Method: Primary cultures of TG neurons were obtained from 1 to 2-day old Wistar rats for cytotoxicity evaluation. Viability/cytotoxicity was tested by incubating the cells with different concentrations of root canal sealers for different incubation time intervals (1, 3, 6 and 24 hours). Cells were treated with culture medium containing either the undiluted or the diluted elute (1 in 10 v/v) of the sealers, and pair of dishes with cells from the same culture incubated with only culture medium were considered as negative controls. Images of the cells were captured at X200 magnification and acquired using a microscope equipped with a camera using an image analysis software. The extent of cytotoxicity was quantitated by manually counting the viable cells from the images for each dose and incubation duration. Data was analysed by using one-way analysis of variance with Tukey post hoc test.
Result: Incubation of the TG neurons with culture medium (controls) did not have any significant effect on cell viability. There was no significant change in cell viability after short duration of incubation (1 and 3 h) with any sealers, compared to controls and their preincubation period. Only AH Plus (undiluted) had significant reduction in percentage survival at 3 h (80±4% of preincubation period. GuttaFlow (diluted and undiluted) had similar cytotoxic effect on cells for all periods whereas AH Plus were more cytotoxic than the latest sealers. The signifcant cytotoxic effect of AH Plus was evident for 3, 6 and 24 h incubation periods. The most cytotoxic effect was observed following incubation with undiluted AH Plus.
Conclusion: All the sealers exhibited varying degrees of neurotoxicity depending on their chemical composition.