Data sources: PubMed (1966-April 2004) provided the primary data source along with the bibliographies from identified articles and reviews. Manual search of eight relevant journals (published 2001-2003) provided a further source of data.
Study selection: As there were no randomised controlled trials comparing implant therapy with conventional reconstructive dentistry, English language prospective and retrospective cohort studies were selected if; they had a mean follow-up of >/=5 years; included patients who were clinically examined at follow-up; reported details on suprastructures and described at least one-third of reconstructions as fixed partial dentures (FPDs).
Data extraction and synthesis: Two independent reviewers screened articles for inclusion. Disagreements were resolved by discussion and agreement determined by kappa. Data were extracted on the survival proportions of the reconstructions and on biological and technical complications. Biological complications included disturbances in the function of the implant characterized by a biological process affecting the supporting tissues. Technical complications denoted mechanical damage of implants, implant components, or the suprastructures. The number of events for all categories was identified and the corresponding total exposure time of the reconstruction calculated. Failure and complication rates were calculated by dividing the number of events by the total exposure time.
Results: Twenty-one studies of implant supported FPDs, reporting on 16 patient cohorts were included. Of the studies, 16 were prospective and five retrospective. A total of 1336 FPDs supported by 3578 oral implants were involved. Meta-analyses gave an estimated implant survival of 95.4% (95% CI 93.9-96.5) after 5 years and 92.8% (95% CI 90-94.8) after 10 years. Implant failure rate was 48% lower (P=0.006) in the more recent studies. The estimated survival for the FPDs was 95% (95% CI 92.2-96.8) after 5 years and 86.7% (95% CI 82.8-89.8) after 10 years. Four studies provided information on the number of patients free from complications - after 5 years 61.3% (95% CI 55.3-66.8) had suffered no minor or major complications. A random effects Poisson model revealed the rate of biological complications for patients treated with implant supported FPDs to be 8.6% (95% CI 5.1-14.1) after 5 years. For technical complications the cumulative 5 year complication rate varied from 0.4% for implant fracture to 13.2% for veneer fracture.
Conclusions: Although survival rate for implant supported FPDs is high, biological and technical complications are relatively common.