1. Division of Periodontology and Implant Dentistry; Faculty of Dentistry; University of Hong Kong; Hong Kong China
2. European Research Group on Periodontology; Genova Italy
3. Clinic of Fixed and Removable Prosthodontics and Dental Material Science; University of Zurich; Zurich Switzerland
4. Department of Periodontics; The University of Iowa; Iowa City Iowa
5. Department of Surgery and Medical-Surgical Specialties (Dentistry area); Unit of Periodontology; University of Santiago de Compostela; Santiago Spain
6. Department of Dentistry; University of Ghent; Ghent Belgium
7. Division of Periodontology; University of Würzburg; Würzburg Germany
8. ETEP (Etiology and Therapy of Periodontal Diseases) Research Group; Department of Dental Clinic Specialties; Faculty of Dentistry; University Complutense; Madrid Spain
9. Department of Periodontology; Hebrew University; Jerusalem Israel
10. Sub-Unit of Periodontology, Halitosis and Periodontal Medicine; Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine; University of Pisa; Pisa Italy
11. Department of Periodontology; Kapodistrian University; Athens Greece
12. Department of Periodontology; Universitat Internacional de Catalunya; Barcelona Spain
13. Department of Periodontology; School of Dental Medicine; University of Bern; Bern Switzerland
14. Private Practice of Periodontology and Implantology; Geel Belgium