A comparative study on the cytotoxicity of root canal sealers

Objectives: To compare the cytotoxicity between several types of root canal sealers at different time after the obturation in a root canal model in vitro. Methods: 21 extracted single-rooted premolars were divided into seven groups. Each group was instrumented and filled with Roeko-seal, AH-plus, CRCS, Vitapex, Apexit, iodoform paste and one gutta-percha point randomly. All root canals were coronally sealed with glass-ionomer cement. Teeth filled with one gutta-percha point only were controls. All specimens were consecutively extracted with distilled water. The 24h-extracts, 1week-extracts and 5week-extracts of each specimen were investigated for cytotoxicity in L929 fibroblast culture by the MTT assay. Results: In 24h groups, Roeko seal showed no cytotoxicity£»the other five sealers showed cytotoxicity. CRCS displayed the highest degree of cytotoxicity among them and significant difference was found between CRCS and the others(P<0.01). In 1week groups, Roeko seal showed no cytotoxicity; others showed cytotoxicity. Vitapex showed the highest cytotoxicity and followed by Apexit. Significant difference was found between them and the other three groups(P<0.01). In 5week groups, Roeko seal and Vitapex showed no cytotoxicity and had significant difference with the others; the other four sealers showed cytotoxicity. Iodoform paste showed the highest cytotoxicity and significant difference was found between it and the other three groups(P<0.01). Conclusions: (1)Roeko seal is noncytotoxic. (2)AH-plus, CRCS, Apexit and iodoform paste show cytotoxicity at initial stage and the cytotoxicity shows a decreasing trend. (3)Vitapex shows cytotoxicity at initial stage but the cytotoxicity decreases over time, and Vitapex shows no cytotoxicity in 5week-extracts.