1. Division of Periodontology and Implant Dentistry, Faculty of Dentistry The University of Hong Kong Hong Kong China
2. Shanghai PerioImplant Innovation Center, Department of Oral and Maxillofacial Implantology, National Clinical Research Center of Stomatology Ninth People' Hospital, Shanghai Jiao Tong University School of Medicine Shanghai China
3. European Research Group on Periodontology Genoa Italy