1. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, P. R. China
2. The Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, China
3. Sichuan Provincial Engineering Research Center of Oral Biomaterials, Chengdu, Sichuan 610041, China