Matrix metalloproteinase-8 (MMP-8) in pulpal and periapical inflammation and periapical root-canal exudate

Aim To study the presence, levels and molecular forms of matrix metalloproteinase (MMP)-8 (collagenase-2) in pulpal and periapical inflammation, and the changes in MMP-8 levels in root-canal exudates during root-canal treatment. Methodology Periapical exudate samples were collected from 11 necrotic teeth with radiographically verified periapical periodontitis during three root-canal treatment visits with interappointment calcium hydroxide (Ca(OH)(2)) medication. MMP-8 levels and molecular forms were analyzed with immunofluorescent assay (IFMA) an Western immunoblot. Inflamed pulp tissue an periapical granuloma tissue (n = 10 for both) were obtained from other patients and use for MMP-8 immunohistochemical (IHC) staining. Result The periapical exudate samples demonstrated marked differences in MMP-8 levels between the teeth in the first visit an significant ecrease in MMP-8 levels during the root-canal treatment ( P = 0.0107). One specimen failed to show a decrease in MMP-8 below 1000 ng mL(-1); a vertical root fracture was later diagnosed and the tooth extracted. IHC staining showed that in a addition to PMN-leucocytes, macrophages and plasma cells produce MMP-8 in pulp and periapical granulomas. Conclusions The findings demonstrate the presence of MMP-8 in the inflamed pulp and periapical tissue, indicating that MMP-8 has a role in pulpal and periapical inflammation, most likely participating in tissue extracellular matrix degradation. They further indicate that MMP analysis from periapical exudate could be use to indicate an monitor inflammatory activity and the success of treatment in teeth with periapical lesions.