1. Department of Periodontology and Oral Implantology; Faculty of Medicine and Health Sciences; Dental School; University of Ghent; Ghent Belgium
2. Department of Prosthetic Dentistry; Malmö University; Malmö Sweden
3. Clinic for Prosthodontics; Centre of Dental Specialist Care; Malmö Sweden
4. Faculty of Medicine and Pharmacy; Dental Medicine; Free University of Brussels (VUB); Brussels Belgium