This in vitro study aimed to qualitatively evaluate the effect of different remineralizing agents on the enamel pattern, after exposure to an acid solution. Fifteen human sound extracted third molars were collected and randomly allocated into the following five groups: Control Group (CG), without treatment; Negative Group (NG), treated with lactic acid solution; Mousse Group (MG), treated using a mousse of casein phosphopeptide (CPP) and amorphous calcium phosphate (ACP), associated with 0,33% sodium monofluorophosphate; Biosmalto Group (BG), treated with a dentifrice containing amorphous calcium phosphate functionalized with fluorine and carbonate-coated with citrate; Duraphat Group (DG), treated with a 5% sodium fluoride varnish. While CG remained immersed in chloramine solution for the entire period of the study, all the other groups were immersed in lactic acid for 2 hours and then subjected to the appropriate treatment for additional 2 hours, repeating the protocol 3 times a day, for 8 days. Finally, all samples were examined by Scanning Electron Microscope (SEM). SEM micrographs showed that CG had the typical morphological features of sound enamel, whereas NG presented superficial irregularities with early pattern of demineralization, characterized by apparent destruction of enamel prism cores. MG showed intact enamel prismatic arrangement and slight interprismatic dissolution, while BG and DG presented not defined margins of enamel prims and partial loss of interprismatic substance, being more pronounced in DG. Qualitative SEM evaluations demonstrate that topical applications of CPP+ACP associated with sodium monofluorophosphate could represent the most effective protocol for re-establishing the intact enamel structure, given acid environment.