1. Department of Graduate Periodontics, Multidisciplinary Educational Center in Oral Rehabilitation (CEMRO), Tarímbaro 58893, Mexico
2. Department of Prosthodontics, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA
3. Department of Restorative Dentistry, Gerald Niznick College of Dentistry, University of Manitoba, Winnipeg, MB R3E 3N4, Canada
4. Private Dental Technician, Irapuato 36643, Mexico
5. Division of Restorative Dental Sciences, Clinical Sciences Department, Ajman College of Dentistry, Ajman City P.O. Box 346, United Arab Emirates
6. Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland
7. Missouri School of Dentistry & Oral Health, A.T. Still University, Kirksville, MO 63501, USA