1. Assistant, Division of Dental Materials; Faculty of Dentistry; Wroclaw Medical University; Wroclaw Poland
2. Professor, Department of Prosthetic Dentistry; Faculty of Medicine; Dresden University of Technology; Dresden Germany
3. Lecturer, Department of Prosthetic Dentistry; Faculty of Medicine; Dresden University of Technology; Dresden Germany
4. Professor and Head, Department of Prosthetic Dentistry; Faculty of Dentistry; Wroclaw Medical University; Wroclaw Poland