Effect of immersion in distilled water or phosphate-buffered saline on the solubility, volumetric change and presence of voids within new calcium silicate-based root canal sealers.

AIM: To assess the effect of immersion in distilled water or phosphate-buffered saline (PBS) on the solubility, volumetric change and presence of voids of calcium silicate-based root canal sealers (TotalFill BC, Sealer Plus BC and Bio-C), in comparison with the gold standard epoxy resin-based sealer (AH Plus). METHODOLOGY: All properties were evaluated after immersion in distilled water or PBS. Solubility was determined by the percentage of mass loss, whereas volumetric change and presence of voids were evaluated by micro-computed tomography, after 7 days of immersion. The volumetric change and percentage of voids between the baseline (after setting) and the experimental period were calculated. Statistical analysis was performed using one-way anova and Tukey's or Student's t-tests (α = 0.05). RESULTS: The calcium silicate-based sealers had significantly greater solubility and volumetric loss than AH Plus, after immersion in distilled water or PBS (P < 0.05). Bio-C had the greatest solubility (P < 0.05), followed by TotalFill BC and Sealer Plus BC, which were similar (P > 0.05). Regarding the volumetric change, AH Plus had a volume increase, with similar values in distilled water and PBS (P > 0.05). TotalFill BC, Sealer Plus BC and Bio-C had a similar volumetric change (P > 0.05). The calcium silicate-based materials had the greatest solubility and volume loss after immersion in distilled water (P < 0.05). There was no difference in the percentage of voids amongst the sealers, before and after immersion in distilled water or PBS (P > 0.05). CONCLUSIONS: TotalFill BC, Sealer Plus BC and Bio-C had significantly greater solubility and volumetric loss than AH Plus. Although storage in PBS significantly reduced the solubility and volumetric change of calcium silicate-based sealers, their solubility remained above that recommend by ISO 6876. All the sealers evaluated had low and similar voids, even after immersion in distilled water or PBS.

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.