1. Department of Geriatric Dentistry
2. Peking University School and Hospital of Stomatology
3. Beijing 100081
4. P. R. China
5. Department of Prosthodonitcs
6. Anesthesia and Operation Centre
7. Chinese PLA General Hospital
8. Beijing 410078
9. School of Materials Science and Engineering
10. South China University of Technology
11. Guangzhou 510641
12. China
13. Department of Dental Materials & Dental Medical Devices Testing Centre
14. Central Laboratory
15. National Engineering Laboratory for Digital and Material Technology of Stomatology