OBJECTIVETo evaluate the effects of fluorid on morphology change in enamel and dentin during tooth bleaching.

METHODSThe study population consisted of twelve patients who required the extraction of first premolars for orthodontic reasons. Twelve participants were divided into three groups: bleaching with NaF-treated group, bleaching-treated group and control group. Immediately after bleaching treatment, all teeth were extracted and prepared for scanning electron microscope (SEM). Morphologic observations were carried out with SEM.

RESULTSIn the bleaching-treated group, mild demineralization was observed on the surface of enamel and collapse of collagen scaffold was also observed on the longitudinal section of dentine. The diameter of dentinal tubule was not uniform due to peritubular dentine was demineralized. In the bleaching with NaF-treated group, the demineralization of enamel and dentin were reduced and some diameter of dentinal tubule were smaller than bleaching-treated group.

CONCLUSIONFluoride can reduced the demineralization of enamel and dentine obviously, which may be applied as a therapeutic tool for sensitivity induced by tooth bleaching.