1. Department of Prosthodontics and Materials Science, University of Leipzig, Liebigstr. 12, 04103 Leipzig, Germany
2. Private Practice, Praxis Dietrich Mehlhorn, Tannenbergsthaler Str. 7, 08269 Muldenhammer, Germany
3. Department of Cariology, Endodontology and Periodontology, University of Leipzig, Liebigstr. 12, 04103 Leipzig, Germany