1. State Key Laboratory of Oral Diseases; West China School of Stomatology; Sichuan University; Chengdu China
2. Department of Prosthodontics; West China School of Stomatology; Sichuan University; Chengdu China
3. Oral Implant Center; West China School of Stomatology; Sichuan University; Chengdu China
4. Sidney Kimmel Medical College at Thomas Jefferson University; Philadelphia PA USA