Souto-Maior JR, et al. - Researchers performed a systematic review and meta-analyses evaluating the efficacy of tooth color change and sensitivity of teeth following in-office bleaching with and without light gel activation in adult patients. They included only randomized clinical trials among adults that compared in-office bleaching with and without light activation with the same bleaching gel concentrations Outcomes suggested that for achieving esthetic clinical results, the use of light sources for in-office bleaching seemed to have no significance.