(PR072) Biological Effects of Root Canal Sealers on Pre-osteoblast MC3T3-E1 Cells

Objectives: Root canal sealers play a pivotal role in the effective sealing of the root canal during non-surgical endodontic treatment. Although not considered standard practice, the extrusion of sealers from the apical foramina and other exit portals is relatively common, with literature reporting a prevalence of 32.3%. Such extrusion leads to direct contact between endodontic sealers and living tissues at the root apex and periapical region, making their biocompatibility a critical consideration. Therefore, this study aims to evaluate the biological effects of various sealers used in endodontics.

Methods: The biological impact of calcium silicate-based sealer (Endosequence®), resin-based sealer (AH26®), zinc oxide-eugenol-based (Pulp Canal Sealer™) sealer, and calcium hydroxide-based sealer (Sealapex™) compared to no sealer (control), was assessed using the MC3T3-E1 mouse pre-osteoblast cell line. Uniformly-sized sealer pellets were cultured with cells, and mineralization was analyzed using ARS staining. Osteogenic marker expression was evaluated via real-time PCR, while cell proliferation was assessed with WST-1 staining. Western blot examined JNK and P38 MAPK pathway activation to assess cellular stress induced by each sealer. Two-way ANOVA with p-values less than 0.05 were considered statistically significant.

Results: Our findings indicate that the selected sealers induced a range of phenotypic responses in cultured cells, reflecting distinct capacities for mineralization, cellular proliferation, and the activation of stress-related pathways.

Conclusion: Given the varying effects of sealers on cellular behavior, careful consideration of sealer choice should be tailored to clinical contexts. Future studies should explore in vivo models to further elucidate the long-term biological and clinical implications of sealer-induced responses.