Effect of sodium hypochorite gel on shear bond strength of one-bottle adhesive systems

The aim of this study was to determine the effect of 10% NaOCl-gel on the dentin shear bond strengths (SBS) of three hydrophilic adhesive systems. One-hundred and twenty bovine incisors were mounted, polished with 320 to 600 - grit Al2O3 paper and randomly divided in 6 groups (n=15): G1 - Single Bond applied according to manufacturer's instructions; G2 - 10% NaOCl gel + Single Bond; G3 - Prime & Bond 2.1 used according to manufacturer's instructions; G4- 10% NaOClgel + Prime & Bond 2.1; G5 - Gluma One Bond used according manufacturer's instructions; G6- 10% NaOCl-gel + Gluma One Bond. In all groups, the dentin was etched, washed and lightly dried. After acid conditioning, groups 2, 4 and 6 received one drop of 10% NaOClgel, applied with a dwell time of 60 seconds, washed and blot dried. After the adhesive systems were applied and light-cured, a restorative composite resin was inserted in a teflon bipartite matrix and cured. The SBS were measured in a universal test machine at a crosshead speed of 0.5mm/min. The mean values were analyzed by twoway ANOVA and Tukey's tests (± £0.01). The SBS values (expressed in decreasing order, MPa ± SD) were as follows: G6=14.71 ± 4.38; G1=14.26 ± 3.95; G3=12.94 ± 5.20; G2= 12.84± 5.06; G4=10.24± 2.04; G5=10.14 ± 2.77. Conclusion: Collagen removal significantly increased the SBS of Gluma One Bond, but did not affect the SBS values of the other adhesives. The influence of 10% NaOCl gel in bond strength values may be dependent on the adhesive systems applied.