Evaluation of tooth color after bleaching with and without light-activation

Purpose: The use of different light sources as an adjunct to in-office bleaching has been questioned. Thus, the aim of this study was to evaluate the color changes of teeth after application of bleaching techniques with different products, with and without activation by a LED-laser system. Methods: Twenty-four bovine teeth surfaces were submitted to three bleaching techniques with two commercially available 35% hydrogen peroxide bleaching agents (n=8). The specimens were immersed in red wine for 48 h at 37°C and submitted to the bleaching techniques. Color changes were measured before and after staining as well as immediately after and 24 h after the bleaching treatments, with two different methods of color evaluation, software ScanWhite V1.1 and intra-oral spectrophotometer (Vita Easyshade). Data were analyzed by ANOVA and Kruskal-Wallis test. Results: The statistical analysis showed that there was no statistically significant difference at 5% of significance level between the different groups, independently of the evaluation time, evaluation methods or the use of LED-laser systems. Conclusion: The results suggested that the use of light in the bleaching techniques did not influence the color changes.