1. Department of Periodontics, Dental Implants Research Center, Dental Research Institute, School of Dentistry, Isfahan University of Medical Sciences, 81658 Isfahan, Iran
2. Department of Oral Surgery and Orthodontics, University Clinic of Dental Medicine and Oral Health, Medical University of Graz, Graz 8010, Austria
3. Clinic of Conservative and Preventive Dentistry, Division of Periodontology & Peri-Implant Diseases, Center of Dental Medicine, University of Zurich, Plattenstrasse, 11 8032 Zurich, Switzerland