胶原纤维和基质金属蛋白酶9 在大鼠正畸牙根吸收中的表达及意义.

BACKGROUND: Root resorption is the most common complication in orthodontic treatment, and is also a hot topic in current orthodontic research. Currently, the remodeling process of collagen fibers in the inferior periodontal tissue and its relationship with matrix metalloproteinase-9 remain unclear at different time points during root resorption. OBJECTIVE: To investigate the remodeling of collagen fibers and the expression of matrix metalloproteinase-9 in the inferior periodontal tissue at different time points on the pressure side during orthodontic root resorption. METHODS: Thirty eight-week-old male Wistar rats were selected, and the orthodontic tooth movement model was established by pulling the left maxillary first molars towards the near middle in the experimental group, and the right side was not treated as the control group. The changes of collagen fibers and expression of matrix metalloproteinase-9 in alveolar bone, root surface and periodontal tissue at 1, 3, 5, 7, 14, and 21 days were observed and analyzed by histomorphology after force application. RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining and Masson's trichrome staining results confirmed that compared with the control group, the alveolar bone and tooth root surface of the experimental group had different degrees of resorption. The periodontal tissue collagen fibers underwent structural remodeling. The remodeling was most significant at 7 and 21 days. The expression of collagen fibers per unit area decreased first and then increased with the extension of the force. (2) Immunohistochemical staining confirmed that compared with the control group, the expression of matrix metalloproteinase-9 in the experimental group increased. The expression level showed a trend of first increasing and then decreasing with the extension of the application time. Pearson correlation analysis confirmed that the matrix metalloproteinase-9 expression was negatively correlated with the expression of collagen fibers in periodontal tissues (r=-0.933, P < 0.01). (3) The above results indicate that during orthodontic tooth root resorption in rats, the collagen in periodontal tissues is prolonged with time of stress. The expression level of matrix metalloproteinase-9 is related to the dynamic changes of collagen fibers and the changing trend of tooth root resorption. [ABSTRACT FROM AUTHOR]