1. Section Parodontologie; C1 Centre Médico-Dentaire; Geneva Switzerland
2. Department of Implantology and Periodontology; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands
3. Department of Prosthodontics and Biomaterials; Danube Private University; Krems Austria
4. Private Practice; Forchheim Germany
5. Department of Prosthetic Dentistry; Private Dental Clinic; Aachen Germany
6. Department of Biomaterials; Radboud University Nijmegen Medical Centre; Nijmegen The Netherlands