Effect of sodium and calcium hypochlorite with or without surfactant on the adhesion of epoxy resin-based endodontic sealer

Aim: To evaluate the effect of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2] in the presence or absence of surfactant benzalkonium chloride (BAK) on the bond strength of an epoxy resin-based sealer to root dentin. Methods: Fifty decoronated permanent human maxillary lateral incisors, with a single main canal and complete root development, were divided into 5 groups (n=10) according to the irrigant: 0.9% sodium chloride (NaCl), (control); 2.5% NaOCl; 2.5% NaOCl + 0.008% BAK; 2.5%Ca(OCl)2; and 2.5% Ca(OCl)2 + 0.008% BAK. Irrigation was performed using the syringe and needle. The root canal was prepared with 40.06 nickel-titanium instruments, under irrigation with 20 mL of the solution corresponding. Roots were filled using the single cone technique with gutta-percha and epoxy resin-based sealer. A slice from each third was obtained and subjected to the push-out test by applying an apical-coronal force until failure. Data were analyzed by post-hoc pairwise comparisons were performed using the Kruskal-Wallis test adjusted using the Bonferroni method (α = 0.05). Results: The groups treated with 2.5% NaOCl and 2.5% Ca(OCl)2 showed bond strength similar to the control group (p > 0.05). The use of an additional 0.008% of BAK was able to increase the bond strength after the use of 2.5% Ca(OCl)2 (p < 0.05) and did not change the bond strength after the use of 2.5% NaOCl (p > 0.05). Conclusions: The NaOCl and Ca(OCl)2 exhibited comparable bond strength values. Nevertheless, when the surfactant BAK was addition into both solutions, only Ca(OCl)2 demonstrated an increase in adhesion.