Effect of powder particle size on hydration rates, permeability and antimicrobial properties of tricalcium silicate in root canals

This study investigated the impact of particle size refinement on the hydration rate, permeability, and antimicrobial properties of tricalcium silicate (C₃S) in root canal applications. Four C₃S pastes with varying particle sizes were prepared and evaluated. Hydration experiments indicated that finer particles accelerated the early hydration rate, though agglomeration effects influenced the long-term behavior. Permeability assessments using simulated body fluid and confocal laser scanning microscopy revealed that smaller particles achieved significantly greater penetration depth and area into dentinal tubules. Antimicrobial tests against Enterococcus faecalis demonstrated that the 0.4 μm C₃S group exhibited superior bactericidal efficacy, with a notable improvement in penetration and antibacterial activity compared to the 12.8 μm group. These findings suggest that particle size reduction enhances the functional performance of C₃S-based sealers in endodontic therapy.