1. Department of Periodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.
2. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.
3. National Engineering Laboratory for Oral Regenerative Medicine, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.
4. Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.