Analgesic effects of preinjection low-level laser/light therapy (LLLT) before third molar surgery: a double-blind randomized controlled trial

Oral Surg Oral Med Oral Pathol Oral Radiol. 2017 Sep;124(3):240-247. doi: 10.1016/j.oooo.2017.04.017. Epub 2017 May 4.


Objective: The aim of this study was to evaluate the analgesic effects of low-level laser therapy (LLLT) on preinjection sites in patients scheduled for third molar removal.

Study design: This double-blind randomized controlled trial included 163 healthy patients undergoing third molar extractions. The study participants were randomly divided into an LLLT and a placebo group. Objective and subjective data sets were obtained from physiologic feedback (heart rate and sweat response) and a questionnaire, respectively. In the LLLT group, each targeted injection site was irradiated twice with 198 mW continuous wave for 30 seconds with a 0.088 cm2 focal spot at an applied energy of 5.94 J and fluence of 67.50 J/cm2. Measurements were recorded from 4 time-points during data acquisition.

Results: There was no significant difference between the LLLT and placebo groups in pain experience scores associated with the injected sites for maxillary or mandibular third molar extractions. Mean heart rates before and during injection were lower in the LLLT group than in the placebo group for both maxillary and mandibular regions. No statistically significant differences were observed for any remaining parameters.

Conclusions: The present data indicated that preinjection LLLT did not effectively decrease the pain felt during local anesthetic injections before third molar surgery.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anesthesia, Dental / methods*
  • Dental Anxiety / diagnosis
  • Double-Blind Method
  • Feedback, Physiological
  • Female
  • Humans
  • Low-Level Light Therapy / methods*
  • Male
  • Middle Aged
  • Molar, Third / surgery*
  • Pain Management / methods*
  • Pain Measurement
  • Tooth Extraction
  • Treatment Outcome