OBJECTIVES: To determine in vitro the effects of 2 commercially available microabrasion compounds (Prema [Premiere Dental Products] and Opalustre [Ultradent]) on human enamel under standardized conditions after treatment periods of 10, 20, 30, and 40 seconds. Nonacidified pumice served as an abrasive control compound. METHOD AND MATERIALS: Mean substance loss was determined by measuring dissolved Ca2+ using atomic absorption spectrophotometry. Differences in the mean surface roughness were profilometrically assessed. These findings were completed with micromorphologic observations using SEM. In addition, color changes after microabrasion were evaluated using the CIE L*a*b* system. RESULTS: Opalustre caused the highest tooth substance loss, followed by the Prema compound and pumice, which showed a lesser substance-removal capacity. These findings were in concordance with the mean surface roughness difference measurements and micromorphologic analyses. Microabrasion did not cause any significant colorimetric changes. CONCLUSION: Microabrasion should be considered a microinvasive method, and clinical application should be used with caution to avoid excessive substance removal. Subsequent polishing appears crucial to maintain optimal esthetics and avoid surface alterations.