1. Department of Prosthodontics, School of Dentistry National and Kapodistrian University of Athens Athens Greece
2. Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry Aristotle University of Thessaloniki Thessaloniki Greece
3. Department of Orthodontics, School of Dentistry National and Kapodistrian University of Athens Athens Greece
4. Department of Prosthodontics, School of Dentistry Aristotle University of Thessaloniki Thessaloniki Greece