SHORT-TERM LOW-LEVEL LASER THERAPY ATTENUATES INFLAMMATION AND PRODUCTION OF INTERLEUKIN-1, BUT ELEVATES THE LEVEL OF MATRIX METALLOPROTEINASE 9 IN CHRONIC PERIODONTITIS

Background / Purpose: Low- level laser therapy (LLLT) has been used as an adjunct to the treatment of chronic periodontitis (CP), but its efficacy has not been well-documented. Therefore, the aim of this study was to investigate the effect of LLLT on clinical parameters in CP patients and their relationship with concentrations of biohumoral markers of inflammation in gingival crevicular fluid (GCF). . Materials and methods: Thirty-six patients were randomly assigned to control and experimental groups after scaling. The experimental group was treated with a diode laser (wavelenght: 635 nm; power density: 100 mW/cm2), by applying the laser beam to diseased teeth for 9 days, whereas the control group did not receive LLLT. Clinical examination was performed at baseline and 10 days after the treatment. GCF samples were collected from the same periodontal site before and after therapy. The levels of interleukin 1 (IL-1) and matrix metalloproteinase 9 (MMP-9) in GCF were measured by ELISA. Results: LLLT decreased clinical parameters of CP. The levels of IL-1α and IL-1β in GCF were decreased (p< 0.05), but the level of MMP-9 was increased (p<0.01). After LLLT, the level of IL-1α correlated positively with MMP-9 (p< 0.05) and the MMP-9 levels correlated negatively with plaque index (p< 0.05) and papillary bleeding index (p< 0.01). Conclusion: LLLT attenuated periodontal inflammation in CP patients, as judged by clinical parameters and decreased levels of IL-1 in GCF. It remains to be studied whether elevated levels of MMP-9 in GCF might be beneficial for reparation processes. Clinical article (J Int Dent Med Res 2014; 7: (1), pp. 7-13)