1. Faculty of Dental Medicine, Universidade Católica Portuguesa, 3504-505 Viseu, Portugal
2. Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, 305 W 12th Ave., Columbus, OH 43210, USA
3. Center for Interdisciplinary Research in Health, Faculty of Dental Medicine, Universidade Católica Portuguesa, 3504-505 Viseu, Portugal
4. Independent Researcher, St. Louis, MO 63104, USA
5. Missouri School of Dentistry & Oral Health, A. T. Still University, 1500 Park Ave., St. Louis, MO 63104, USA