[1] Univ Milan, Sch Med, Post Grad Sch Oral Surg, Oral Surg & Implant Dept,Fdn IRCCS Policlin Ca Gr, Milan, Italy
[2] Univ Bristol, Dent Hosp & Sch, Bristol, Avon, England
[3] Univ Ulm, Ctr Dent, Dept Prosthet Dent, D-89069 Ulm, Germany
[4] Inst Postgrad Dent Educ, Dept Prosthet Dent, Jonkoping, Sweden
[5] Univ Copenhagen Hosp, Dept Oral & Maxillofacial Surg, DK-2100 Copenhagen, Denmark
[6] Univ Granada, Oral Surg & Implant Dent Dept, Sch Dent, Granada, Spain