Introduction: Previously published studies report a prevalence ranging from 35.9% to 58.7% of the general population with at least one impacted wisdom tooth. Surgical extraction of wisdom teeth is the procedure most often associated with postoperative complications, such as pain, swelling, trismus, and oral discomfort during the first postoperative days. These complications arise from an inflammatory response, which is a direct and immediate consequence of the surgical intervention and can limit the patients' daily functions in the recovery phase and compromise their quality of life. Several methods have been used to control postoperative morbidity related to wisdom tooth extraction, including administration of proteolytic enzymes, tube drains, cryotherapy, anti-inflammatory and analgesic drugs and low level laser therapy.

Objectives: To test whether the use of low power laser can improve post-operative pain, swelling and healing of the surgical wound.

Material and methods: A double-centre, randomised, split-mouth, double-centre clinical study will be carried out in 38 patients per centre, totalling 76 patients and 152 wisdom teeth, who will undergo surgery for the extraction of the lower third molars. The necessary data for the study will be taken on the days of the consultation for surgery planning, on the day of surgery, by the patient on each post-operative day and on the 7th post-operative day (at the time of suture removal ).

Inclusion Criteria:

• Patients who require extraction of the two lower wisdom teeth due to previous infection or pain, orthodontics or crowding, caries and who have a similar degree of difficulty according to the Pell and Gregory/Winter classifications.
• Patients must have the capacity to understand and decide at the time of voluntarily signing the informed consent before any intervention related to the study is performed.
• Patients who, after being informed about the aims and procedures of the research, agree and sign the informed consent form. Patients must be willing and able to adhere to the study in order to complete the necessary visits.

Exclusion Criteria:

• Patients with uncontrolled systemic disease (ASA ≥ III).
• Patients with severe periodontal disease or acute pericoronitis.
• Smokers of more than 5 cigarettes per day.
• Pregnant and lactating women, as the effect of laser therapy in this population has not been studied, its use is contraindicated.

The investigators will anonymize and categorize the clinical data of the patients to share the information with the other researchers of the group.

One side the laser off will be applied, on the other side, the laser on will be applied,