Effect of low-level laser therapy on tooth sensitivity induced by in-office bleaching

Lasers Med Sci. 2016 May;31(4):713-9. doi: 10.1007/s10103-016-1913-z. Epub 2016 Mar 10.


This study aimed to investigate the effect of low-level laser therapy (LLLT) on tooth sensitivity induced by in-office bleaching. Sixty-six patients enrolled in this randomized clinical trial. Following the in-office procedure with 40% hydrogen peroxide, the participants were randomly divided into three groups. The patients in group 1 received irradiation from a low-level red laser (LLRL; 660 nm, 200 mW, 15 s, 12 J/cm(2)), whereas participants in group 2 were subjected to a low-level infrared laser (LLIL; 810 nm) under similar conditions as in group 1. In group 3 (placebo), the laser treatment was the same as that in groups 1 and 2, but without energy output. The degree of tooth sensitivity was recorded at 1, 24, and 48 h after bleaching using a visual analog scale (VAS). The change in tooth shade was measured 30 days after tooth whitening. The intensity of tooth sensitivity was not significantly different between groups at 1 h after bleaching (p > 0.05). At 24 h after therapy, pain level was significantly lower in the LLIL group compared to the LLRL and placebo groups (p < 0.05). At 48 h after bleaching, VAS scores in the LLIL and LLRL groups were comparable to each other (p > 0.05) and both were significantly lower than that of the placebo group (p < 0.05). There was no significant difference in the efficacy of tooth whitening among groups (p > 0.05). LLLT with an infrared diode laser could be recommended as a suitable strategy to reduce the intensity of tooth sensitivity after in-office bleaching.

Keywords: Bleaching; Hydrogen peroxide; In-office bleaching; Low-level laser; Low-power laser; Pain; Therapy; Tooth sensitivity.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Dentin Sensitivity / etiology
  • Dentin Sensitivity / radiotherapy*
  • Double-Blind Method
  • Female
  • Humans
  • Hydrogen Peroxide / adverse effects
  • Lasers, Semiconductor / therapeutic use*
  • Low-Level Light Therapy*
  • Male
  • Pain Measurement
  • Tooth / drug effects
  • Tooth / physiopathology
  • Tooth / radiation effects
  • Tooth Bleaching / adverse effects*
  • Tooth Bleaching Agents / adverse effects
  • Treatment Outcome
  • Young Adult


  • Tooth Bleaching Agents
  • Hydrogen Peroxide

Associated data

  • IRCT/201408131509N2