Effective use of traditional composite resins to attach orthodontic appliances to an impacted tooth requires isolation of the enamel surface during bonding, which can be difficult due to limited access and the presence of contaminates. Resin-modified glass-ionomer cements (RMGIC) have been shown to have the ability to bond to contaminated enamel surfaces. The purpose of this study was to evaluate the effect of two common contaminates experienced in this situation (blood and Hemodent) on the mean shear bond strength of an orthodontic button applied with light-cured RMGIC to an intact enamel surface.