Setting time affects in vitro biological properties of root canal sealers.

INTRODUCTION: Biocompatibility of root canal sealers is important because of the long-term contact of their eluates and/or degradation products with periapical tissues. The literature still lacks studies about the genotoxic effects of these materials and the influence of setting time on biological properties. The cytotoxicity and genotoxicity of an epoxy resin-based sealer (AH Plus), a single methacrylate-based sealer (EndoRez), and a silicone-based sealer (RoekoSeal) were assessed. METHODS: Chinese hamster fibroblasts (V79) were cultured and exposed to different dilutions of extracts from the sealers that were left to set for 0, 12, and 24 hours before contact with culture medium. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay. Genotoxicity was assessed by the comet assay. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (P < .05). RESULTS: Root canal sealers were statistically more cytotoxic than the untreated control group, except for the silicon-based sealer. Cell viability ranking was the following (from the most to the least cytotoxic): methacrylate-based > epoxy resin-based > silicone-based. The setting time influenced the epoxy resin-based sealer cytotoxicity (decreased at 12 hours) and the general genotoxicity (increased at 24 hours). DNA damage ranking was the following (from the most to the least genotoxic): methacrylate-based > silicone-based = epoxy resin-based. CONCLUSIONS: The setting time had influence on the cytotoxicity of the epoxy resin-based sealer and genotoxicity of all tested sealers. The methacrylate-based sealer was the most cytotoxic, and the silicone-based sealer was not cytotoxic. Genotoxicity was observed for all sealers.

Cytotoxicity and genotoxicity of root canal sealers based on mineral trioxide aggregate.

INTRODUCTION: MTA has good biological properties, and it is a mineralization-inducing material with different indications in endodontics. Initially this material was not recommended as root canal sealer. However, a resin sealer based on mineral trioxide aggregate (MTA Fillapex) was recently released with this indication. Because MTA is in contact with the periodontal tissues, bone, and pulp, it is important to know its cytotoxic and genotoxic effects. The purpose of this study was to evaluate the cytotoxicity and genotoxicity of MTA canal sealer (Fillapex) compared with white MTA cement and AH Plus. METHODS: Chinese hamster fibroblasts (V79) were placed in contact with different dilutions of culture media previously exposed to such materials. Cytotoxicity was evaluated by methol-thiazol-diphenyl tetrazolium assay in spectrophotometer to check the viability rate and cell survival. The genotoxicity was accessed by the micronucleus formation assay. Cell survival rate and micronuclei number were assessed before and after exposure to cement extracts, and the results were statistically analyzed by Kruskal-Wallis and Dunn tests (P < .05). RESULTS: The results showed that the cell viability remained above 50% in white MTA group for all dilutions. AH Plus induced an intermediate cytotoxicity in a dilution-dependent manner, followed by Fillapex MTA. CONCLUSIONS: White MTA group was the less cytotoxic material in this study. Both AH Plus and Fillapex MTA sealer showed the lowest cell viability rates and caused an increased micronucleus formation when compared with control untreated group.