Effect of Low-level Laser Therapy on Postoperative Pain in Molars with Symptomatic Apical Periodontitis: A Randomized Placebo-controlled Clinical Trial

J Endod. 2018 Nov;44(11):1610-1615. doi: 10.1016/j.joen.2018.07.002. Epub 2018 Aug 23.


Introduction: In this clinical trial, we evaluated the effect of low-level laser therapy (LLLT) on postoperative pain in mandibular molar teeth with symptomatic apical periodontitis.

Methods: Forty-two patients were included in the study according to the inclusion and exclusion criteria. Root canal treatment was conducted using reciprocating instruments. The patients were randomly distributed into 3 groups using a Web program as follows: control (no laser was applied), placebo (mock laser therapy), and LLLT. Postoperative pain levels on the 1st, 3rd, 5th, 7th, and 30th day and postoperative percussion pain levels on the visual analog scale were recorded. The chi-square, 1-way analysis of variance, and least significant difference post hoc tests were performed to analyze the data (P = .05).

Results: LLLT resulted in lower pain levels than those noted in the control and placebo groups on days 1 and 3 (P < .05). There were no significant differences among the placebo, LLLT, and control groups in terms of postoperative percussion pain levels (P < .05).

Conclusions: LLLT can be beneficial in reducing postoperative pain in endodontics.

Keywords: Endodontics; host biomodulation; lasers; low-level laser therapy; pain.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Female
  • Humans
  • Low-Level Light Therapy / methods*
  • Male
  • Middle Aged
  • Pain, Postoperative / radiotherapy*
  • Periapical Periodontitis / surgery*
  • Root Canal Therapy*
  • Treatment Outcome
  • Young Adult