1. Institute of Mineral Engineering, Chair of Ceramics, RWTH Aachen University, Forckenbeckstrasse 33, 52074 Aachen, Germany
2. Department of Biomaterials and Composites, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
3. Institute of Mineral Engineering, Chair of Glass and Glass-ceramic, RWTH Aachen University, Forckenbeckstrasse 33, 52074 Aachen, Germany
4. Faculty of Chemistry, Silesian University of Technology, Gliwice, Poland and Biotechnology Centre, Silesian University of Technology, 44-100 Gliwice, Poland
5. Department of Restorative Dentistry and Endodontology, Justus-Liebig-University Giessen, Schlangenzahl 14, 35392 Gießen, Germany