Cytotoxicity of Root Canal Sealers on Human Periodontal Ligament Cells

Objectives: The purpose of this study was to determine the cytotoxicity of root canal sealers on human periodontal ligament (HPDL) cells. Methods: Six root canal sealers; Grossman sealer, Pulp canal sealer EWT, Sealapex, AH plus, EndoREZ and RealSeal, were included in this study. Two experiments were conducted as follows. In the first experiment, representing root canal filling without any extrusion of sealers, fresh and set sealers were filled in autoclavable plastic tips, whose ends were placed in contact with cultured HPDL cells. In the second experiment, representing extrusion of sealers, only fresh sealers were placed in a direct contact with the cultured cells. Both experiments lasted 24 hours. The function of mitochondrial dehydrogenase in living cells was assessed by an MTT assay. Results: There was no significant difference in cytotoxicity between the fresh and set sealers in the first experiment. Moreover, there was no significant difference in toxicity between the individual sealers in the fresh and set sealers. In the second experiment, in which sealers directly contacted with the cultured cells, there were significant differences in cytotoxicity on HPDL cells between any type of six sealers and a control (without sealers) (P=0.001). Conclusion: These findings suggest that the cytotoxicity of any root canal sealers on HPDL cells is only found if there is extrusion of root canal sealers that directly contacts with the cells. This study was supported by the Intramural Endowment Fund for Postgraduate Education, Faculty of Dentistry, Chiang Mai University.