Cytocompatibility, bioactive potential and antimicrobial activity of an experimental calcium silicate-based endodontic sealer

Aim: To evaluate the cytocompatibility, bioactive potential, antimicrobial and antibiofilm activities of an experimental calcium silicate-based endodontic sealer, in comparison with TotalFill BC Sealer and AH Plus. Methodology: Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of the Saos-2 cells to the sealer extracts (1 : 2, 1 : 4, 1 : 8, 1 : 16 and 1 : 32 dilutions) for 24 h. The sealers were manipulated and placed in 12-well culture plates and exposed to ultraviolet light; then, 5 mL of DMEM without serum was added. Cell bioactivity was evaluated by alkaline phosphatase activity (ALP) and Alizarin red staining (ARS). Antimicrobial and antibiofilm activities were evaluated by direct contact test (DCT) on planktonic cells (DCTPC) and modified DCT on biofilm formed in bovine dentine blocks (MDCT). MTT, NR and ALP data were analysed by two-way anova and Bonferroni tests; ARS data by anova and Tukey's tests; and the microbiological data by Kruskal–Wallis and Dunn tests (α = 0.05). Results: The experimental sealer, TotalFill BC and AH Plus were not cytotoxic to Saos-2, in comparison with the negative control (P > 0.05). Greater ALP was observed after 7 days of exposure of Saos-2 to AH Plus and the experimental sealer (P < 0.05) when compared to the control. Significantly greater mineralized nodule production was observed for TotalFill BC and the experimental sealer (P < 0.05). In DCTPC, the experimental sealer and TotalFill BC were associated with a significantly greater reduction of E. faecalis (P < 0.05) and eliminated C. albicans. In MDCT, the experimental sealer and TotalFill BC had significantly greater antibiofilm efficacy (P < 0.05). Conclusions: The experimental calcium silicate-based sealer was cytocompatible, bioactive, antimicrobial against E. faecalis and C. albicans and effective against E. faecalis biofilms, with potential for use in root canal treatment.