1. Department of Operative Dentistry and Periodontology, Dental School and Hospital, University Freiburg Medical Centre, Freiburg, Germany.
2. Department of Oral Biotechnology, Dental School and Hospital, University Freiburg Medical Centre, Freiburg, Germany.
3. Department of Medical Biometry and Statistics, Institute of Medical Biometry and Medical Informatics, University Freiburg, Freiburg, Germany.
4. Department of Oral and Maxillofacial Surgery, Dental School and Hospital, University Freiburg Medical Centre, Freiburg, Germany.