The aim of this study was to investigate the effects of the mechanical stress on the proliferation and function of os2 teoblast-like cells (UMR106) of rats , and further to explore the mechanism of remodeling of periodontium from an angle of me2 chanics. Methods :The flow cytometry and MTTmethod was used to examine the number of osteoblasts-like cells and their prolifer2 ation and metabolic enzymic activity 6 h , 12 h , 18 h , 24 h , 30 h , and 36 h after the top- bottom axial stress (225 ×g) was exert2 ed on the UMR106 in vitro. Results :The difference of cell phase fraction and function between the experimental group and the con2 trol group were of great significance ( P
