An evaluation of marginal leakage of Class 2 combined amalgam-composite restorations

Forty class 2 cavities were prepared in 20 permanent posterior teeth. In 20 cavities the gingival margin was placed in enamel and in the other 20 cavities in cementum. In every tooth one of the cavities was filled with composite and the other with a combined amalgam-composite restoration. Microleakage at the various interfaces was assessed by dye penetration. It was concluded that microleakage of the combined amalgam-composite restorations was significantly lower than that of the conventional composite restorations.