Effect of Nonsurgical Periodontal Therapy with Additional Photodynamic Therapy on the Level of MMP-9 and TIMP-1 in GCF in Chronic Periodontitis Patients- a Preliminary Pilot Study.

Purpose: Matrix metalloproteinases (MMPs) catalyze degradation of extracellular matrix proteins. The activity of MMPs is controlled by tissue inhibitors of metalloproteinases (TIMPs). An imbalance in the MMP-9/TIMP-1 ratio has been linked with chronic periodontitis (CP). Photodynamic therapy (PDT) uses visible light, photosensitizer and oxygen to eradicate pathogens. The aim of the study was to evaluate the presence of MMP-9 and TIMP-1 in gingival crevicular fluid (GCF) in chronic periodontitis patients before and after nonsurgical periodontal therapy with additional PDT. Methods: Nineteen patients, each with CP, were included in the study. After periodontal examination one site with a probing depth (PD) >= 4 mm was selected. The patients received scaling and root planing (SRP) with additional PDT by means of HELBO (R) diode minilaser. Prior to treatment, and after 3 and 6 months, the following parameters were estimated from the same site: PD, gingival recession (GR), clinical attachment level (CAL), plaque index (PI), bleeding on probing (BOP) and sulcus fluid flow rate (SFFR). The levels of MMP-9 and TIMP-1 in GCF were determined. Results: Compared to baseline, the levels of MMP-9 and TIMP-1 did not show statistically significant differences after 3 and 6 months. According to Spearman's rank correlations, MMP-9 was positively correlated with SFFR at all time points. PD, CAL and PI showed a statistically significant decrease compared to baseline (p < 0.001). SFFR decreased but not significantly. Conclusion: Nonsurgical periodontal therapy in conjunction with PDT was clinically effective but it had no effect on the levels of MMP-9 and TIMP-1 in GCF.