Effect of low-level laser therapy combined with 5000 parts per million fluoride dentifrice on postbleaching sensitivity: A clinical, randomized, and double-blind study

J Esthet Restor Dent. 2018 Jul;30(4):352-359. doi: 10.1111/jerd.12386. Epub 2018 Aug 6.


Objective: The aim of this double-blind, randomized, controlled clinical study was to assess the efficacy of low-level laser therapy (LLLT) combined with 5000 ppm fluoride dentifrice on postbleaching sensitivity in teeth exposed to 35% hydrogen peroxide for four weeks.

Materials and methods: Twenty-five volunteers were evaluated using the split-mouth model in which the right and left maxillary/mandibular quadrants were randomized and allocated to one of two groups: GPLACEBO, in which the laser tip was positioned without the emission of light (placebo effect) + 5000 ppm sodium fluoride, or GLASER, which comprised LLLT + 5000 ppm sodium fluoride. For both groups, LLLT and placebo were used before bleaching, whereas fluoride was applied after bleaching. LLLT was applied at two points: on the central cervical and medial regions of the incisors, canines, and premolars in the corresponding hemi-arch. At each point, 60 J/cm2 was applied for 16 seconds with an irradiance of 3.75 W/cm2 using the therapeutic infrared device. To assess tooth sensitivity, a modified visual analogue scale was used after an evaporative stimulus, and a daily pain questionnaire was also applied.

Results: The Wilcoxon and Friedman tests demonstrated a significant difference in the incidence of sensitivity pain between GPLACEBO and GLASER (P ≤ .05), with different evaluation times.

Conclusion: Teeth treated with laser therapy in combination with the topical use of sodium fluoride at each bleaching session demonstrated less sensitivity compared with the application of sodium fluoride only.

Clinical significance: The use of a low-level laser therapy in combination with topical use of sodium fluoride improves symptoms of dentin sensitivity at each bleaching session.

Keywords: dental bleaching; desensitization; low-level laser therapy; sodium fluoride.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Dentifrices*
  • Dentin Sensitivity*
  • Double-Blind Method
  • Fluorides
  • Humans
  • Low-Level Light Therapy*
  • Tooth Bleaching* / adverse effects
  • Treatment Outcome


  • Dentifrices
  • Fluorides