1. Department of Diagnostic Imaging, Dental Allergology and Physiotherapy, Faculty of Dental Medicine Medical University of Plovdiv Plovdiv Bulgaria
2. Department of Conservative Dentistry, Faculty of Dental Medicine Medical University of Sofia Sofia Bulgaria
3. Department of Prosthetic Dental Medicine, Faculty of Dental Medicine Medical University of Plovdiv Plovdiv Bulgaria
4. Department of Diagnostic Imaging, Medical Faculty Medical University of Plovdiv Plovdiv Bulgaria