Novel bleaching system using by titanium dioxide with hydrogen peroxide

Objectives:

Hydrogen peroxide (H₂O₂) in the form of carbamide peroxide is widely used for tooth bleaching, both in professionally and in self-administered products. Hydrogen peroxide is a highly reactive substance which can damage oral soft or hard tissues when present in high concentration and with exposures of prolonged duration. H₂O₂ was well known as reactive oxygen species (ROS). We also confirmed ROS generation from irradiation of the titanium dioxide (TiO₂). Therefore, in this study, we used for novel tooth bleaching the ROS generated with an irradiated TiO₂ with low concentration (0.3%) of H₂O₂.

Methods:

We detected ROS generated from a mixture, including H₂O₂ and irradiated TiO₂, using by ESR spin trapping technique. The clinical condition of a tooth bleaching agent was formulated by the results of ESR analysis. The deciduous teeth was treated with irradiated TiO₂/H₂O₂ system. The Lab color coordinate system was used for the evaluation of the effects of the bleaching. The color difference (DE*ab) was calculated from the value of obtained Lab values. The influence with bleach on the enamel surface was evaluated by using scanning electron microscopy (SEM).

Results:

We identified the generation of superoxide anion radical (O₂^•-) from irradiated TiO₂ with TiO₂/H₂O₂. O₂^•- production was increased in irradiation time-dependent manner. Both L and DE*ab value were increased by tooth bleaching using irradiated TiO₂/H₂O₂ system. At the SEM image, the alteration on the enamel surface was not recognized by the bleaching treatment.

Conclusions:

These results suggested that low concentration of TiO₂/H₂O₂ system would be more safety due to form O₂^•- but not hydroxyl radical as a risk factor for bleaching. Furthermore, we could be done tooth bleaching using low concentration of 0.3% H₂O₂. We will develop safe and anti-aging tooth bleaching system using irradiated TiO₂/H₂O₂ in the near future.