Setting time of calcium silicate-based sealers at different acidic pHs

Aim: To evaluate the effect of acidic pH levels on the setting of calcium silicate-based sealers, comparing them with an epoxy resin-based sealer.

Methodology: Bio-C Sealer (Angelus, Londrina, Brazil), EndoSequence BC Sealer (Brasseler, Savannah, USA), BioRoot RCS (Septodont, Saint Maur des Fosses, France), or AH Plus Jet (Dentsply DeTrey, Konstanz, Germany) were inserted into 2mm high plaster casts or 1mm high stainless-steel rings, both with a 10mm internal diameter, following ISO 6876-2012. Each sealer's 54 samples were exposed to gauze soaked in PBS 7.4 (control), acidified PBS (pHs 6.4, 5.4, and 4.4), or butyric acid buffer (pHs 6.4, 5.4, and 4.4) solutions. Six samples were used for each solution. The Gilmore needle was used to evaluate the setting periodically for 15 hours and then once a day after 24 hours. The results were analyzed using the repeated measures ANOVA statistical method (α= 5%).

Results: All sealers achieved setting within 24 hours. EndoSequence and BioRoot maintained their average setting time at all tested pH levels, with EndoSequence having the longest setting time and BioRoot the shortest, showing a significant difference between them (α=5%). Bio-C Sealer's setting time was affected at acidic pH levels, similar to EndoSequence BC Sealer when in contact with PBS 4.4 solution or butyric acid buffer solutions (p=1.000). AH Plus's setting time remained stable, except in the PBS pH 4.4 solution.

Conclusions: BioRoot and EndoSequence showed no change in setting time when exposed to acidic solutions. BioRoot demonstrated the shortest setting time across all pH levels.