1. Research Fellow, Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece.
2. Director, Dental Biomaterials Research and Development Chair, and Professor, Prosthetic Dental Sciences Department, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
3. Professor and Director, Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
4. Associate Professor, Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece, and Consultant, Dental Biomaterials Research and Development Chair, King Saud University, Riyadh, Saudi Arabia.