Effects of hydrogen peroxide on human dentin structure

It has been hypothesized that hydrogen peroxide (H2O2) bleaching may cause destruction of dentin by a mechanism of protein oxidation. However, to our knowledge, there has been no direct chemical evidence to validate this viewpoint. To investigate the effects of H2O2 on the structure of human dentin, we used Fourier transform infrared spectroscopy (FTIR) and attenuated total reflection (ATR) spectroscopy. Human intact dentin specimens were treated either with 30% H2O2 or Hanks' balanced salt solution (HBSS). Significant differences were observed in ATR spectra parameters. Additionally, demineralized dentin specimens were also tested. They were completely dissolved in the H2O2, but remained intact in the 0.1 N HCl and HBSS. The results suggested that H2O2 attacked both the organic and mineral components of dentin. Destruction of the organic components was mainly because of the oxidizing ability of H2O2, while changes in the mineral components were probably due to its acidity.