Effect of Photodynamic Therapy on the Pushout Bond Strength of Resin-Based and Calcium Silicate-Based Endodontic Sealers.

Introduction: This study aimed to assess the effect of photodynamic therapy (PDT) on the pushout bond strength (PBS) of resin-based and calcium silicate-based endodontic sealers. Methods: Forty single-canal teeth were assigned to four groups. After root canal preparation by the crown-down technique and smear layer removal, groups 1 and 2 served as the control group, and groups 3 and 4 underwent PDT by using a low-level diode laser as the light source and methylene blue as the photosensitizer (MB). The root canals in groups 1 and 3 were filled with AH26 sealer while the root canals in groups 2 and 4 were filled with Endoseal TCS. The samples were sectioned at 4, 8, and 12 mm from the apex tip (1mm thick slices). The PBS test was performed, and the mode of failure was determined in the coronal, middle, and apical thirds. The data were analyzed by the Kruskal-Wallis, Friedman, and Dunn tests. Results: No significant difference was noted in the PBS of resin-based and calcium silicate-based sealers in the apical, middle, or coronal thirds in the application of PDT ( P >0.05). The PBS of AH26 was significantly higher than that of Endoseal TCS ( P <0.05). Cohesive failure was the dominant mode of failure in the AH26 groups, while mixed failure was the dominant failure mode in the Endoseal TCS groups. Conclusion: PDT had no significant effect on the PBS of resin-based and calcium silicate-based sealers.