Effect of moisture and pH on setting time and microhardness of three premixed calcium silicate-based root canal sealers: an in vitro experimental study.

Abstract

Objectives: The study aimed to investigate how environmental conditions impact the setting time and microhardness of premixed calcium silicate-based sealers.

Methods: The setting time and microhardness of three sealers (Endoseal MTA [MARUCHI], One-Fil [MEDICLUS], and Well-Root ST [VERICOM]) were evaluated under four environmental conditions: unsoaked, distilled water-soaked, phosphate-buffered saline-soaked, and pH 5-soaked gypsum molds (n = 12/group/condition). The setting time was measured with Gilmore needles, and microhardness was assessed using a Vickers tester after 3 days. Welch's analysis of variance and Games-Howell post hoc tests were used for statistical analysis.

Results: The sealer type and environmental conditions significantly influenced setting time and microhardness (p < 0.001). The initial and final setting times were the shortest in the unsoaked samples. For Endoseal MTA and One-Fil, the unsoaked condition exhibited significantly shorter setting times than the soaked conditions. Well-Root ST exhibited significantly longer setting times in acidic conditions. Surface microhardness was highest in the unsoaked group (p < 0.001). Among the soaked groups, the phosphate-buffered saline-soaked group had the lowest hardness for Endoseal MTA, whereas the pH 5-soaked group exhibited the lowest hardness for One-Fil and Well-Root ST. Endoseal MTA consistently demonstrated a lower microhardness than the other sealers (p < 0.001).

Conclusions: Moisture, pH, and solution chemistry influenced the setting time and microhardness of premixed calcium silicate sealers. Although acidic conditions generally prolong the setting time and reduce hardness, the effects vary based on the sealers used and the setting environment.