Ten-year survival rate for cantilevered fixed partial dentures.
METHODS
PubMed (1966-April 2004) provided the primary data source along with the bibliographies from identified articles and reviews. A manual search of two relevant journals (Clinical Implant Dentistry and Related Research, Clinical Oral Implants Research, International Journal of Oral & Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, International Journal of Prosthodontics, Journal of Clinical Periodontology, Journal of Periodontology and Journal of Prosthetic Dentistry published; published 2001-2003) provided a further source of data.


METHODS
Because there were no randomised controlled trials (RCT) that compared fixed partial dentures (FPD) with and without cantilever extensions, other studies were selected if they met the following criteria: were published in the English language; were prospective and retrospective cohort studies; had a mean follow-up of >5 years; included patients who were clinically examined at follow-up; and reported details on suprastructures and described at least one-third of reconstructions as FPD.


METHODS
Two independent reviewers screened articles for inclusion. Disagreements were resolved by discussion and agreement determined by kappa. Two reviewers extracted data on the survival and success of the reconstructions and on biological and technical complications. Failure and complication rates were calculated by dividing the number of events by the total exposure time.


RESULTS
Three prospective and 10 retrospective cohort studies incorporating 700 patients and 816 FPD were included. The mean number of cantilever extensions ranged from 1.1 to 6.0. Meta-analyses gave an estimated survival, after 10 years, of 81.8% [95% confidence interval (CI), 78.2-84.9] and a proportion success of 63% (95% CI, 54.7-70.2). Considering biological complications using Poisson model analyses, the estimated rate of FPD lost because of caries after 10 years was 3.1% (95%CI, 1.0-8.8) and that for loss of vitality was 32.6% (95% CI, 13.9-64.9). The rate of FPD lost because of periodontitis was 1% (95% CI, 0.3-3.0). Cumulative 10-year complication rates were: 2.9% (95% CI, 1.7-5.0) for fracture of abutment tooth; 2.4% (95% CI, 0.6-9.8) for rate of loss as a result of abutment fracture; 16.1% (95% CI, 8.8-28.4) for loss of retention; and 5.9% (95% CI, 3.3-10.4) for material complications.


CONCLUSIONS
Success and survival rates for cantilever FPD are poorer than those for conventional FPD and this is accompanied by frequent biological and technical complications.
Anderson
James D
JD
Division of Prosthodontics, Faculty of Dentistry, Toronto, Ontario, Canada.