1. Department of Endodontics, School of Stomatology, Hospital of Stomatology, Tianjin Medical University , Tianjin 300070, China
2. Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College , Tianjin 300192, China
3. Department of Oral Implantology, Tianjin Stomatological Hospital , Tianjin 300041, China