The aim of this randomized, longitudinal clinical study was to evaluate different protocols for dentin hypersensitivity treatment with low-power laser at different dosages, desensitizing agent, and associations, for a period of 6 months. After analysis of the inclusion and exclusion criteria of volunteer participants, those who present pain resulting from non-carious cervical lesions were selected. Twenty-seven patients participated in the study, and 55 lesions were recorded. The lesions were divided into five groups (n = 11), treated, and evaluated: G1: Gluma Desensitizer (Heraeus); G2: low-power laser (Photon Lase, DMC) at low dose (three vestibular points and one apical point of irradiation: 30 mW, 10 J/cm(2), 9 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between them; G3: low-power laser at high dose (application at one cervical and one apical point: 100 mW, 90 J/cm(2), 11 s per point with wavelength of 810 nm), three sessions were performed with an interval of 72 h between irradiations; G4: low-power laser at low dose + Gluma Desensitizer; and G5: low-power laser at high dose + Gluma Desensitizer, the level of sensitivity of each volunteer was evaluated with a visual analog scale of pain (VAS) with the use of air from a triple syringe and exploration with a probe after time intervals of 5 min, 1 week, and 1, 3, and 6 months after treatment. Data were collected and subjected to statistical analysis. Kolmogorov-Smirnov test was used to verify the distribution of the data, and nonparametric Kruskal-Wallis and Friedman tests were performed for comparison among the experimental groups and time intervals studied, respectively. Statistically significant differences between the studied time intervals (p < 0.05) were detected. From the difference in pain, it was observed that for both stimuli, the protocol with the Gluma desensitizing agent presented immediate effects of pain reduction. For low-level lasers, it was observed that there were distinct effects for the different doses; however, both were efficient in reducing pain up to the 6 months of clinical follow-up. Therefore, it could be concluded that all the desensitizing protocols were effective in reducing dentin hypersensitivity, but with different effects. The combination of protocols is an interesting alternative in the treatment of cervical dentin hypersensitivity.
