1. Clinic of Reconstructive Dentistry, Center of Dental Medicine University of Zurich Zurich Switzerland
2. Department of Life, Health and Environmental Sciences University of L'Aquila L'Aquila Italy
3. Center for Clinical Research and Evidence Synthesis in Oral TissuE RegeneratION (CRITERION) Ann Arbor Michigan USA
4. Center for Clinical Research and Evidence Synthesis in Oral TissuE RegeneratION (CRITERION) Boston Massachusetts USA
5. Department of Oral Medicine, Infection, and Immunity, Division of Periodontology Harvard School of Dental Medicine Boston Massachusetts USA
6. Department of Periodontics and Oral Medicine University of Michigan School of Dentistry Ann Arbor Michigan USA