1. The State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, Sichuan 610041, P.R. China
2. National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064, P.R. China
3. Department of Oral and Maxillofacial Surgery, West China College of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China