1. Department of Stomatology, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China.
2. Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan.
3. Division of Oral and Maxillofacial Implantology, Tsurumi University School of Dental Medicine, Yokohama, Japan.
4. Center for Dental Implantology, School of Stomatology, Capital Medical University, Beijing, People's Republic of China.
5. Beijing Key Laboratory for Tooth Regeneration and Function Reconstruction of Oral Tissues, Beijing, People's Republic of China.