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