1. ETEP Research Group Faculty of Dentistry Complutense University of Madrid Madrid Spain
2. Division of Periodontics Section of Oral, Diagnostic and Rehabilitation Sciences College of Dental Sciences Columbia University New York New York
3. European Research Group on Periodontology Genova Italy
4. Division of Periodontology and Implant Dentistry Faculty of Dentistry The University of Hong Kong Hong Kong Hong Kong, SAR China
5. Graduate Periodontics School of Dentistry University of Louisville Louisville Kentucky
6. Department of Periodontics and Oral Medicine University of Michigan School of Dentistry Ann Arbor Michigan