[1] Northern Hessia Implant Ctr, D-34369 Hofgeismar, Germany
[2] Univ Med Ctr Goettingen, Dept Prevent Dent Periodontol & Cariol, Gottingen, Germany
[3] Univ Med Ctr Goettingen, Dept Prevent Dent Periodontol & Cariol, Periodontol Sect, Gottingen, Germany
[4] UniversityMed Ctr, Inst Med Biometry & Med Informat, Dept Med Biometry & Stat, Freiburg, Germany
[5] Univ Freiburg, Sect Dept Operat Dent & Periodontol, D-79106 Freiburg, Germany