1. Faculty of Dentistry; University of Hong Kong; Hong Kong China
2. European Research Group on Periodontology; Genova Italy
3. Free University of Brussels; Brussels Belgium
4. Division of Oral Microbiology and Immunology; Department of Conservative Dentistry, Periodontology and Preventive Dentistry; RWTH University Hospital Aachen; Aachen Germany
5. Department of Periodontology; Johann Wolfgang Goethe-University; Frankfurt Germany
6. Department of Restorative Dentistry; University of Newcastle; Newcastle UK
7. Department of Oral Function and Prosthetic Dentistry; Radboud University Medical Center; Nijmegen The Netherlands
8. Section of Periodontology; Department of Dentistry and Oral Health; Aarhus University; Aarhus Denmark
9. Department of Periodontology; National and Kapodistrian University of Athens; Athens Greece
10. Division of Gerodontology and Removable Prosthodontics; University Clinics of Dental Medicine; University of Geneva; Geneva Switzerland
11. International Centre for Evidence-Based Oral Health; Unit of Periodontology; UCL Eastman Dental Institute; London UK
12. Department of Dentistry and Oral Health; Aarhus University; Aarhus Denmark
13. Division of Dentistry; University of Manchester; Manchester UK
14. Department of Periodontology; Kristianstad University; Kristianstad Sweden
15. Department of Operative Dentistry; Charitè - Universitätsmedizin Berlin; Berlin Germany
16. Research Center for the Study of Periodontal and Peri-implant Diseases; University of Ferrara; Ferrara Italy
17. Community Dentistry and Oral Public Health; Ghent University; Ghent Belgium
18. Department of Oral and Dental Sciences; University of Bristol; Bristol UK
19. Department of Cariology and Gerodontology; Faculty of Dentistry; University of Oslo; Oslo Norway