The gingival crevicular fluids were collected every week after the start of force application,and MMP-9 was assayed by using the biochemistry techniques of SDS-PAGE,Western Blot and Gel Doc quantitative analysis system.

• 每周提取实验牙的龈沟液,并应用SDS-PAGE,Western Blot和Gel Doc凝胶成像系统定量检测龈沟液中MMP-9含量的改变。