The purpose of this trial is to evaluate the efficacy of photobiomodulation of the major salivary glands on salivary parameters in children with caries activity.

Dental caries represents one of the most prevalent diseases among children around the world. Saliva plays a preponderant role in the process of demineralization- remineralization of the dental surface. Patient salivary characteristics, such as flow rate, pH, and buffering capacity, provide relevant information about patient's risk for developing carious lesions. Photobiomodulation has shown promising results to improve salivary flow rate, as well as buffer capacity in the adult population. The purpose of this trial is to evaluate the efficacy of photobiomodulation of the major salivary glands on salivary parameters in children with caries activity.

Methods: This protocol details a randomized, double-blind, parallel-group, controlled trial evaluating salivary parameters through photobiomodulation in children. Seventy-eight 6- to 12-year-old participants will be randomly divided in two groups: 1) the photobiomodulation experimental group (G1) (n=39), 2) the photobiomodulationn placebo group (G2) (n=39). Infrared light will be applied in 16 intra and extraoral points and the placebo, respectively. The unstimulated salivary sample will be taken before and immediately after the application once a week, for three consecutive weeks. Salivary samples will be analyzed for flow rate, pH and buffering capacity. The primary outcomes are difference in salivary flow rates between the G1 and the G2. The secondary outcomes are difference in salivary pH and buffering capacity between the G1 and the G2 group.

nclusion criteria

• Individuals of both sexes, between 6 and 12 years old with mixed dentition.
• Participants diagnosed with the presence of at least one active caries lesion
• Good general health, without systemic or local diseases that affect salivary secretions.

Exclusion criteria

• Participants with severe active cavitated lesions with pulpal symptoms.
• Plans of the family nucleus to move for the duration of the study.
• Patients with a diagnosis of hyposalivation or xerostomia
• Presence of fixed appliances.
• Physical disability that interferes with oral or intellectual hygiene to answer the questionnaire.

Only the researcher responsible for applying the laser will know which treatment was assigned to each participant. The researcher responsible for data collection will be blinded to the type of treatment received. The participant will be blind. The treatment with the control group will simulate the laser in operation.