Effect of matrix placement on furcation perforation repair.

Furcation perforations are a serious complication during endodontic treatment, and a matrix to aid placement of repair material has been recommended. This study tested the sealing ability of amalgam and Ketac silver placed with and without plaster of Paris as a matrix. A bacterial penetration technique was used to test the seal. Perforations created in the pulpal floor of extracted human mandibular molars were repaired as follows: group 1, amalgam; group 2, amalgam plus plaster as a matrix; group 3, Ketac silver; and group 4, Ketac silver plus plaster (17 teeth/group). Leakage was measured by placing bacteria (Streptococcus sobrinus) in the pulp chamber, and recording the time taken for bacterial growth in a medium bathing the root surface. A plaster of Paris matrix improved the seal with amalgam, but not with Ketac silver. Ketac silver provided the best seal, but all materials showed complete leakage within 22 days.