Effect of Bleaching on Dental Hard Tissues: A Raman and IR Spectroscopic Study

The effect of two bleaching materials on dental enamel was studied by vibrational spectroscopy. Human molar enamel sections parallel to the dentin-enamel junction were one-side polished and treated with bleaching agents containing 38% hydrogen peroxide (Opalescence Xtra Boost) or 20% carbamide peroxide (Opalescence PF 20%). Then the crystalline structure and molecular inclusions of the bleached samples were analyzed by Raman scattering and attenuated total reflectance infrared spectroscopy. No spectral difference was observed between the unbleached enamel and that bleached with the two different agents, which indicates no significant occurrence of structural or chemical changes in enamel apatite due to bleaching.