Methods: An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow‐up time of at least 5 years. Failure and complication rates were analyzed using random‐effects Poisson's regression models to obtain summary estimates of 5‐year proportions. Results: Twenty‐six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta‐analysis of these studies, survival of implants supporting SCs was 96.8% [95% confidence interval (CI): 95.9–97.6%] after 5 years. The survival rate of SCs supported by implants was 94.5% (95% CI: 92.5–95.9%) after 5 years of function. The survival rate of metal–ceramic crowns, 95.4% (95% CI: 93.6–96.7%), was significantly (P=0.005) higher than the survival rate, 91.2% (95% CI: 86.8–94.2%), of all‐ceramic crowns. Peri‐implantitis and soft tissue complications occurred adjacent to 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5‐year observation period. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years, the cumulative incidence of screw or abutment loosening was 12.7% and 0.35% for screw or abutment fracture. For supra‐structure‐related complications, the cumulative incidence of ceramic or veneer fractures was 4.5%. Conclusion: It can be concluded that after an observation period of 5 years, high survival rates for implants and implant‐supported SCs can be expected. However, biological and particularly technical complications are frequent.