[1] Univ Munster, Sch Dent, Cent Interdisciplinary Ambulance, Albert Schweitzer Campus 1,Bldg W 30, D-48149 Munster, Germany
[2] Dent Clin Bochum, Dent Phobia Therapy Ctr, Bochum, Germany
[3] Univ Witten Herdecke, Ctr Dent Oral & Maxillofacial Surg, Witten, Germany
[4] Univ Bern, Dept Reconstruct Dent & Gerodontol, Bern, Switzerland
[5] Univ Bonn, Dept Prosthodont Preclin Educ & Dent Mat Sci, Bonn, Germany