1. Section for Oral Ecology and Caries Control, Department of Dentistry and Oral Health Aarhus University Aarhus Denmark
2. Clinic of Reconstructive Dentistry, Center of Dental Medicine University of Zurich Zurich Switzerland
3. Division of Oral Microbiology and Immunology, Clinic of Conservative and Preventive Dentistry, Center of Dental Medicine University of Zurich Zurich Switzerland
4. Section for Microbiology, Department of Biology Aarhus University Aarhus Denmark