1. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases West China Hospital of Stomatology, Sichuan University Chengdu P.R. China
2. Hospital of Stomatology Guanghua School of Stomatology, Sun Yat‐sen University and Guangdong Key Laboratory of Stomatology Guangzhou P.R. China
3. State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Dental Technology West China Hospital of Stomatology, Sichuan University Chengdu P.R. China