Assessment of pH values of four calcium silicate-based sealers in different time intervals

AIM: To assess pH values of calcium silicate-based sealers in different time intervals. Methodology: Four calcium silicate-based sealers were included in the study: Endosequence BC, USA (BC), Bio C, Brazil (Bio C), BioRoot Flow, France (BRF), BioRoot RCS, France (BR) and control epoxy -based AH Plus, Germany (AH). Polyethylene tubes measuring 10 mm in height, 1.6 mm in diameter were filled with each sealer (n =5). Each specimen was placed in a flask containing 10 mL deionized water and stored at 37°C, 100% humidity. The pH assessment was performed after 1, 7, 14, 21 and 28 days of immersion. Prior to each measurement cycle, pH electrode was calibrated using two calibration solutions pH 7 and 10. Each measurement was done in triplicates and a mean value was calculated. After each measurement, the specimens were immersed in fresh deionized water and kept at 37 °C. Statistical analysis was performed using two-way ANOVA. Tukey’s post-hoc comparison test was conducted to test differences between sealers at each time point. The level of significance was set at alpha=0.05. Results: Calcium silicate-based sealers BC, Bio C, BRF and BR showed significantly higher pH values than AH in all time intervals (p < 0.001). All calcium silicate-based sealers exhibited similar pH values in all measured intervals. The pH values for these sealers varied from nearly 12 after 24 hours, to 7.5 after 28 days. The highest pH value was 11.95 and it was recorded in the first-time interval (after 1 day) for BRF. Conclusions (mandatory): Conclusions: All calcium silicate-based sealers exhibited and maintained high alkaline pH values through-out the 28-day time interval. The highest values at or above pH 10 were recorded in all calcium silicate-based sealers over the first 7 days.