Objective To evaluate the effect of internal matrix on sealing ability and furcal appearance of perforations repair with amalgam and resin. Methods Perforations created in the pulpal floor of human extracted molars were repaired as follows: Amalgam, amalgam plus calcium sulfate, light-cured resin, and resin plus calcium sulfate（15 teeth/group）. The furcal appearance of samples was evaluated under an operating microscope after repair.
With the leakage test device, coronal 1 mol/L glucose solution was forced toward the pulpal floor. Leakage was measured by the concentration of leaked glucose in bottom reservoir at 1, 2, 4, 7, 10, 15 and 20 days with enzymatic glucose oxidase method. Results No significant difference was found between group 1 and group 2（P>0.05）. Leakage in group 4 was obviously lower than group 3（P
