 - Adult patients at least 18 years of age with moderate to severe periodontal disease chronic and aggressive periodontitis to be recruited from the Dept. of Periodontology, Centre for Dental, Oral, and Maxillofacial Medicine, Hospital of the Johann Wolfgang Goethe-University FrankfurtMain and from the Section of Periodontology, Dept. of Conservative Dentistry, Clinic for Oral, Dental, and Maxillofacial Diseases, University Hospital Heidelberg 