Methods: Ninety inferior bovine incisors freshly extracted were randomly divided into three groups of 30 each. Teeth from groups 1 and 2 were bleached with hydrogen peroxide, and bonded 24 hours and 7 days after this procedure, respectively, in group 3, control group, teeth were not bleached. After the bonding procedure all samples were stored for 24 hours in deionized water at 37o C and then tested in a shear mode on a testing machine and the ARI was evaluated.
Results: The KRUSKAL-WALLIS test revealed a statistically significant higher bond strength in group 2 (p<0,05) when compared with groups 1 and 3. There was no statiscally significant difference between mean bond strength in groups 1 and 3.
Conclusion: These in vitro study indicates that enamel bond strength is not affected by 35% peroxide hydrogen bleaching after 24 hours, but it increases after 7 days.