[1] Univ Klinikum Dusseldorf, Dept Oral Surg, Dusseldorf, Germany
[2] Univ Complutense Madrid, Fac Odontol, Madrid, Spain
[3] Rhein Westfal TH Aachen, Fac Med, Ctr Implantol, Dept Prosthodont & Biomat, Pauwelsstr 30, D-52074 Aachen, Germany
[4] Univ Connecticut, Sch Dent Med, Dept Reconstruct Sci, Farmington, CT 06032 USA
[5] Camlog Fdn, Basel, Switzerland