Erika da Silva Mello, Anna Carolina Ratto Tempestini Horliana, Cícero Dayves da Silva Bezerra, Kristianne Porta Santos Fernandes, Luciana Toledo Costa Salviatto, Sandra Kalil Bussadori, Samuel Feliciano Pereira, Vanessa Dalapria, Regiane Silva de Sales, Alessandro Melo Deana
BACKGROUND: Postoperative pain, swelling, and functional limitations are common after mandibular third molar surgery, affecting recovery and quality of life. This randomized, double-blind clinical trial evaluated the effects of preemptive photobiomodulation therapy with infrared LED on postoperative pain, as well as edema and trismus. METHODS: Eighty healthy participants requiring lower third molar extraction were randomly assigned to a photobiomodulation group or a sham group. Nine patients from each group were excluded from the sample because they did not comply with the postoperative instructions. The treated group received photobiomodulation (850 nm, 100 mW, 24 J) 1 hour before surgery and additional applications at 48 h and 7 days postoperatively. Pain intensity, swelling, trismus, and quality of life were assessed at baseline, 48 h, and 7 days after surgery. RESULTS: The photobiomodulation significantly reduced pain at 48 h (p < 0.001) compared to sham, although no difference was observed on day 7. Swelling resolution was superior in the photobiomodulation group, with facial measurements returning to baseline by day 7, unlike in the sham group. No significant difference was found for trismus. Quality-of-life scores favored photobiomodulation, particularly regarding social activities, swallowing, and sleep quality. CONCLUSIONS: Preemptive photobiomodulation with infrared LED effectively reduces early postoperative pain and accelerates edema resolution in lower third molar surgery. This simple, non-invasive, and low-cost intervention improves recovery and enhances patient comfort. Further studies are warranted to confirm these findings and optimize treatment protocols. CLINICAL SIGNIFICANCE: Preemptive photobiomodulation using infrared LED may serve as an effective adjunctive therapy to improve early postoperative recovery after mandibular third molar surgery. Its ability to reduce pain and accelerate edema resolution can enhance patient comfort and quality of life while offering a non-invasive and cost-effective approach easily integrated into routine clinical practice.