Efficacy of laser application in dental bleaching: A randomized clinical controlled trial.

PURPOSE: To evaluate the bleaching efficacy of laser application with chemical treatment compared to chemical treatment alone. METHODS: This was a randomized controlled trial (RCT), single blind (evaluator), in 24 patients randomized into two groups: Laser and chemical intervention (12) or chemical intervention alone without laser (12). The commercial products used were Whiteness HP 35% hydrogen peroxide gel and the Whitening Laser II of DCM equipment. The color was measured with a spectrophotometer before, immediately and 3 days after the bleaching procedure. The trial outcome measures were obtained using the Vita EasyShade spectrophotometer and the International CIELCh system. To establish differences before vs. after treatments and between groups, the T test and chi(2) tests were applied. The data was statistically analyzed with Student's T-test (P </= 0.05). RESULTS: After applying the delta formula to measure the change in color, both groups gave clinically significant results before vs. after bleaching procedures ( P </= 0.05). The deltas for luminosity, chroma, and hue all showed significant improvements for baseline to 15 minutes post treatment (P </= 0.05), baseline to 3 days post treatment (P </= 0.05), but not for 15 minutes to 3 days post treatment (P >/= 0.05). When comparing between groups applying T-test, no statistically significant differences were found (P >/= 0.05) for all three deltas. When comparing sensitivity after bleaching, no differences were found between groups (P >/= 0.05). CLINICAL SIGNIFICANCE: The use of laser during bleaching treatment did not improve the results compared to not using laser.