Effects of LED photobiomodulation on pain, oedema, trismus, and the quality of life following the extraction of the mandibular third molar: a randomized blinded clinical trial.

The extraction of the third molar is a frequent surgical procedure often associated with postoperative sequelae such as pain, oedema, and trismus, which can negatively impact patients' quality of life. This randomized, double-blind, placebo-controlled clinical trial aimed to evaluate the efficacy of low-level light-emitting diode (LED) photobiomodulation (660 nm, continuous wave) in reducing these sequelae after mandibular third molar surgery. Forty-two patients were allocated to an active LED group (n = 21) or a placebo group (n = 21). Pain (visual analogue scale), oedema (linear facial measurements), trismus (maximal mouth opening), analgesic consumption, and quality of life were assessed preoperatively and on postoperative days 2, 4, and 7. No statistically significant differences were observed between groups in facial oedema or quality of life. The LED group showed statistically significant improvements in mouth opening (day 2: P = 0.001; day 4: P = 0.01), pain scores (day 2: P = 0.001; day 4: P = 0.01), and analgesic consumption (day 2: P = 0.001; day 4: P = 0.01) compared with the placebo group. No significant differences were found on day 7 for any variable. LED photobiomodulation provided significant early benefits (days 2 and 4) in mouth opening, pain reduction, and decreased analgesic use after third molar surgery, without affecting oedema or quality of life. These findings support its use as a non-invasive adjuvant therapy for the management of acute postoperative symptoms.