Cytotoxic Effects of Five Root Canal Sealers on Mouse Fibroblasts

Objective: To compare the cytotoxic effects of five different root canal sealers using an L929 mouse fibroblast cell-line. Methods: Eighty samples of each sealer (AH Plus, Apexit Plus, CU Sealer, ProcoSol, and RealSeal) were fabricated in sterile cylindrical plastic blocks (4 X 2 mm), covered top and bottom with cover slips, then divided into 2 groups (fresh vs aged specimens). Specimens were incubated for 1 day (fresh group) or 7 days (aged group) in a humidified atmosphere, at 37°C, before being placed in a Petri-dish filled with culture media using the ratio of 1 ml per 1.25 cm2 of surface area, according to ISO Standard 10993-12. After incubation for 24 hours at 37°C, 300 µl of undiluted eluent was added to the fibroblast cell-line cultures. The fibroblast cultures were then incubated for 6 or 24 hours per group. Cytotoxicity was measured using an MTT colorimetric assay. For each material, differences in cytotoxicity after 6 or 24 hours of incubation were analyzed using the paired t-test. For each time period, differences in cytotoxicity were analyzed using one-way ANOVA. Post hoc multiple comparisons were performed using the Bonferroni/ Tamhane T2 test. For the interaction of material types and groups, differences in 24 hour-incubation cytotoxicity were analyzed using two-way ANOVA. Statistical significance was set at p<0.05. Results: In the fresh specimen group, the length of incubation time correlated positively with the degree of cytotoxicity for all sealer types. In the aged specimen group, ProcoSol, CU Sealer, Apexit Plus and RealSeal showed increased cytotoxicity after 24hr incubation. For the aged specimen group, only AH Plus showed decreased cytotoxicity after 24hr. Conclusion: AH Plus was significantly less cytotoxic than other sealers in both fresh and aged groups (p<0.05). CU Sealer, ProcoSol, Apexit Plus and RealSeal were similarly cytotoxic in both fresh and aged groups.