<b>Sealing Ability of Calcium Silicate–Based Sealers Under Different Moisture Conditions</b>

Background: A durable apical seal is essential for successful endodontic treatment because inadequate obturation may permit microleakage and reinfection. Calcium silicate–based sealers are hydrophilic hydraulic materials that require moisture for setting; however, the ideal intracanal moisture condition for optimal sealing remains uncertain. Objective: To evaluate the effect of different intracanal moisture conditions on the sealing ability of a calcium silicate–based root canal sealer. Methods: This in-vitro experimental study included 60 extracted permanent single-rooted human teeth with fully formed apices. After standardization of root length, canals were prepared using rotary nickel-titanium instruments and irrigated with 2.5% sodium hypochlorite, 17% EDTA, and distilled water. The specimens were randomly divided into three groups according to canal moisture condition before obturation: dry canal, slightly moist canal, and wet canal, with 20 teeth in each group. All canals were obturated using gutta-percha and a calcium silicate–based sealer with the single-cone technique. Samples were stored at 37°C and 100% humidity for seven days. Apical sealing ability was assessed using 2% methylene blue dye penetration for 48 hours, followed by longitudinal sectioning and stereomicroscopic evaluation at 20× magnification. Data were analyzed using one-way ANOVA, with significance set at p < 0.05. Results: The slightly moist canal group showed the lowest mean dye penetration at 0.75 ± 0.19 mm, followed by the dry canal group at 1.16 ± 0.24 mm. The wet canal group showed the highest mean dye penetration at 1.59 ± 0.25 mm. One-way ANOVA demonstrated a statistically significant difference among the three groups, indicating that intracanal moisture condition significantly affected apical leakage. Conclusion: Controlled residual moisture improved the sealing ability of the calcium silicate–based root canal sealer, whereas excessive moisture increased apical microleakage. A slightly moist canal environment may therefore be more favorable than complete dryness or visible wetness during obturation with hydraulic calcium silicate–based sealers.