Correlations among Antibacterial Efficacy in Dentinal Tubules, pH, and Calcium Ion Release of 5 Premixed Calcium Silicate-based Sealers in a Novel ex vivo Model
He Liu, Chanchan Chen, Zhejun Wang, Ya Shen
Abstract
<h2>Abstract</h2><h3>Introduction</h3> To evaluate the antibacterial efficacy of five premixed calcium silicate-based sealers in infected dentinal tubules using a novel <i>ex vivo</i> model, and to investigate correlations among antibacterial efficacy, pH, and calcium ion release. <h3>Methods</h3> Forty human premolars with a single canal were selected and stored in 0.01% NaOCl solution at 4 °C. The teeth were sectioned to obtain 64 dentin blocks, which were sterilized and inoculated with <i>Enterococcus faecalis</i> for 3 weeks. Four infected blocks were analyzed using scanning electron microscopy. Sixty infected blocks were fitted into 3D-printed teeth and assigned to six groups based on the sealer used: Control, BIO-C SEALER ION<sup>+</sup> (BIOC<sup>+</sup>), EndoSequence BC Sealer HiFlow (HF), EndoSequence BC Sealer (BC), NeoSEALER Flo (NEO), and BioRoot Flow (BRF). Specimens were subsequently obturated using the single-cone technique. Antibacterial efficacy was evaluated at 1 and 4 weeks using viability staining and confocal laser scanning microscopy. Leachates from sealer discs were collected to analyze pH and calcium ion at day 1, 1 week, and 4 weeks. Statistical analysis was performed using one-way ANOVA, unpaired t-test, and Spearman's correlation (α = 0.05). <h3>Results</h3> At 1 and 4 weeks after obturation, no significant differences in antibacterial efficacy were observed among the sealer groups; all groups exhibited significantly higher antibacterial efficacy at 4 weeks compared to 1 week (<i>P</i> < .05). At day 1, 1 week, and 4 weeks, all sealers exhibited pH values above 11, with significant differences observed among them at each time point (<i>P</i> < .05). Calcium ion concentrations differed significantly among sealers at all time points (<i>P</i> < .05). HF, BC, and BRF showed higher pH values and calcium ion concentrations than BIOC<sup>+</sup> and NEO at all time points (<i>P</i>< .05). A strong positive correlation was found between pH values and calcium ion concentrations at all time points (<i>P</i> < .05). <h3>Conclusions</h3> The tested premixed calcium silicate-based sealers demonstrated similar antibacterial efficacy in dentinal tubules, despite variations in pH and calcium ion release.