1. Department of Prosthodontics; School and Hospital of Stomatology; Peking University; 22# Zhong Guan Cun South Street Beijing 100081 China
2. First Clinical Division; School and Hospital of Stomatology; Peking University; 37# Xishiku Street Beijing 100034 China
3. National Engineering Laboratory for Digital and Material Technology of Stomatology; Beijing Key Laboratory of Digital Stomatology; 22# Zhong Guan Cun South Street Beijing 100081 China
4. Department of Ocean and Mechanical Engineering; Florida Atlantic University; Boca Raton FL 33431 USA
5. Department of Orthopaedic Surgery; Department of Materials Science and Engineering; Department of Bioengineering; Stanford University; Stanford CA 94305 USA
6. Department of Ocean and Mechanical Engineering; Department of Biomedical Science; Florida Atlantic University; Boca Raton FL 33431 USA