Mutagenic potential of root canal sealers: evaluation through Ames testing.

The mutagenic potential of 12 commercially available dental cements and of two 'pure substances' (zinc oxide and eugenol) used in root canal filling were examined. The cements were prepared according to the manufacturers' indications and set for defined times. Ames tests were performed in their extracts by using Salmonella typhimurium strains TA 98 and TA 100. The results showed that most cements present strong bactericidal activity that disappears or decreases remarkably in time. One of the tested cements showed mutagenicity with both Salmonella strains. Two cements yielded doubtful results. The remaining cements and the two 'pure substances' showed no mutagenic potential. The authors conclude that it is convenient to examine endodontic cements with the Ames test and to eliminate those that present mutagenicity in time.