Department of Odontology
Division of Periodontology

 The effects of therapeutic lasers in periodontal inflammation.


The aim of this study was to examine the effects of irradiation with therapeutic (“low level”) laser or placebo on inflamed gingival tissue, in a double blind study with control on the same patient. The test area comprised the teeth 13, 14, 15, 16, 17 and 23, 24, 25, 26, 27, respectively, where one side was treated with active laser and the other side with a placebo laser. The areas treated were (1) the buccal papillae with 635 nm during 90 seconds (0, 9 Joule) and (2) 6 mm further apically with 830 nm during 25 seconds (1, 75 Joules). Each wavelength was used separately. 17 patients were treated, 10 women and 7 men.

The laser therapy started one week after scaling and root planning on both sides and continued once a week for 6 weeks. The patients were examined before and after treatments. The clinical parameters were: gingival index (GI), plaque index (PI) and pocket depth. The study was supported by a quantitative analysis of inflammation variables in the gingival fluid (GCF). The GCF volume was measured with a Periotron™ 8000. The elastase activity and the amount of interleukin-1β (IL-1β) and metalloproteinase-8 (MMP-8) were measured in the GCF.



There was a significant pocket reduction on the laser side as compared to the placebo side: 0.92 vs. 0.16 mm (p=0.001). The remaining clinical variables were also significantly reduced on the laser side: GI 0.54 vs. 1.4 (p=0.001), PI 0.26 vs. 0.68 (p=0.01). The GCF volume decreased more on the laser side, – 0.14µl, than on the placebo side,– 0.04µl (p=0.01). The quantity of MMP-8 increased on the placebo side and was somewhat reduced on laser side (p=0.06). The elastase activity and the quantity of IL-1β were, however, the same in both areas.


The additional treatment with low level laser had a positive effect on the periodontal inflammation.