The purpose of this study is to investigate the stability of natural teeth whitening by analyzing the change on the tooth enamel surface and major mineral components, as well as tooth whitening using a natural material,
such as fruit juice. Only the buccal surfaces of 20 premolar teeth extracted were assigned to 5 groups (n=4). For Group 1, normal saline was applied; for Group 2, strawberry and baking soda were mixed at a ratio of 3:1; for Group 3, lemon and baking soda were mixed at a ratio of 3:1; and for Group 4, baking soda and water were mixed at a ratio of 3:1. About 1 ml of each material was applied on the enamel surface using a toothbrush. For Group 5, 5 mm whitening toothpaste was applied using a toothbrush. Color changes using the CIELAB, pH measurement using a pH meter, surface morphology using scanning electron microscopy (SEM), and mineral content using electromagnetic wave (X-ray) photoelectron spectrometer (XPS) were measured. The whitening effect was highest in the teeth applied with lemon compared to the whitening toothpaste. The pH value was lowest with the lemon application, which showed a distinctly rough surface and porosity. The Ca and P values were lowest in the tooth surface whitened with lemon. It was confirmed that tooth whitening with natural fruit juice increased the roughness of the tooth surface due to the acidic low pH. It also caused enamel demineralization and posed harm to the teeth.