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

Ronald E. Jung, Bjarni E. Pjetursson, Roland Glauser, Anja Zembic, Marcel Zwahlen, Niklaus P. Lang
Clin. Oral Impl. Res. 19, 2008 / 119–130

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. We performed an electronic MEDLINE search complemented by manual searching 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. 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% . The survival rate of SCs supported by implants was 94.5% after 5 years of function. The survival rate of metal–ceramic crowns, 95.4% was significantly higher than the survival rate of all-ceramic crowns which was 91.2%. Peri-implantitis and soft tissue complications occurred adjacent to 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2mm 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%. From our result we can con conclude 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.