Effect of Photobiomodulation Therapy on Reducing Acute Pain and Inflammation Following Surgical Removal of Impacted Mandibular Third Molars: A Randomized, Split-Mouth Clinical Trial

Photobiomodul Photomed Laser Surg. 2022 Apr;40(4):245-251. doi: 10.1089/photob.2021.0110. Epub 2022 Mar 29.


Objective: This study aimed to compare the effects of photobiomodulation therapy (PBMT) on analgesic and inflammatory reduction with that of ibuprofen following surgical removal of impacted mandibular third molars (IMTMs). Methods: A randomized, split-mouth clinical trial was performed on patients undergoing bilateral IMTM removal. PBMT [gallium aluminum arsenide (GaAlAs) laser] with specific parameters (wavelength of 810 nm, power of 0.5% ± 20% W, and energy density of 4 J/cm2) was applied randomly on one side of the mouth immediately after surgery and 1 and 2 days after surgery. The pain level was self-rated with a Likert scale at 2, 4, 6, 24, and 48 h postoperatively. Swelling and trismus were measured on the first and second day after surgery. Saliva was collected for measuring pre- and postoperative salivary immunoglobulin A (sIgA) concentrations with the sandwich ELISA test. Results: The study sample included 25 patients (average age of 22.88 years) with 50 bilateral symmetrical IMTMs. Pain level was highest at 2 h after surgery in both groups and gradually decreased over time (p < 0.01). Swelling and trismus at 48 h were higher than at 24 h (p < 0.01). Within the first 48 h postoperatively, pain level, swelling, and trismus were significantly lower in the PBMT group (p < 0.05). Postoperative sIgA was also significantly lower in the PBMT group (p < 0.05). Conclusions: In short-term and specific conditions of this study, it was found that PBMT helped promote postoperative pain relief and anti-inflammation after surgical removal of IMTMs. The results suggested that there may be a link between a decrease in salivary sIgA levels and decrease in inflammatory processes after PBMT. Trial Registration No. NCT04280809 at ClinicalTrials.gov.

Keywords: impacted mandibular third molars; low-level laser therapy; pain relief; photobiomodulation therapy; swelling; trismus.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Acute Pain*
  • Adult
  • Edema / etiology
  • Edema / prevention & control
  • Humans
  • Immunoglobulin A, Secretory
  • Inflammation
  • Low-Level Light Therapy* / methods
  • Molar, Third / surgery
  • Mouth
  • Pain, Postoperative / prevention & control
  • Tooth Extraction
  • Trismus / etiology
  • Trismus / prevention & control
  • Young Adult


  • Immunoglobulin A, Secretory

Associated data

  • ClinicalTrials.gov/NCT04280809