1. Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany
2. Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, UK
3. Department of Prosthetic Dentistry, Faculty of Medicine, Center for Dental Medicine, University of Freiburg, Freiburg, Germany
4. Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
5. Department of Operative Dentistry and Periodontology, Faculty of Medicine, Center for Dental Medicine, University of Freiburg, Freiburg, Germany
6. Department of Orthodontics, University Hospital Regensburg, Regensburg, Germany
7. Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg, Regensburg, Germany