1. Department of Restorative Dentistry, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
2. Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Aurora, CO, USA
3. Department of Dental Materials, School of Dentistry, University of São Paulo, Brazil
4. Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, 875 Union Avenue, Memphis, TN 38163, USA