1. Herbert Betke, Dr med dent, assistant professor, Department of Operative Dentistry, Preventive Dentistry and Periodontology, Georg-August-University Goettingen, Goettingen, Germany
2. Elke Kahler, Dr, research assistant, Department of Medical statistics, Georg-August-University Goettingen, Goettingen, Germany
3. Angelika Reitz, laboratory assistant, Department of Geochemistry, Georg-August-University Goettingen, Goettingen, Germany
4. Gerald Hartmann, Dr, assistant professor, Department of Geochemistry, Georg-August-University Goettingen, Goettingen, Germany
5. Áine Lennon, Dr med dent, research assistant, Department of Operative Dentistry, Preventive Dentistry and Periodontology, Georg-August-University Goettingen, Goettingen, Germany
6. Thomas Attin, Dr med dent, professor and head of Department of Operative Dentistry, Preventive Dentistry and Periodontology, Georg-August-University Goettingen, Goettingen, Germany