One of the advancement in in-office bleaching techniques is the development of laser activating systems. One of this new systems is (Whitening Lase II DMC), this system is combination of infrared laser with LED in one light so will provide best result with less time and sensitivity. Lase II provided with three different bleaching agents, based on the concentration of hydrogen peroxide:(Lase PeroxideLite-15%, Lase Peroxide Sensy II - 25%, and Lase Peroxide Sensy II - 35%). Hydrogen peroxide concentration is one of the paramount factors contributing to the efficacy of bleaching. Improvement of discolored teeth may be affected by various concentrations of peroxide. Also surface roughness of tooth structure may follow bleaching process. Evaluation the effect of different peroxide concentration for both color changes and surface roughness within the same experiment is limited. In this study we try to clarify the relationship between color changes and surface roughness within the same experiment after bleaching with three different hydrogen peroxide concentrations.