Effect of Cantilevers for Implant-Supported Prostheses on Marginal Bone Loss and Prosthetic Complications: Systematic Review and Meta-Analysis

Purpose: The aim of this study was to conduct a systematic review and meta-analysis to evaluate the influence of cantilevers upon implant-supported fixed partial dentures on marginal bone loss (MBL) and prostheticrelated complications. Materials and Methods: An electronic literature search was conducted in the PubMed database by two reviewers (LTM and AM) for articles written in English from June 2003 to January 2013 that were prospective human clinical trials with the clear purpose of appraising the effect of implant-supported fixed partial prostheses on peri-implant bone level and prosthetic complications. Data from the selected studies were extracted to carry out the statistical analysis. Results: Following the method described earlier, from initial research of 643 studies, 4 human clinical studies met the inclusion criteria and provided enough data to include them in the present meta-analysis. For the overall data, the pooled weighted mean (WM) of the MBL was 0.72 mm (range, 0.49 to 1.10 mm), with a 95% confidence interval (CI) of 0.36 to 1.08 mm. For the chi-square test, P = .60, representing a low heterogeneity among studies. MBL around implant-supported restorations with and without cantilevers was not found to be significant between both groups. The weighted mean difference (WMD) was 0.10 mm (favoring the noncantilever group), with a 95% CI = -0.18 to 0.39 mm (P = .47). For the chi-square test, P = .97, also indicating a low degree of heterogeneity between the studies. Conclusion: The dearth of scientific evidence in this matter does not permit clear conclusions to be drawn. However, within the limitations, marginal bone loss does not seem to be influenced by the presence of cantilever extensions. Moreover, minor technical complications were found when a cantilever was present when compared to the control groups.