1. Institute of Medical Microbiology and Hygiene, University of Saarland, Homburg/Saar - Germany
2. Department of Experimental Physics, University of Saarland, Saarbrücken - Germany
3. Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University of Saarland, Homburg/Saar - Germany
4. Institute for Clinical and Experimental Surgery, University of Saarland, Homburg/Saar - Germany