Effect of Powder-to-Liquid Ratio on pH, Calcium Ion Release, and Solubility Behaviors of Endodontic Bioceramics: An In Vitro Study

This study investigated the physicochemical properties of three endodontic bioceramics: MTA Flow White (F), MTA Repair HP (HP), and Nishika Canal Sealer BG multi (BG). Disc-shaped samples were immersed in deionized water for 28 days to analyze pH, calcium ion concentration, mass change, and water sorption. Additionally, the effect of varying powder-to-liquid (or paste) ratios was investigated for F and BG. All samples exhibited mass loss due to surface degradation. Results showed that F exhibited the highest alkalinity (pH 10.8–11.3) and significantly greater calcium ion release (173.3–523.3 ppm) than other materials (p < 0.05). HP showed moderate alkalinity (pH 10.4–10.7) with lower calcium release (43.3–66.3 ppm), while BG exhibited the lowest alkalinity (pH 9.3–9.4). Regarding the effect of consistency, variations in the powder-to-liquid (or paste) ratio significantly influenced the physical stability of F and BG—notably shifting F from mass loss to mass gain—but did not significantly affect their pH or calcium ion release kinetics (p > 0.05). Consequently, both null hypotheses were rejected, as significant differences were observed among the materials, and consistency significantly affected mass change and water sorption but not alkalinity or ion release.