1. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
2. Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
3. Department of Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China