An Investigation of Matrix Metalloproteinases in Gingival Crevicular Fluid in the Guided Tissue Regeneration Procedure

Matrix metalloproteinases (MMPs) have been implicated in the aetiopathogenesis of periodontitis. MMPs are degradative host proteinases that are not only involved in the destruction process but also in embryologic development, tissue remodeling and wound healing processes. Accumulating evidence has gathered over the years for their involvement in periodontal destruction. Higher level of MMPs has been found in periodontitis sites compared to healthy sites or individuals. The 'active state' of the MMP enzyme has been associated with active periodontal lesions and reductions of MMP levels have been reported following periodontal treatment. Repair and wound healing are most likely to be influenced by the matrix-modifying enzymes, the MMPs. MMP levels have been investigated during wound healing and stromelysin (SL) were found to be overexpressed and overactivated during the wound repair process. SL-1 and -2 have also been found in a variety of chronic wound lesions and also in acute skin wounds, suggesting their roles in tissue repair. MMP-9 levels measured 48 hours after injury can predict the amount of collagen deposited later as higher levels have been linked to retarded healing. Resident connective tissue cells produce MMP-3 and MMP-8 are produced by polymorphnuclear leukocytes (PMN) in addition to fibroblasts of gingivae, mucosae and periodontal ligament. Both PMN and fibroblasts are increased during the wound healing process. PMN predominates immediately after the injury and up to three days after. while an increased number of fibroblasts are found in the granulation tissue after the third day onwards. GTR is now an acceptable technique for the treatment of infrabony defects. Compromised clinical results have been associated with microbial contamination during the membrane insertion. Microbial contamination has also been demonstrated in association with a non-resorbable barrier membrane owing to the lack of tissue integration leading to pocket formation. With resorbable membranes, this factor has been eliminated and the only concern is membrane contamination during insertion. Preliminary microbiological results have demonstrated that GuidorRTM barrier membranes do not seem to develop facultative anaerobic bacteria and black pigmented gram-negative anaerobic rods in high numbers during the first 6 weeks post-operatively. High dose amoxycillin, a broad-spectrum penicillin active against aerobe and facultative anaerobic microflora given 1 hour prior to the guided tissue regeneration (GTR) procedure may reduce the possible contamination of the material and the wound during membrane insertion. The purpose of the study was to investigate the clinical outcome, the microbiological colonization and the levels of matrix metalloproteinases during the wound healing following insertion of a resorbable membrane (GUIDOR) either alone or combined with one presurgical systemic application of amoxycillin. It was also investigated whether the fluctuation of GCF levels of MMP-3 and -8 during the wound healing could be linked to the clinical outcome and microbiological colonization. Gingival crevicular fluid (GCF) samples were collected by means of sterile paper strips and the volume was assessed using the Periotron 6000. Fibroblast derived MMP-3 levels in GCF were assayed using modification of the sandwich ELIS As described by Cooksley et al. (1990). Antibodies detected both the active and the latent MMP-3. MMP-8 levels were determined by a time-resolved fluorescence immunoassay (FIA) as described by Hanemaaijer et al., (1997) for the detection of active MMP-8. The results were expressed as absolute amounts, that is, ng/30s of sample collection. GCF samples were collected from test, surgical control and healthy control sites from each patient. The test sites are the sites treated with membranes and the surgical control sites were the adjacent teeth involved in the surgical flap without the membrane insertion. The MMP-3 levels were only altered at week one for the test sites, while for the surgical control and healthy control sites the levels remained undetectable at all visit. Inspection of individual data revealed that 45% of the surgical sites had detectable increase in MMP-3 at week one. The active MMP-8 levels for the test sites were significantly higher compared to the healthy control sites. For the test there was a significant increase in the MMP-8 levels at week one. There were also increased levels for the surgical sites, but the differences were not significant from the baseline values. Based on evidence presented in the literature about cellular aspects during healing, it can be presumed that most of the MMP-8 levels present after week 1 were derived mostly from fibroblasts