[1] Steinbeis Univ, Berlin, Germany
[2] Univ Cologne, Dept Oral & Craniomaxillofacial Plast Surg & Inte, Dept Oral Surg & Dent Implantol, Cologne, Germany
[3] Augusta Univ, Dent Coll Georgia, Restorat Sci, Augusta, GA USA
[4] Univ Calif Los Angeles, Sch Dent, Oral & Maxillofacial Surg Restorat Dent, Los Angeles, CA USA
[5] Univ Penn, Sch Dent Med, Dept Periodont, Philadelphia, PA USA
[6] Univ Penn, Sch Dent Med, Dept Prevent & Restorat Sci, Philadelphia, PA USA