1. Department of Periodontology; Operative & Preventive Dentistry; University of Bonn; Bonn Germany
2. Department of Stomatology; University of Santiago de Compostela; Santiago de Compostela Spain
3. Department for Conservative Dentistry and Periodontology; University Medical Center Regensburg; Regensburg Germany
4. Faculty of Medicine and Dentistry; Catholic University of Louvain; Brussels Belgium
5. The School of Dentistry; University of Birmingham; Birmingham UK
6. Clinic for Conservative Dentistry and Periodontology; Christian-Albrechts-University Kiel; Kiel Germany
7. University of Leeds; University of Kent; Canterbury UK
8. Periodontology; University Complutense; Madrid Spain
9. Radboud University Medical Center; Nijmegen The Netherlands
10. Department of Surgical, Medical, Molecular and Critical Area Pathology; University of Pisa; Pisa Italy
11. Department of Health Services Research & School of Dentistry; University of Liverpool; Liverpool UK
12. Unit of Periodontology; University Medicine; Ernst-Moritz-Arndt-University Greifswald; Greifswald Germany
13. Department of Preventive and Social Dentistry; Federal University of Rio Grande do Sul; Porto Alegre Brazil
14. Department of Preventive & Pediatric Dentistry; University of Greifswald; Greifswald Germany
15. Department of Periodontology; School of Dental Medicine; University of Bern; Bern Switzerland
16. Piracicaba Dental School; University of Campinas (UNICAMP); Piraciaba Brazil
17. Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam; University of Amsterdam and VU University; Amsterdam The Netherlands
18. Oral Hygiene School; Hogeschool Inholland; Amsterdam The Netherlands
19. Clinic of Dental and Oral Pathology; Lithuanian University of Health Sciences; Kaunas Lithuania