Evaluation of the cytotoxicity of different root canal sealers on L929 cell line by MTT assay.

The purpose of this study was to evaluate the cytotoxic effects of commercially available root canal sealers [Sealite Ultra (SU), Tubli-Seal (TS), Tubli-Seal EWT (TS-EWT), Pulp Canal Sealer (PCS), Pulp Canal Sealer EWT (PCS-EWT), Endomethasone N (En N), and Apexit Plus (AP)] on L929 cells by using MTT assay. After incubation with each sealer's extract at 37°C in a humidified air atmosphere containing 5% CO(2 )for 24 h, MTT (5 mg/mL) in saline was added into each well and further incubated at 37°C for 4 h. Formazan precipitate was dissolved in a buffer containing 23% sodium dodecyl sulfate and 50% N, N-dimethylformamide (pH 4.7). Optical densities of dissolved formazan were read using a microplate spectrophotometer. AP, TS, and TS-EWT showed no cytotoxicity at any dilution tested. Other sealers exhibited some degree of cytotoxicity at the 1/4 and 1/2 dilutions. PCS-EWT and SU exerted more potent cytotoxicity at 1/2 dilution than the other sealers.