RESUMO
This study was designed to evaluate the effect of a final rinse with 0.2% chitosan solution on the adhesion in roots filled with gutta percha and an epoxy resin based sealer. Thirty extracted human maxillary canines selected to ensure specimen standardization were used in the study. After the coronal portion of each tooth was removed, the roots were instrumented and irrigated with 1% sodium hypochlorite (NaOCl). Roots were distributed into 3 groups according to the final rinsing solution (n = 10): 0.2% chitosan, 17% ethylenediaminetetraacetic acid (EDTA), or 1% NaOCl. The canals were irrigated with 5 mL of each solution for 5 minutes and then filled with gutta percha cones and the resin based sealer. Ten roots in each group were prepared, sectioned, and submitted to push-out testing. Data were analyzed with analysis of variance and Tukey test (P < 0.05). In the push-out test, final irrigation with chitosan (mean, 0.37 [SD, 0.12] MPa) or EDTA (0.38 [0.11] MPa) resulted in significantly greater bond strength of the sealer to the root canal (P < 0.05) than did irrigation with 1% NaOCl (0.13 [0.04] MPa). The cervical third had greater bond strength than the other thirds (P < 0.05). Adhesive failure was the most frequent type in all groups. A final rinse with 0.2% chitosan or 17% EDTA resulted in greater bond strength of root fillings to the root canal than did 1% NaOCl.