Mutagenicity of endodontic sealers

Four endodontic sealer materials and some of their chemical constituents were subjected to Ames' test for mutagenicity with the Salmonella/microsome assay. Extracts of two zinc oxide-eugenol based materials and of one gutta-percha-zinc oxide-chloroform based sealer were negative in the test. Extracts of a synthetic polymer material, based on epoxy-bis-phenol A, induced mutations in Salmonella typhimurium TA 100 as did extracts of the epoxy-bis-phenol A resin alone. Formaldehyde, an active ingredient from one of the ZnO-based materials, induced mutations in both Salmonella typhimurium TA 98 and TA 100. The mutagenic activity of formaldehyde as well as of the epoxy material was reduced in the presence of rat liver microsomes.