Matrix Metalloproteinase Levels in Chronic Periapical Lesions and Inflamed Dental Pulps

The aim of this study was to accomplish quantitative measurement of tissue levels of collagenases (MMP-1, 8 and 13) in chronic inflamed tissues (pulp and periapical lesions), as well as to determine the dependence between collagenase level and the degree of tissue destruction of examined material. Chronic periapical tissues were collected by periapical surgery from 50 teeth with clinically and radiographically verified different chronic periapical lesions (20 granulomas, 20 diffuse periapical lesions, 10 cysts). Chronically inflamed pulps were obtained from 20 patients by endodontic treatment. Control group contained vital dental pulps from 10 impacted third molars. For rapid analysis of MMP-1, 8 and 13 collagenase activities in the examined material Chemicon Collagenase Activity Assay Kit was used. The biggest values of concentration of MMPs were registered in chronic diffuse lesions (5.39 ng/mL). Expression and activity of MMPs in normal tissue of pulp from impacted third molars was from 0.00 to 0.02 ng/ mL. Different concentrations of collagenases (MMP-1, 8 and 13) in chronic periapical lesions from different inflammation types showed different activity of MMPs, which was confirmed with high significant difference (ANOVA F=67.475; df=4; p=0.000). The concentration of collagenases (MMP-1, 8 and 13) in chronically inflamed pulp was from 0.1-1.28 ng/mL, which means that inflammation process was still localized in pulp tissue only, and periapical connective tissue was not affected. We conformed the destructive role of collagenases (MMP-1, 8 and 13) in inflammation processes, which is directly dependent from the concentration of MMPs in pathologically changed tissue. With respect to conventional methods in everyday dental practice, this study recommended determination of MMPs (proteolytic enzymes) as the most sensitive markers in chronically inflamed tissues, which opens new opportunities to contemporary methods of evaluation and monitoring of inflammation activity in chronic periapical lesions.