SEM Survey of Human, Shark, and Rodent Teeth

James Yuzawa
University of Rochester, Department of Computer Science
Rochester, NY 14627 -

Shark Teeth

These samples were obtained at a specialty store and gift shop in Destin, FL in early 2014. The teeth had their bony roots still attached.


Figure 8: SE2 detector. The very tip of the shark tooth. There is minimal wear at the tip.
Figure 9: False-color image of a broken section of shark tooth. SE2 image is yellow and background. InLens is orange. A minimally worn surface of enamel is visible near the fracture. The fracture reveals that the enamel layer is quite thin at only a few hundred microns. Beneath the thin layer of enamel is the spongy dentin.

Inner Tissue

Figure 10: InLens detector. A frontal cross section of the interior of the tooth near the tip. This tissue is very spongy and filled with open spaces. The dark areas are the voids in the material. Inside the spongy structure are small particles. It is unclear whether this is dentin or some remnant of the pulp.

Figure 11: InLens detector. An inset of Figure 10.
Figure 12: Image analysis done in ImageJ on part of Figure 11. Care was taken only to identify the particles in the tissue and not the voids.

The ImageJ data found 33 particles. The average area was 0.171 μm2 with a standard deviation of 0.108. The average Feret diameter of a hole was 0.599 μm with a standard deviation of 0.195.


Figure 13: The EDS results for the shark tooth. Calcium, phosphorus, carbon, and oxygen are all present as expected. There are possibly peaks for sodium and fluorine.