1. a Graduate PhD student, Department of Prosthodontics, West China College of Stomatology, Sichuan University, Sichuan, China
2. b Professor and Department Chair, Department of Prosthodontics, West China College of Stomatology, Sichuan University, Sichuan, China
3. c Professor, Department of Prosthodontics, West China College of Stomatology, Sichuan University, Sichuan, China