[1] Univ Bern, Sch Dent Med, Dept Periodontol, Freiburgstr 7, CH-3010 Bern, Switzerland
[2] Copenhagen Univ Hosp, Rigshosp, Dept Oral & Maxillofacial Surg, Copenhagen, Denmark
[3] Ctr Clin Res & Evidence Synth Oral Tissue Regenera, Boston, MA USA
[4] Univ Siena, Dept Med Biotechnol, Unit Periodontol Endodontol & Restorat Dent, Siena, Italy
[5] Univ Torino, Div Maxillofacial Surg, Turin, Italy
[6] Univ Michigan, Dept Periodont & Oral Med, Ann Arbor, MI USA