[1] Univ Torino, Div Maxillofacial Surg, Turin, Italy
[2] Univ Michigan, Dept Periodont & Oral Med, Ann Arbor, MI USA
[3] Univ Bern, Sch Dent Med, Dept Periodontol, Freiburgstr 7, CH-3010 Bern, Switzerland
[4] Copenhagen Univ Hosp, Rigshosp, Dept Oral & Maxillofacial Surg, Copenhagen, Denmark
[5] Univ Bern, Sch Dent Med, Dept Restorat Pediat & Prevent Dent, Bern, Switzerland
[6] Univ Pisa, Dept Surg Med & Mol Pathol & Crit Care Med, Pisa, Italy
[7] Univ Hosp Pisa, Subunit Periodontol Halitosis & Periodontal Med, Pisa, Italy
[8] Univ Siena, Dept Med Biotechnol, Unit Periodontol Endodontol & Restorat Dent, Siena, Italy
[9] Julius Maximilians Univ Wurzburg, Dept Periodontol, Wurzburg, Germany