OBJECTIVE To assess in vitro the effect of manual and powered toothbrushes on the bond strength of orthodontic brackets. METHODS Specimens of orthodontic brackets bonded to the surfaces of extracted teeth were exposed to one of two powered toothbrushes (Sonicare Elite, Braun Oral-B 3D Excel) or a manual toothbrush (Oral-B 35) for the equivalent of a 2-year exposure to brushing in the presence of toothpaste slurry. Control specimens underwent no brushing. For each treatment, 10 specimens were tested and evaluated. Shear bond strength of the orthodontic bracket to the tooth surface was assessed after exposure to simulated brushing. ANOVA was used to analyze the data. RESULTS No differences in orthodontic bracket bond strength were observed between any of the three treatments and the control. The evaluated toothbrushes did not adversely affect the in vitro bonding strength of orthodontic brackets, suggesting they are safe to use in orthodontic patients.