1. Department of Medical Technology, Peking University Health Science Center, Beijing, 100081, PR China
2. Department of Dental Materials & Dental Medical Devices Testing Center, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
3. Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
4. Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
5. Fourth Division, Peking University and Hospital of Stomatology, Beijing, 100081, PR China