1. Division of Dental Materials, Faculty of Dentistry, Wroclaw Medical University, 50425 Wroclaw, Poland
2. Department of Periodontology, Faculty of Dentistry, Wroclaw Medical University, 50425 Wroclaw, Poland
3. Department of Prosthetic Dentistry, Faculty of Dentistry, Wroclaw Medical University, 50425 Wroclaw, Poland