Periodontitis is characterized by the loss of connective tissue attachment between the root and the supporting alveolar bone. One group of enzymes thought to be important in this degradative process is the matrix metalloproteinase family(MMPs). Matrix metalloproteinases(MMPs) are thought to be the main proteinase of tissue destruction in periodontal diseases and other diseases, such as rheumatoid arthritis, skin diseases and cancer(Birkendal-Hansen 1993). MMP activity is inhibited by tissue inhibitors of metalloproteinase(TIMPs), which are produced by host cells(Woessner 1991). The role of tissue inhibitors of metalloproteinases may be to tightly control metalloproteinases activity both at the level of gene expression, activation and subsequent substrate degradation. The tissue degradation is further thought to be induced by an imbalance between MMPs and TIMPs(Nomura et al. 1993). Metalloproteinases are mainly synthesized by connective tissue cells and also be synthesized by hemopoietic cells, including monocytes, macrophages, keratinocytes, endothelial cells and many types of tumor cells. The family of MMPs has major subgroups, the interstitial collagenases(MMP1,-8,and-13), the gelatinases(MMP-2 and -9), the stromelysins(MMP-3, -10, -11) and the membrane bound group(MMP-14,-15, -16,-17). Other groups are matrilysin(MMP-7) and metalloelastase(MMP12). The purpose of this study is to determine whether specific MMPs(-1,-2,-3,-8,-9,-13) and TIMPs(-1,-2) are present more in GCF of periodontitis patients than in that of healthy patients by using ELISA assays, and whether the results of these assays have relationship with periodontal probing depth and GI scores, which are the most useful methods in evaluating periodontal status and identify the degrees of periodontal disease in periodontititis patients.
