[1] Univ Int Catalunya, Dept Periodontol, C Josep Trueta S-N, Barcelona 08195, Spain
[2] Univ Michigan, Sch Dent, Dept Periodont & Oral Med, Ann Arbor, MI 48109 USA
[3] Univ Ferrara, Res Ctr Study Periodontal & Periimplant Dis, Oral Surg, Ferrara, Italy
[4] Azienda Unita Sanitaria Locale AUSL, Operat Unit Dent, Ferrara, Italy
[5] Goethe Univ Frankfurt, Dept Oral Surg & Implantol, Frankfurt, Germany
[6] Kristianstad Univ, Dept Hlth Sci, Kristianstad, Sweden
[7] Univ Bern, Sch Dent Med, Dept Periodontol, Bern, Switzerland
[8] Copenhagen Univ Hosp, Rigshosp, Dept Oral & Maxillofacial Surg, Copenhagen, Denmark
[9] Univ Ferrara, Res Ctr Study Periodontal & Periimplant Dis, Ferrara, Italy
[10] Univ Ferrara, Res Ctr Study Periodontal & Periimplant Dis, Periodontol, Ferrara, Italy