Background Dentin hypersensitivity (DH) is defined as an exaggerated sensitivity of vital dentin exposed to thermal, chemical and tactile stimuli. This study aimed to evaluate, through a literature review, the applicability of high- and low-intensity lasers in the treatment of DH for the past 10 years, as well as its therapeutic potential. Material and Methods The electronic databases MEDLINE/PubMed and LILACS were searched using the descriptors (“Dentin Sensitivity” OR “Dentin Hypersensitivity”) AND (“Low-Level Therapy” OR Laser), for articles published between 2010 and 2020. Only randomized clinical trials with full-text and full case resolution were included. Results We found 187 articles in total, among which 61 were pre-selected and 10 included in this literature review. Conclusions Considering the found results and their possible limitations, high- and low-intensity lasers, associated or not with other therapies, have demonstrated beneficial effects in the treatment of DH, being considered a promising, safe, easy, and effective field of research, reducing pain sensitivity and preserving pulp vitality. Key words: Dentin sensitivity, dentistry, laser.

Background To evaluate the tooth enamel surface morphology after the action of 35% hydrogen peroxide with and without LED activation. Material and Methods 70 bovine incisors with an enamel surface of 4x4x3 mm were used, prepared for reading superficial microhardness and roughness. Specimens were randomly distributed and divided into 7 experimental groups (n = 10); G1 = artificial saliva; G2 = 35% HP - 2 sessions (3x15´); G3 = Phosphoric Acid + 35% HP - 3 sessions (3x15´); G4 = 35% HP - 2 sessions (3x15´) + blue LED; G5 = 35% HP - 2 sessions (3x15´) + green LED; G6 = 35% HP - 2 sessions (3x20´) + violet LED; G7 = Violet LED - 2 sessions (3x20´). The results were analyzed by the Anova, Wilcoxon, Dunnett and Tukey tests (α = 0.05). Results The G4 group showed a greater change in microhardness. Regarding roughness, the biggest mean difference between groups occurred in G2, G5 and G7. Optical microscopy showed a smooth enamel surface in groups G2, G5 and G7. Conclusions Changes in the enamel surface were observed in relation to microhardness, but without significant changes in roughness, where the LED (green and violet) resulted in a smooth surface. Key words: Tooth whitening, superficial morphology, light, photoradiatio.