Patients will receive 3 applications of low intensity light directly in the region of the three pairs of salivary glands already described. The ArGaAl diode laser, DMC 808nm 4J/point equipment will be used. The parameters that will be used are: Laser Diode ArGaAl, DMC, 808nm, 4J per point, continuously and in contact with the irradiated surface, resulting in irradiance of 3571 mW/cm2, distributed as follows: 6 points in each parotid, 2 points in each sublingual (external) and two in each submandibular (internal), totaling 16 extra oral and 4 intra oral, totaling 20 points. The exposure time will be 40s per point, corresponding to 800s per session and 3600s at the end of the four treatment sessions. The radiant exposure will be 142J/cm2. The first application will be after the stimulated collection of saliva and the following applications will be given once a week for another 2 weeks.

The placebo group will have a simulation of application of the laser, following the same technique as the active group, but with the device turned off. Because it is an infrared light, it is invisible and this will not induce the patient to notice that the device is turned off.

The parameters are: Laser Diode ArGaAl, DMC, 808nm, 4J per point, continuously and in contact with the irradiated surface, resulting in irradiance of 3571 mW/cm2, distributed as follows: 6 points in each parotid, 2 points in each sublingual (external) and two in each submandibular (internal), totaling 16 extra oral and 4 intra oral, totaling 20 points. The exposure time will be 40s per point, corresponding to 800s per session and 3600s at the end of the four treatment sessions. The radiant exposure will be 142J/cm2.

The patient will be instructed to keep the head forward allowing all saliva to passively pass through the collection tube, resting on the lower lip, for five minutes. In the last second, the patient will be instructed to spit out all the accumulated saliva in the collection tube. The amount of saliva and foam will be evaluated and properly recorded. Then, the dimethicone (removal of the air bubbles) will be used to obtain the final result. At the end of the photobiomodulation sessions a sample of saliva will be collected to be compared to the initial sample. The measurement will be made as follows: milliliters of saliva produced per minute. For stimulate sialometry, a sialogogue will be used. The quantity will be classified as follows: Production of normal saliva: 1.5 to 3.0 ml/minute; Light hyposalivation: from 1.05 to 1.45 ml/minute; Moderate hyposalivation: 0.55 to 1.0 ml/minute; Severe hyposalivation: from 0.05 to 0.50 ml/minute; Sialorrhea: above 3.0 ml/min.