Systematic review of the survival rate and the biological, technical, and aesthetic complications of fixed dental prostheses with cantilevers on implants reported in longitudinal studies with a mean of 5 years follow-up

Objective A systematic review was carried out to evaluate the success and survival rate of implants supporting cantilever prosthesis, as well as the incidence of technical and biological complications. Material and Methods A MEDLINE search was conducted up to December 2011 for studies with a mean follow-up of 5 years or more. Two independent reviewers screened the retrieved articles and extracted the data independently. Data on survival, failure, mechanical/technical and biological complications were analyzed. Results One-hundred and sixty articles were selected as abstract. Only 18 underwent a full-text analysis and only six were included in the study. The estimated cumulative survival rate of implants supporting cantilevered prosthesis was 98.9% (95% CI: 97.499.5%), whereas ICFDP survival was estimated to be about 97.1% (95% CI: 90.199.2%). Implant failures before prosthetic delivery were not considered. Biological complications were estimated to be 5.7% (95% CI: 4.27.6%) at implant level after 5 years. Technical complications were analyzed: the most common complications were veneer fractures (5-year estimate: 10.1%; 95% CI: 3.716.5%) and abutment screw fractures (5-year estimate: 1.6%; 95% CI: 0.83.5%). Decementation and screw loosening were estimated to be at 5 years 5.9% (95% CI: 1.716.8%) and 7.9% (95% CI: 3.218.2%), respectively. Implant fracture was rare (5-year estimate: 0.7%; 95% CI: 0.14.7%); no framework fracture was reported. Radiographic bone level changes did not yield statistically significant differences. No aesthetic outcome was reported. Conclusions ICFDPS can be considered a reliable treatment: the systematic review assessed that there is no increase in complication rate due to the presence of the cantilever.