Solubility and pH Value of 3 Different Root Canal Sealers: A Long-term Investigation.

Introduction: The aim of this study was to compare the solubility and the change in pH of a tricalcium silicate-containing sealer (BioRoot RCS [BR]), a mineral trioxide aggregate-containing sealer (MTA Fillapex [MTA]), and an epoxy resin-based sealer (AH Plus [AH]) during a longer period of time.
Methods: The solubility test was carried out in accordance with ISO6876:2012. Three hundred eighty sealer samples (n = 10 per group) were stored for 6 months in double distilled water (AD) or phosphate-buffered saline (PBS). The solubility was determined on the basis of the mass difference in percent. The pH measurement was carried out on the basis of the experimental setup of the solubility test with the aid of an electrode pH meter. The results were evaluated for significance by using analysis of variance, Student-Newman-Keuls, and t test (P < .05).
Results: The highest solubility was found for MTA in AD (4.65% ± 1.17%), followed by BR in AD (3.88% ± 0.42%) (P < .05). Also in PBS, MTA (3.24% ± 0.7%) showed a higher solubility than BR (1.78% ± 0.5%) (P < .05). AH was virtually insoluble during the entire period (0.5% ± 0.5%) (P < .05). The pH decreased continuously over time for all samples. After 6 months, BR showed the highest pH in AD (pH 10.3), followed by MTA in AD (pH 8.8), BR in PBS (pH 7.5), AH in PBS (pH 7.3), MTA in PBS (pH 7.2), and AH in AD (pH 6.3).
Conclusions: The solubility of MTA was significantly increased compared with BR and AH. Storage in PBS significantly reduced solubility of MTA and BR. BR showed a higher pH in both AD and PBS than MTA in AD and PBS. AH did not cause any significant pH change.
(Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)