In vitro cytotoxicity evaluation of endodontic sealers exposed to heat before assay.

During warm-vertical condensation of gutta-percha, endodontic sealers are exposed to temperatures that potentially alter their cytotoxicity profiles. This study investigated the effects of heat on sealer toxicity by using the CyQuant assays for cell adhesion and proliferation of human gingival fibroblasts. Seven sealers were exposed to one of the following temperatures for 10 min before assay: 23 degrees C, 43 degrees C, or 100 degrees C. Adhesion data were used to determine percentage of cells bound, and proliferation data were used to determine percentage of change in cell number from 24 to 72 h, for each sealer at each temperature. The temperatures of 23 degrees C, 43 degrees C, and 100 degrees C were significantly different in both the adhesion and proliferation assays. Sealer type and temperature were significant variables in both assays. The changes in toxicity measured by adhesion and proliferation for each sealer were not always similar. Roth 801 and Roth 811, after exposure to 100 degrees C, showed enhanced adhesion but not proliferation, whereas Kerr PCS and Dentalis, after exposure to 100 degrees C, showed decreased adhesion but enhanced proliferation. AH Plus and AH26 showed an increase in adhesion and proliferation after heat exposure, whereas Sealapex remained virtually unaffected.