Three-year clinical comparison of survival of endodontically treated teeth restored with either full cast coverage or with direct composite restoration.

STATEMENT OF PROBLEM Little information exists regarding the outcome of crown build-ups on endodontically treated teeth restored with metal-ceramic crowns or with only a direct-placed composite. PURPOSE The aim of this study was to evaluate the clinical success rate of endodontically treated premolars restored with fiber posts and direct composite restorations and compare that treatment with a similar treatment of full-coverage with metal-ceramic crowns. MATERIAL AND METHODS Subjects included in this study had one maxillary or mandibular premolar for which endodontic treatment and crown build up was indicated and met specific inclusion/exclusion criteria. Only premolars with Class II carious lesions and preserved cusp structure were included. Subjects were randomly assigned to 1 of the following 2 experimental groups: (1) teeth endodontically treated and restored with adhesive techniques and composite or (2) teeth endodontically treated, restored with adhesive techniques and composite, and then restored with full-coverage metal-ceramic crowns. Sixty teeth were included in the first group and 57 in the second. All restorations were performed by one operator. Causes of failure were categorized as root fracture, post fracture, post decementation, clinical and/or radiographic evidence of marginal gap between tooth and restoration, and clinical and/or radiographic evidence of secondary caries contiguous with restoration margins. Subjects were examined for the listed clinical and radiographic causes of failure by 2 calibrated examiners at intervals of 1, 2, and 3 years. Exact 95% confidence intervals for the difference between the 2 experimental groups were calculated. RESULTS At the 1-year recall, no failures were reported. The only failure modes observed at 2 and 3 years were decementations of posts and clinical and/or radiographic evidence of marginal gap between tooth and restoration. There was no difference in the failure frequencies of the 2 groups (95% confidence interval, -17.5 to 12.6). There was no difference between the number of failures caused by post decementations and the presence of marginal gaps observed in the 2 groups (95% confidence intervals, -9.7 to 16.2 and -17.8 to 9.27). CONCLUSION Within the limitations of this study, the results upheld the research hypothesis that the clinical success rates of endodontically treated premolars restored with fiber posts and direct composite restorations after 3 years of service were equivalent to a similar treatment of full coverage with metal-ceramic crowns.