1. Department of Periodontology and Oral Implantology, Faculty of Medicine and Health Sciences, Dental School; University of Ghent Belgium, Department of Prosthodontics, University of Malmo; Malmo; Sweden
2. Department of Periodontology and Oral Implantology, Faculty of Medicine and Health Sciences, Dental School; University of Ghent; Ghent; Belgium
3. Department of Prosthodontics; University of North Carolina; Chapel Hill; NC; USA
4. Department of Oral and Maxillofacial Surgery; University of North Carolina; Chapel Hill; NC; USA
5. Department of Prosthodontics, Dentistry School; Universitat Internacional de Catalunya; Catalunya; Spain
6. Research Department, Dentistry School; Universitat Internacional de Catalunya; Catalunya; Spain
7. Department of Oral and Maxillofacial Surgery; University of Schleswig-Holstein; Campus Kiel; Germany
8. Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry; Christian-Albrechts University at Kiel; Kiel; Germany