1. Department of Operative Dentistry and Endodontics, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat‑sen University and Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong 510055, P.R. China
2. Stomatological Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
3. Department of Stomatology, Shenzhen Children's Hospital, Shenzhen, Guangdong 518038, P.R. China