1. The Ohio State University Department of Materials Science and Engineering, , Columbus, OH, USA
2. Ohio State University College of Dentistry Division of Biosciences, , Columbus, OH, USA
3. University of Michigan School of Dentistry Department of Biologic and Materials Sciences, , Ann Arbor, MI, USA
4. McGill University Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, , Montreal, QC, Canada
5. Center for Electron Microscopy and Analysis, The Ohio State University , Columbus, OH, USA