Residual Effect of Sodium Hypochlorite on Pulp Chamber Dentin Adhesion

Aim: This study has evaluated the residual effect of NaOCl on resin-pulp chamber dentin bond strength after 7 and 14 days, using a three-step etch-and-rinse adhesive system.  Methodology: Forty pulp chamber dentin from bovine incisors crowns were randomly allocated to one of the following groups: G1, immersion in 0.9% saline solution for 30 minutes (control); G2, immersion in 5.25% NaOCl for 30 minutes; G3, immersion in 5.25% NaOCl for 30 minutes and stored for 7 days; and G4, immersion in 5.25% NaOCl for 30 minutes and stored for 14 days. After restoration, the dentin/resin interface was tested by microtensile bond strength and failure mode was analyzed by Scanning Electron Microscopy. Data were analyzed by ANOVA followed by Tukey.  Results: G1 had higher bond strength than the rest of the groups. There were no statistically significant differences among G2, G3, and G4 (p>0.05).  Conclusions: The adverse effect of NaOCl on bond strength persisted even after 14 days after exposure.