1. Department for Conservative Dentistry University Hospital of Heidelberg Heidelberg Germany
2. Department for Conservative Dentistry University Hospital of Tübingen Tuebingen Germany
3. Nutrition Support Team University Hospital of Tuebingen Tuebingen Germany
4. Department for Operative Dentistry and Periodontology, Faculty of Medicine University of Freiburg Freiburg im Breisgau Germany
5. Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center University of Freiburg Freiburg im Breisgau Germany
6. Institute of Nutritional Medicine University of Hohenheim Stuttgart Germany