1. Department of Periodontology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg; Gothenburg Sweden
2. University of California San Francisco; San Francisco CA USA
3. State University of Maringa; Parana Brazil
4. University of Iowa; Iowa City IA USA
5. Universidad Santiago de Compostela; Santiago Spain
6. University of California Los Angeles; Los Angeles CA USA
7. University of Melbourne; Melbourne Australia
8. University of Texas Health Science Center; San Antonio TX USA
9. Universidad Complutense; Madrid Spain
10. Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich; Zurich Switzerland
11. University of Sydney; Sydney Australia
12. Stony Brook University; Stony Brook NY USA
13. Seoul National University; Seoul South Korea
14. Department of Periodontology and Oral Surgery, University of Liège; Liège Belgium
15. School of Dentistry, University of Michigan; Ann Arbor MI USA
16. Leuven University; Flanders Belgium
17. Kristianstad University; Kristianstad Sweden
18. Department of Periodontology, University of Bern; Bern Switzerland
19. Department of Oral Surgery and Implantology, Carolinum, Goethe University; Frankfurt Germany
20. Columbia University; New York NY USA
21. Department of Reconstructive Dentistry, University of Basel; Basel Switzerland