Evaluation of the pH, calcium ion release, and antibacterial effect of a premixed bioceramic endodontic sealer

Abstract

This study sought to compare a bioceramic sealer (TotalFill) and a calcium hydroxide (Ca[OH]2) sealer (Sealapex) in terms of their pH, calcium ion (Ca²⁺) release, and antibacterial effect against Enterococcus faecalis bacteria. For the pH and Ca²⁺ release tests, 20 polyethylene tubes (10 mm in height and 1 mm in internal diameter) were filled with the appropriate sealer (n = 10 per sealer), immersed in glass flasks each containing 10 mL of deionized water, and stored in an incubator at 37°C. The water was changed after 1, 7, 28, and 90 days. At each water change, the eluates were measured with an advanced electrochemistry meter to determine the pH and with a flame atomic absorption spectrometer to determine the Ca²⁺ release. The antibacterial effect was measured using the turbidimetry-based direct contact test in which the wells of a microtiter plate were coated with a thin, even layer of freshly prepared sealer (10 wells per sealer), which was allowed to set before application of a suspension of E faecalis. Control wells were obtained by placing an identical bacterial suspension in 10 uncoated wells. The optical density of the sealer and control groups was measured immediately and 1, 3, and 7 days after sealer preparation. Data were analyzed for normality with the Shapiro-Wilk and Kolmogorov-Smirnov tests. Two-way analysis of variance (ANOVA), Student t test, and 1-way ANOVA with Tukey post hoc tests were all utilized with a significance level of P < 0.05. TotalFill maintained significantly higher pH and Ca²⁺ release levels than Sealapex at all evaluation times (P < 0.05). Both sealers demonstrated significantly greater antibacterial effect (lower optical density) than the control group; however, TotalFill resulted in significantly lower optical density values than Sealapex (P < 0.05). TotalFill bioceramic sealer demonstrated superior Ca(OH)2-related properties compared to Sealapex Ca(OH)2 sealer.