1. Department of Restorative Dentistry and Endodontics, Clinic of Dental Medicine, Faculty of Medicine, University of Niš, Niš, Serbia
2. Department of Medical Statistics and Informatics, Public Health Institute, Faculty of Medicine, University of Niš, Niš, Serbia
3. Department of Prosthodontics, Clinic of Dental Medicine, Faculty of Medicine, University of Niš, Niš, Serbia