Ten-year clinical and microscopic evaluation of resin-bonded restorations

A clinical recall was conducted for 103 patients who were functioning with resin-bonded restorations for approximately 10 years. The purpose of this study was to evaluate marginal adaptation of the cast metal retainers. Following clinical evaluations, replicas of incisal and occlusal margins were examined in the scanning electron microscope to determine marginal separation and microscopic patterns of the resin composite interface between metal and tooth. Anterior abutments exhibited better clinical adaptation and fewer voids and debonds than did posterior abutments. Larger microscopic marginal separations were associated with those retainers that had clinically detectable voids or defects.