1. Department of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology and National Clinical Research Center for Oral Disease, Beijing, PR China.
2. Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China.
3. The Fifth Clinical Division, Peking University School and Hospital of Stomatology, Beijing, PR China.