1. Department of Dental Materials and Biomaterials Research RWTH Aachen University Hospital Pauwelsstrasse 30 Aachen 52074 Germany
2. Department of Prosthodontics and Biomaterials RWTH Aachen University Hospital Pauwelsstrasse 30 Aachen 52074 Germany
3. Flow Cytometry Facility Faculty of Medicine of RWTH Aachen University Hospital Pauwelsstrasse 30 Aachen 52074 Germany
4. Institute of Biochemistry and Molecular Biology Confocal Microscopy Facility RWTH Aachen University Hospital Pauwelsstrasse 30 Aachen 52074 Germany