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