1. Visiting Assistant Professor, Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota School of Dentistry, Minneapolis, MN, and Assistant Lecturer of Dental Materials, Faculty of Dentistry, Mansoura University, Egypt.
2. Professor, Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota School of Dentistry, Minneapolis, MN.
3. Senior Research Associate, Division of Biostatistics and School of Dentistry, University of Minnesota, Minneapolis, MN.