Influence of sodium hypochlorite and EDTA on the microtensile bond strength of a self-etching adhesive system

Chemical substances used during biomechanical preparation of root canals can alter the composition of dentin surface and affect the interaction with restorative materials. objective: the purpose of this study was to evaluate the microtensile bond strength (μtbs) of a self-etching adhesive system to dentin irrigated with sodium hypochlorite (naocl) and ethylenediaminetetraacetic acid (edta). material and methods: thirty human third molars were sectioned 3 mm below the occlusal surface,polished with 600- to 1200-grit silicon carbide papers,and randomly divided into 3 groups: g1 (control): no irrigating solution; g2: 1% naocl; and g3: 1% naocl followed by the application of 17% edta. the specimens received the self-etching adhesive system (xeno iii - dentsply),restored with microhybrid composite resin (z250 - 3m espe),sectioned and trimmed to create 4 hourglass-shaped slabs of each tooth. the slabs were tested in microtensile strength in a universal testing machine (emic dl 2000) at a crosshead speed of 0.5 mm/min until fracture. the results were analyzed statistically by anova and newman-keuls test. results: mean μtbs values and standard deviations in mpa were: g1 = 11.89 ± 4.22; g2 = 19.41 ± 5.32; g3 = 11.34 ± 4.73. 1% naocl increased the adhesive resistance significantly (p<0.001/ f=22.5763). the application of 1% naocl/17% edta resulted in statistically similar μtbs to the control group. conclusions: none of the irrigants affected negatively the μtbs of xeno iii to dentin. the use of 1% naocl alone resulted in higher bond strength than the other treatments. the combination of 1% naocl and 17% edta produced similar bond strength to that of untreated dentin.