1. *Bora Korkut, PhD, DDS, Department of Restorative Dentistry, Dentistry Faculty, Marmara University, Basibuyuk, Maltepe, Istanbul, Turkey
2. Mutlu Özcan, PhD, DDS, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Center for Dental and Oral Medicine, Dental Materials Unit, University of Zurich, Zurich, Switzerland