A systematic review of survival rates of osseointegrated implants in fully and partially edentulous patients following immediate loading

Background: The aim of this systematic review was to evaluate the survival rates of immediately loaded implants after at least five years. Besides implant failure, the amount of marginal bone loss around implants and the complication type were assessed. Methods: The electronic search was undertaken on Medline, Scopus, and Cochrane Central Register of Controlled Trials using key terms such as: “immediate loading”, “immediate function”, “immediate restoration”, “immediate temporization”, “dental implants”, “fully edentulous patients”, “partially edentulous patients”. The search terms were combined using the Boolean operators AND, OR. The last electronic search was performed on 15 February 2018. Two authors independently screened the studies, extracted the data, and assessed the risk-of bias. The main outcomes recorded for each study were: implant and prosthesis success and survival, marginal bone level change, incidence and type of complications. Kaplan–Meier analysis was used to estimate cumulative survival rates. Results: Thirty-four prospective studies with at least five-year follow-up, published between 2007 and 2017 were included. A total of 5349 immediately loaded implants in 1738 patients were analyzed. The mean follow-up was 72.4 months (median 60 months, 95% confidence intervals (CI): 64.53, 80.25 months, range 60 to 147 months). The mean weighted implant survival was 97.4% (median 98.15%, 95% CI: 96.29%, 98.54%, range 83.80% to 100%). Cumulative survival rate of implants placed in the mandible was significantly higher than for the maxilla (p < 0.01). No significant difference in failure rate was found among the types of prosthesis employed (p = 0.27). The mean peri-implant bone level change at the end of the follow-up in each study ranged from 0.3 to 1.7 mm. Conclusion: Immediate loading of implants appears to have long-term predictability and success rate under well-defined circumstances.