[1] Ernst Moritz Arndt Univ Greifswald, Unit Periodontol, Ctr Oral Hlth, D-17475 Greifswald, Germany
[2] Ernst Moritz Arndt Univ Greifswald, Unit Prosthodont Gerodontol & Biomat, Ctr Oral Hlth, D-17475 Greifswald, Germany
[3] Ernst Moritz Arndt Univ Greifswald, Inst Community Med, D-17475 Greifswald, Germany