Evaluation of the Cytotoxic Effect of Calcium Silicate-Based Bioceramic Sealers: An In Vitro Comparative Study

Calcium silicate-based bioceramic sealers have become increasingly popular due to their biocompatibility, bioactivity, and potential for periapical tissue integration. However, evaluating their cytotoxic effects on fibroblast cell lines remains limited.

The aim of this study was to compare the cytotoxic effects of two commercially available calcium silicate-based bioceramic root canal sealers on L929 mouse fibroblast cells, using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay to assess cell viability following exposure to serial dilutions (100%-6.25%) of sealer extracts.

Leachates were prepared by incubating for 24 hours in 2 mL of serum-free Dulbecco's Modified Eagle Medium (DMEM) through 0.2 μm polyethersulfone (PES) syringe filters from sets of specimens from both sealers. L929 mouse fibroblast cells were seeded at a density of 1×104 cells/well and treated with five serial dilutions (100%, 50%, 25%, 12.5%, and 6.25%) of sealer extracts. Cell viability was determined spectrophotometrically at 570 nm by MTT assay. Dimethyl sulfoxide (DMSO) (10%) was used as a positive control, and cells without treatment were used as a negative control.

Cell viability was significantly decreased with both 100% and 50% concentrations of Bio-C Sealer (Angelus Indústria de Produtos Odontológicos S/A, Londrina, Brazil) (4.89% and 9.31%, respectively) and Prime MTA Bioceramic Root Canal Sealer (Prime Dental Products Pvt Ltd, Maharashtra, India) (5.28% and 8.30%, respectively). However, at lower concentrations, cell viability recovered significantly and approached the control level at 6.25%. At 25% concentration, a statistically significant difference (p=0.002) was observed, with Bio-C Sealer showing better cytocompatibility (92.86% vs 68.35%).

Bio-C Sealer and Prime MTA Bioceramic demonstrated significant cytotoxicity at high extract concentrations with acceptable biocompatibility at clinically relevant dilute concentrations. Bio-C Sealer exhibited superior cytocompatibility at the 25% concentration and a higher IC₅₀ value, indicating better overall cytocompatibility. The comparatively favourable cytocompatibility profile of Bio‑C Sealer at intermediate concentrations suggests that material selection may be influenced by its reduced cytotoxic potential, particularly in scenarios where periapical tissue contact is likely. These findings highlight the importance of considering biological performance alongside physicochemical properties when choosing endodontic sealers.