1. Department of Restorative Dentistry, Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, MB R3E 0W3, Canada
2. Director Advanced Prosthodontics Residency Program, College of Dentistry, The Ohio State University, Columbus, OH 43210, USA
3. Department of Prosthodontics, College of Dentistry and Dental Clinics, The University of Iowa, Iowa City, IA 52242, USA
4. Missouri School of Dentistry & Oral Health, A.T. Still University, Kirksville, MO 63501, USA