Interproximal enamel reduction (orthodontic stripping) leaves surface-roughness that encourages plaque adherence. Sealants and fluoride products have been recommended to avoid possible detrimental effects. The objective of this study was to qualitatively evaluate, by means of scanning electron microscopy (SEM), the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on stripped enamel morphology after exposure to an acid solution. 15 extracted lower incisors underwent stripping with metal strips (Horico, 80 microm) by 1 operator. Mesial and distal surfaces were sectioned into 30 samples (22 stripped; 8 unstripped) and assigned to 2 groups: Group A (2 stripped; 2 unstripped) served as control; in Group B (20 stripped; 6 unstripped) tooth mousse containing CPP-ACP was tested. For 8 days, teeth were placed in acid lactic solution for 2h three times a day (from 9a.m. to 9p.m.) with 2h water preservation in between. After each demineralizing bath, samples of group B were coated with CPP-ACP for 5 min before immersion into water. In Group A, stripped samples exhibited greater demineralization compared to unstripped. In Group B, CPP-ACP reduced enamel dissolution on both intact and abraded samples compared to Group A. Injuries to enamel morphology caused by stripping might predispose to greater demineralization in the event of exposure to acid environment. Topical applications of CPP-ACP could be effective in promoting enamel remineralization after interdental stripping.