1. Department of Periodontology, Endodontology and Cariology; Center of Dental Traumatology; University Center for Dental Medicine; University of Basel; Basel Switzerland
2. Department of Restorative Dentistry, Periodontology, Endodontology and Pediatric Dentistry; School of Dental Medicine; Eberhard Karls University; Tübingen Germany
3. Department of Oral Surgery, Oral Radiology and Oral Medicine; Center of Dental Traumatology; University Center for Dental Medicine; University of Basel; Basel Switzerland
4. Department of Operative Dentistry and Periodontology; Center of Dental Traumatology; University of Würzburg; Würzburg Germany