Effect of the simulated body fluid containing bleaching agent on the hypersensitivity and surface microhardness of the tooth

In this study, the whitening effect of simulated body fluid (SBF) and side effects of a hydrogen peroxide (H₂O₂) as the bleaching treatment of tooth enamel surfaces was investigated. H₂O₂ solution of 25% and 30% was prepared by diluting the commercially available 35% H₂O₂ solution with either distilled water (DW) or SBF of 1×, 3×, and 5× concentrations. These diluted H ₂O₂ solutions were applied to the dental enamel surface of eighty human premolars for 15 min, followed by rinsing with DW. The procedure was repeated 4 times. The changes in color and surface microhardness before and after the bleaching procedure were recorded. The enamel surfaces of bleached teeth were examined with SEM. The results indicated that the brightness and microhardness of the tooth surface increased after bleaching with the SBF diluted agent compared to teeth treated with the DW diluted agent. These results might be due to the deposition of bone-like apatite that was observed with SEM. This bone-like apatite fills the area of roughness and holes in the enamel surfaces that were caused by bleaching, and created smoother and harder enamel surfaces. The result of this study suggested that a bleaching agent comprised of hydrogen peroxide and SBF would prevent the destructive side effects of bleaching and increase surface microhardness as well as having a whitening effect.