In-Office Power Bleaching: Light or No Light?

Purpose: In-office power bleaching using high concentration hydrogen-peroxide has lately become very popular; however, controversy still remains about the benefits of using auxiliary light activation. This study compared 4 in-office bleaching systems using different activating lights (high-intensity blue light, LED, ultra-violet and conventional halogen) and determined whether the use of lights enhanced tooth whitening vs. bleaching gels alone. Methods: Thirty-two extracted intact human molars were used in this study, and were divided randomly into four groups (N=8). Each group was assigned to one of four in-office bleaching systems: Beyond (Beyond Technology Corp), LumaCool (LumaLite Inc), Zoom2 (Discus Dental Inc) and Opalescence Boost (Ultradent Products Inc). Teeth were sectioned mesiodistally, producing 16 specimens in each group. The shade of the outer enamel surface of each specimen was determined by visual comparison to a 3D Master shadeguide (Vita Zahnfabrik). In each group, the specimens were divided into two subgroups, where one half of the tooth was bleached as recommended by the manufacturer with light activation and the other half with the bleaching gel alone. The specimen's color was evaluated immediately after bleaching and two weeks after immersion in distilled water at 37oC. Data was statistically-analyzed using Kruskal Wallis and Mann Whitney U tests. Results: All systems produced a significant tooth color change. Opalescence Boost produced most significant color change both immediately and after 2 weeks (p<.004); while LumaCool group showed the least color change. In all groups, the use of light did not significantly increase the whitening effects, except in the Beyond group immediately after (p=.04), and in the Zoom2 group 2 weeks after bleaching (p=.04). Conclusions: Opalescence Boost resulted in highest tooth color change even when no light activation was applied. Acknowledgments: Egyptian Ministry of Higher Education, Beyond Technology Corp, LumaLite Inc, Ultradent Products Inc.