The marginal microleakage of resin-retained bridges in association with existing resin composite and amalgam restorations

Abstract

The aim of this study was to determine the microleakage associated with resin-retained bridge retainers cemented over amalgam and resin composite restorations. Cavities prepared on the labial surfaces of bovine incisors were restored with either amalgam or a posterior resin composite. Non-precious nickel-chromium alloy frameworks were then attached to the teeth by use of one of four cements: Conclude, ABC, Panavia Ex, and Superbond. The specimens were then stored for two weeks or six months, thermocycled, and tested for microleakage by use of a radioactive tracer and an autoradiographic technique. The results showed that more leakage was associated with the amalgam restorations than with the teeth filled with resin composite. Leakage scores increased with time with both the amalgam and composite restorations, except for the Panavia Ex and ABC materials, respectively.