1. Department of Preventive Dentistry, Periodontology and Cariology; Center for Dental Medicine; University of Zurich; Zurich Switzerland
2. Department of Dental Materials Science; Academic Centre for Dentistry Amsterdam (ACTA); University of Amsterdam and VU University Amsterdam; Amsterdam the Netherlands
3. Department of Operative Dentistry and Periodontology; University of Regensburg; Regensburg Germany
4. Division of Cariology and Endodontology; School of Dentistry; University of Geneva; Geneva Switzerland