Collagenolytic activity following regenerative treatment of intrabony periodontal defects

The objective of this study was to evaluate the sequential gingival crevicular fluid (GCF) levels of matrix metalloproteinase-8 (MMP-8) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in patients with chronic periodontitis during regenerative treatment of intrabony periodontal defects with the combination of enamel matrix derivative (EMD) and bovine-derived xenograft (BDX). This study included 10 chronic periodontitis patients aged between 28-61 (mean 46.2± 10.4) years. A total of 20 intrabony defects with a probing depth (PD) of 15 mm detected 8 weeks after initial therapy and an intrabony component of 14 mm confirmed during surgery were selected. Defects were surgically treated with EMD/BDX. Clinical measurements including plaque index (PI), sulcus bleeding index (SBI), PD, relative attachment level (RAL) and recession (REC) were recorded at baseline and 96 weeks after treatment. GCF samples were collected at baseline and 2, 4, 12 and 96 weeks following surgery by means of paper strips. After determination of GCF volume, MMP-8 and TIMP-1 levels were measured by using an enzyme-linked immunosorbent assay. Results showed that all clinical parameters including PI (p<0.01), SBI (p<0.01), PD (p<0.001), RAL (p<0.01) and REC (p<0.01) improved significantly after therapy. At week 2 following surgery, MMP-8 levels increased significantly (p<0.05) whereas the increase in TIMP-1 levels were not significant (p>0.05). Four weeks after surgery, MMP-8 levels showed a significant decrease (p<0.05) while this decrease levels in TIMP-1 levels were found insignificant (p>0.05). Decrease in MMP-8 and TIMP-1 levels were also found at weeks 12 (p<0.01 and p<0.05) and 96 (p<0.001 and p<0.05) when compared to baseline. At week 96, GCF volume change was found to be significantly correlated with PI and SBI (p<0.05) whereas significant correlation was found between enzyme concentrations and PD reduction and attachment gain (p<0.05). Within the limits of this preliminary study, GCF volume, MMP-8 and TIMP-1 levels seem to reflect the soft tissue remodelling during the wound healing following regenerative treatment of intrabony defects in chronic periodontitis patients.