1. Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovića 69, 34000 Kragujevac, Serbia
2. Dental Clinic, Military Medical Academy, University of Defence, Crnotravska 17, 11000 Belgrade, Serbia
3. Department of Physiology, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovića 69, 34000 Kragujevac, Serbia