Microstructural effect of a laser-activated bleaching agent containing titanium dioxide on human enamel

AIM: This study aimed to evaluate the effect of a laser-activated bleaching agent containing titanium dioxide (TiO(2)) nanoparticles on enamel roughness and hardness. MATERIALS AND METHODS: Twenty human premolars were randomized into two groups according to the bleaching treatments performed: HP – 35% hydrogen peroxide and HP + TiO(2) – 30% hydrogen peroxide containing TiO(2) light-activated by diode laser (980 nm). It was performed two bleaching sessions with an interval of 7 days. Microhardness and roughness of the enamel were assessed at three times: T0 – Before 1(st) appointment, T1 – after 2(nd) appointment, and T2–7 days after 2(nd) appointment. RESULTS: The HP + TiO(2) did not cause changes on enamel roughness and hardness and presented the same effects of the HP. CONCLUSIONS: Both bleaching agents showed no difference between them. Then, it is possible to conclude that both are viable for clinical use during in-office dental bleaching technique regarding the microstructural changes that they might cause.