1. Department of Prosthetic Dentistry, Faculty of Dental Medicine, Medical University–Plovdiv, 4000 Plovdiv, Bulgaria
2. CAD/CAM Center of Dental Medicine, Research Institute, Medical University–Plovdiv, 4000 Plovdiv, Bulgaria
3. Department of Periodontology and Oral Mucosa Diseases, Faculty of Dental Medicine, Medical University–Plovdiv, 4000 Plovdiv, Bulgaria
4. Laser Dental Center, Research Institute, Medical University–Plovdiv, 4000 Plovdiv, Bulgaria
5. Private Dental Practice–Sofia, 1000 Sofia, Bulgaria
6. Department of Interdisciplinary Medicine, University of Bari ‘Aldo Moro’, 70100 Bari, Italy