1. Department of Prosthodontics and Implantology, University of La Salle Bajio School of Dentistry, Leon 37150, Mexico
2. Division of Operative Dentistry, Department of General Dentistry, The University of Tennessee Health Science Center, College of Dentistry, Memphis, TN 38103, USA
3. Division of Dental Biomaterials, The University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35233, USA
4. Department of Orthodontics, University of La Salle Bajio School of Dentistry, Leon 37150, Mexico
5. Department of Prosthodontics, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52241, USA
6. Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota School of Dentistry, Minneapolis, MN 55455, USA
7. Department of Operative Dentistry, School of Dentistry, Aichi Gakuin University, Nagoya 464-8651, Japan
8. Department of Operative Dentistry, University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA 52242, USA
9. Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE 68102, USA