1. Department of Preventive Dentistry, Periodontology & Implant Biology, School of Dentistry, Faculty of Health Sciences Aristotle University of Thessaloniki (AUTh) Thessaloniki Greece
2. Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry Hannover Medical School (MHH) Hannover Germany
3. Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences Aristotle University of Thessaloniki (AUTh) Thessaloniki Greece