The short-term effects of low-level lasers as adjunct therapy in the treatment of periodontal inflammation

J Clin Periodontol. 2005 Jul;32(7):714-9. doi: 10.1111/j.1600-051X.2005.00749.x.


Objectives: The aim of this split-mouth, double-blind controlled clinical trial was to study the effects of irradiation with low-level lasers as an adjunctive treatment of inflamed gingival tissue.

Materials and methods: Seventeen patients with moderate periodontitis were included. After clinical examination, all teeth were scaled and root planed (SRP). One week after SRP, we took samples of gingival crevicular fluid (GCF) and subgingival plaque. The laser therapy was started 1 week later and continued once a week for 6 weeks. One side of the upper jaw was treated with active laser and the other with a placebo. The test side was treated with two low-level lasers having wavelengths of 635 and 830 nm. The patients then underwent another clinical examination with sampling of GCF and plaque. The GCF samples were analysed for elastase activity, interleukin-1beta (IL-1beta) and metalloproteinase-8 (MMP-8). We examined the subgingival plaque for 12 bacteria using DNA probes.

Results: The clinical variables i.e. probing pocket depth, plaque and gingival indices were reduced more on the laser side than on the placebo one (p<0.01). The decrease in GCF volume was also greater on the laser side, 0, 12 microl, than on the placebo side, 0.05 microl (p=0.01). The total amount of MMP-8 increased on the placebo side but was slightly lower on the laser side (p=0.052). Elastase activity, IL-1beta concentration and the microbiological analyses showed no significant differences between the laser and placebo sides.

Conclusion: Additional treatment with low-level lasers reduced periodontal gingival inflammation.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Chronic Disease
  • Dental Plaque / microbiology
  • Dental Scaling
  • Double-Blind Method
  • Female
  • Gingival Crevicular Fluid / chemistry
  • Gingival Crevicular Fluid / enzymology
  • Humans
  • Interleukin-1 / analysis
  • Leukocyte Elastase / analysis
  • Low-Level Light Therapy*
  • Male
  • Matrix Metalloproteinase 8 / analysis
  • Middle Aged
  • Nucleic Acid Hybridization
  • Periodontitis / radiotherapy*
  • Radiotherapy, Adjuvant
  • Statistics, Nonparametric


  • Interleukin-1
  • Leukocyte Elastase
  • Matrix Metalloproteinase 8