1. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
2. National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
3. College of Biomedical Engineering, Sichuan University, Chengdu 610064, China
4. Sichuan Testing Center for Biomaterials and Medical Devices, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China