Effects of light irradiation on bleaching by a 3.5% hydrogen peroxide solution containing titanium dioxide
✍ Scribed by T. Suemori; J. Kato; T. Nakazawa; G. Akashi; A. Igarashi; Y. Hirai; Y. Kumagai; H. Kurata
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 105 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1612-2011
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✦ Synopsis
A low-concentration hydrogen peroxide solution containing titanium dioxide as a photocatalyst has attracted attention as a safe office bleaching agent. In this study, the influence of different kinds of light on the bleaching effect of this agent was examined. The bleaching agent was applied to hematoporphyrin-stained paper strips that were then irradiated with a 405-nm diode laser (800 mW/cm^2^), a halogen lamp (720 mW/cm^2^), or an LED (835 mW/cm^2^) for 5 minutes. The color was measured spectrophotometrically before treatment and every 30 seconds thereafter, and the effects of bleaching on the strip were assessed using the CIE 1976 L
^*^ a^*^ b^*^ color coordinate system. Of the three different irradiation conditions, 405-nm laser irradiation gave the strongest bleaching effect with 3.5% hydrogen peroxide containing titanium dioxide. The laser provides strong irradiance at 405 nm, which corresponds to the absorption range of the bleaching agent, and consequently the largest effect was obtained.