Corresponding Author

Department of Geriatric Dentistry, Peking University Hospital of Stomatology, Beijing, China

National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, China

Correspondence

Mingming Xu, Department of Geriatric Dentistry, Peking University Hospital of Stomatology, No.22, Zhongguancun south street, Beijing, China.

Email: anniemmx@126.com

Xuejun Ge, Shanxi Medical University School and Hospital of Stomatology, No.63, Xinjian South Road, Taiyuan, Shanxi.

Email: gxj19722003@163.com