1. Department of Periodontology and Oral Implantology; Faculty of Medicine and Health Sciences; Dental School; Ghent University; Ghent Belgium
2. Oral Health Research Group (ORHE); Faculty of Medicine and Pharmacy; Vrije Universiteit Brussel (VUB); Brussels Belgium
3. Department of Prosthodontics; Faculty of Odontology; Malmö University; Malmö Sweden