Two weeks before the start of the study, the volunteers will go through a wash out period, where they should only use oral care products donated by the researchers, which should be used until the end of the study. The oral hygiene kit will contain 1 toothbrush (Professional Lab Series, Colgate Palmolive), 1 toothpaste without desensitizing agent, but with fluorine (Elmex) and 1 dental floss (Colgate). Afterwards, this group will receive no treatment. Instead of the sealant, water will be used and the laser will remain with power 0W, that is, there will be no light emission, giving the group the characteristic of the control group, no treatment.

In this group, besides the instructions described in the control group, the teeth that will be sealed will be isolated. 35% phosphoric acid will be applied for 20 seconds and then it will be necessary to wash and dry the tooth surface. Apply a thin layer of PermaSeal (sealant) for 5 seconds to the tooth surface and light curing for 20 seconds.

In this group, besides the instructions described in the control group, volunteers will receive irradiation with AsGaAl laser, wavelength of 780 nm (Laser XT Therapy, DMC, São Carlos, SP) with fixed power of 100mW, energy density of 35 J/cm2 (considering a spot size of 0.028 cm2 of this equipment), the dose will be 1 J per point. The irradiation will be performed at a cervical, an apical point and another point exactly on the injury, totaling a dose of 3J. Treatment should be performed in 3 sessions with an ideal 72-hour interval between them.

Two weeks before the start of the study, the volunteers will go through a wash out period, where they should only use oral care products donated by the researchers, which should be used until the end of the study. The oral hygiene kit will contain 1 toothbrush (Professional Lab Series, Colgate Palmolive), 1 toothpaste without desensitizing agent, but with fluorine (Elmex) and 1 dental floss (Colgate).

Pain will be assessed with the visual analogue scale (Visual Analogue Scale - VAS), after stimulation with air from the triple syringe and an explorer probe.