Correlation of Bond Strength and Dentinal Tubule Penetration Evaluation of Four Different Endodontic Sealers: AH Plus, MTA Fillapex, Endoseal MTA, and Endoseal TCS (Maruchi): An In Vitro Study.

Background: The sealer's penetration into dentinal tubules creates a physical barrier that entombs any remaining bacteria and increases the surface contact with the root canal walls. This study aimed to evaluate the dentinal tubule penetration and push-out bond strength of four sealers and to assess the correlation between penetration depth and bond strength. Methods: In this in vitro study, 40 human single-rooted anterior teeth were divided into four groups based on the sealer type and obturated using the single cone technique. Three slices of 1 ± 0.1 mm thickness were then prepared from each tooth at three regions-coronal, middle, and apical thirds-perpendicular to the longitudinal axis of the root. The depth and percentage of sealer penetration into the dentinal tubules were measured using confocal laser scanning microscopy (CLSM) on the prepared slices. To assess the bond strength of the sealers to dentin walls, a push-out bond strength test was performed using a universal testing machine. Data were analyzed using SPSS software through ANOVA, Tukey post hoc and Pearson's correlation tests. A Results: Statistically significant differences were observed in the extent and percentage of penetration, and the push-out bond strength of the studied sealers ( Conclusion: Calcium silicate-based sealers (Endoseal MTA and Endoseal TCS) achieved the greatest penetration, whereas AH Plus demonstrated the highest bond strength. The positive correlations observed suggest that dentinal tubule penetration may contribute to stronger bonding for specific sealers.