effect of calcium hypochlorite and sodium hypochlorite as root canal irrigants on push-out bond strength of fiber post cemented with etch-and-rinse resin cement: an in vitro study

objectives: calcium hypochlorite (ch) has been recently used as a root canal irrigant. the aim of the present study was to compare the effect of ch and sodium hypochlorite (sh), as root canal irrigants, on the push-out bond strength of fiber posts cemented with an etch-and-rinse resin cement. materials and methods: in this experimental in-vitro study, 40 human anterior teeth with similar root lengths were randomly divided into five groups (n=8) according to the protocol of root canal irrigation as follows: group 1: saline (control); group 2: 2.5% sh; group 3: 5.25% sh; group 4: 2.5% ch; group 5: 5% ch. before post placement, the post space was irrigated using the same irrigation protocol, and after that, they were irrigated by distilled water. fiber posts were cemented with all-bond 3 bonding and dou-link universal cement. after thermocycling (1000 cycles, 5-55°c), a push-out test was performed, and data were analyzed using one-way analysis of variance and tukey s post-hoc test with spss version 23 (α=0.05). results: the highest and lowest mean bond strengths were detected in groups 2 and 5, respectively. there was no significant difference between group 1 and the sh groups (p 0.05), but the difference between group 1 and the ch groups was significant (p 0.001). there was a significant difference between sh groups and ch groups (p 0.001). conclusion: compared to sh, as a root canal irrigant, ch decreased the push-out bond strength of fiber posts cemented with an etch-and-rinse resin cement.