1. Department of Periodontology and Operative Dentistry, University Medical Center, Johannes Gutenberg University, 55131 Mainz, Germany
2. University Medical Center, University of Mainz, Rudolf Frey Lernklinik, 55131 Mainz, Germany
3. Center for Quality Assurance and Development (ZQ), Johannes Gutenberg University Mainz, 55124 Mainz, Germany
4. Department of Psychosomatic Medicine and Psychotherapy, Medical Psychology and Medical Sociology, University Medical Center, Johannes Gutenberg-University, 55099 Mainz, Germany