1. State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, P. R. China
2. Sichuan Provincial Engineering Research Center of Oral Biomaterials, Chengdu, Sichuan 610041, China
3. Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, P. R. China
4. Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, P. R. China