Expression levels of MMP-2 and MMP-9 in dentin of healthy adults under different bonding conditions and their significances / 吉林大学学报(医学版)

ABSTRACT

Objective; To investigate the expression levels of matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) in dentin of healthy adults under different adhesion conditions, and to provide the basis for improving the binding effect of matrix metalloproteinases (MMPs) inhibitors in clinic. Methods; A total of 20 adult freshlyextracted molars were collected and ground into dentin powder under liquid nitrogen cooling. The oral condition was simulated. The dentin was treated with self-etching bonding (Single Bond Universal) and totaletching bonding (35% phosphate gel +Adpter Single Bond 2). The dentin without any treatment was regarded as negative control group, the dentin treated with 10% phosphoric acid (self-etching bonding) or 10% phosphoric acid+ 35% phosphate gel (total-etching bonding) was regarded as positive control group, the dentin treated with Single Bond Universal (self-etching bonding) or 35% phosphate gel+Adper Single Bond 2 (total-etching bonding) was regarded as blank control group; the dentin pretreated with the MMPs inhibitors chlorhexidine (CHX) and minocycline (MI) during the bonding process respectively was regarded as CHX group and MI group, and the dentin treated with 10 % sodium hypochlorite was regarded as aging group; on the basis of aging group, the dentin treated with CHX and MI was regarded as CHX aging group and MI aging group. Gelatin zymography was used to perform the polyacrylamide gel electrophoresis; after incubating, staining and decoloring, the bands were analyzed by gel image analysis system, and the expression levels of MMP-2 and MMP-9 in dentin were calculated. Results: Under the condition of self-etching bonding, compared with blank control group, the expression levels of MMP-2 and MMP-9 in dentin in CHX group were decreased (P<0. 05), and the expression levels of MMP-2 and MMP-9 in the dentin powder in MI group were decreased (P<0. 05); compared with aging blank control group, the expression levels of MMP-2 and MMP-9 in dentin in CHX aging group were decreased (P<0. 05), and the expression levels of MMP-2 and MMP-9 in dentin in MI aging group were decreased (P<0. 05). Under the condition of total-etching bonding, compared with blank control group, the expression levels of MMP-2 in dentin in CHX group and MI group were decreased (P<0. 05); compared with aging blank control group, the expression levels of MMP-2 in dentin in CHX aging group and MI aging group were decreased (P<0. 05). Conclusion; In the process of dentin bonding, CHX and MI could slow down the enzymatic reaction and improve the bonding strength by decreasing the expression levels of MMP-2 and MMP-9.