 Patients From April 2007 until February 2009 all patients undergoing periodontal treatment at the Department of Periodontology, Center of Dental, Oral, and Maxillofacial Medicine Carolinum, Johann Wolfgang Goethe-University FrankfurtMain and the Section of Periodontology, Department of Conservative Dentistry, Clinic for Oral, Dental and Maxillofacial Diseases, University Hospital Heidelberg are screened for this study. Patients and methods of this study have been described in detail before. Thus only a brief description is provided. 