1. Department of Prosthodontics, TUFTS University School of Dental Medicine, Boston, MA, USA
2. Department of Periodontology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
3. Department of Restorative Dentistry, University of Washington School of Dentistry, Seattle, WA, USA
4. Biostatistics, Joseph J Zilber School of Public Health, University of Wisconsin, Milwaukee, WI, USA
5. Department of Materials Science & Engineering, University of Washington School of Engineering, Seattle, WA, USA