Methods Investigate the plaque index (PLI) of 100 cases of orthodontic children in pre-treatment, initial-treatment, post-treatment and maintainer by using plaque disclosing agent.

• 方法通过100例正畸儿童使用菌斑染色剂染色并给予全面的口腔卫生指导,分别对矫治前、矫治初期、矫治末期、保持期进行菌斑指数（PLI）测试及比较。