Direct evidence of collagenolysis in chronic periodontitis

Background:  There is no previous evidence that collagenases in chronic periodontitis excessively cleave collagen fibrils. Objectives:  In this study the eventual presence of neoepitopes produced in such a cleavage were looked for. Methods:  A polyclonal antibody, which recognizes collagenase-cleaved collagen type I 3/4 carboxy-terminal neoepitope (COL1-3/4C), was used in avidin–biotin–peroxidase complex staining. Results:  In addition, moderate staining was seen in connective tissue bordering to the sulcular and junctional epithelium, surrounding some of the fibroblasts and in some areas infiltrated by inflammatory mononuclear cells. COL1-3/4C staining in chronic periodontitis was more extensive (6.3 ± 1.2%, n = 10) and intense than that observed in controls (1.6 ± 0.7%, n = 10, Unpaired Student's t-test, p < 0.01). Conclusions:  It is concluded that collagenases produced by host cells contribute to periodontal tissue destruction and attachment loss.