This study was designed to assess the impact of Chitosan-acetate as final root canal irrigant on bond strength of resin-based sealer to radicular dentin.
Materials and Methods: Forty extracted human lower premolars with single roots and canals were prepared with ProTaper Universal rotary files till size F4. The samples were dispensed into 3 experimental groups according to the final rinse used and control group (10 samples each); Group I: irrigated with 0.2% chitosan acetate, Group II:17% EDTA, Group III: distilled water and control group (IV): saline. The samples were obturated by cold lateral compaction technique using AH plus sealer. Samples were sectioned into three sections (each 2 mm-thickness) from coronal, middle and apical thirds of each sample. The push out bond strength test was performed using universal testing machine. Three sections from each group were split longitudinally in buccolingual direction where the sealer/dentin interface and the sealer penetration inside the dentinal tubules was evaluated using scanning electron microscope (SEM). Results: Regarding the coronal and middle levels, there was no statistical significant difference among the tested groups. However, at the apical level, there was a statistical significant difference among the tested groups. SEM observation revealed minimal sealer penetration in group I at the apical level, while in group II, there was minimal sealer penetration at the coronal and middle levels. Regarding group III, there was minimal sealer penetration at middle level, while in control group (IV), there was no sealer penetration. Conclusion: The effect of 0.2% Chitosan acetate on the push out bond strength of AH Plus sealer was comparable to that of 17% EDTA when used as a final rinse. AH Plus sealer showed better adhesion to the dentin in the presence of smear layer especially at the apical third.