1. Department of Periodontics and Oral Medicine University of Michigan School of Dentistry Ann Arbor Michigan USA
2. Department of Periodontics University of Pittsburgh School of Dentistry Pittsburgh Pennsylvania USA
3. Shanghai PerioImplant Innovation Center, Department of Oral and Maxillofacial Implantology, National Clinical Research Center of Stomatology, Ninth People's Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
4. European Research Group on Periodontology Genoa Italy