1. Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
2. Rutgers School of Dental Medicine, Rutgers University, Newark, NJ 07103, USA
3. Department of Stomatology, The Second Hospital of Nanjing, Nanjing, Jiangsu 210003, P.R. China
4. AK Medical Holdings Limited, Beijing 100101, P.R China