Effect of light on 3.5% hydrogen peroxide containing titanium dioxide

Objectives: This study investigated the effects of a bleaching agent with 3.5% hydrogen peroxide containing titanium dioxide on tooth color, and the influences of various lights sources on the performance of the bleaching agent. Methods: Pyrenees; (Mitsubishi Gas Chemical Company, Inc.) was used as the bleaching agent. The tooth color was measured with an SE2000 spectral color-difference meter (Nippon Denshoku) and evaluated with a CIE L*a*b* color system. The light source experiment was conducted using hematoporphyrin-dyed paper and three different light sources: Hyperlightel (Kuraray Medical INC.), Optilux 501 (Demetron, USA), and Pencure (Morita Inc.). The largest color change in the light source experiment was obtained in the samples irradiated by Hyperlightel. The smallest color change was obtained in the samples irradiated by Pencure. We next examined the effect of the bleaching on extracted human teeth using irradiation by Hyperlightel. Color measurements were taken before the bleaching treatment (L*0, a*0, b*0), and at 1 minute (L*1, a*1, b*1), 5 minutes (L*5, a*5, b*5), and 10 minutes (L*10, a*10, b*10) after the treatment. Results: The L*5 and L*10 levels were significantly higher than the L*0 level. The a* levels gradually increased, but did not rise significantly above the pre-treatment levels. The b*1, b*5, and b*10 levels were significantly lower than the b*0 level. On average, ΔE*ab1, ΔE*ab5, and ΔE*ab10 were 3.57 (SDą1.45), 5.44 (SDą1.60), and 7.50 (SDą1.88), respectively. These levels confirm the very high effects of the bleaching. Conclusions: Based on these results, we concluded that Hyperlightel had a higher bleaching effect than the other light sources, when used in combination the bleaching agent Pyrenees;. Pyrenees; was also found to have a high potential as bleach.