[1] Univ N Carolina, Dept Prosthodont, Chapel Hill, NC 27599 USA
[2] Univ N Carolina, Dept Oral & Maxillofacial Surg, Chapel Hill, NC 27599 USA
[3] Univ Ghent, Sch Dent, Dept Periodontol & Oral Implantol, Fac Med & Hlth Sci, B-9000 Ghent, Belgium
[4] Univ Int Catalunya, Dept Prosthodont, Sch Dent, Catalunya, Spain
[5] Univ Int Catalunya, Res Dept, Sch Dent, Catalunya, Spain
[6] Univ Schleswig Holstein, Dept Oral & Maxillofacial Surg, Lubeck, Germany
[7] Univ Kiel, Sch Dent, Dept Prosthodont Propaedeut & Dent Mat, Kiel, Germany
[8] Univ Ghent Belgium, Dept Periodontol & Oral Implantol, Fac Med & Hlth Sci, Sch Dent, Ghent, Belgium
[9] Univ Malmo, Dept Prosthodont, Malmo, Sweden