An advanced imaging technique called scanning transmission electron microscopy (STEM) has provided scientists with some rough pictures of enamel crystallites. However, the intensity of traditional STEM beams required for a clearer view would damage the enamel before a picture could be generated.
In new research, a team used a combination of advanced imaging techniques to produce a picture of enamel down to the atomic level. These techniques include a version of STEM performed at very cold temperatures and atomic probe tomography, which takes pictures of substances one layer of atoms at a time. The methods revealed a high-definition view of the crystallites, which are made mostly of a mineral known as hydroxylapatite. They also revealed the patterns in which other minerals were deposited within the crystals, including magnesium, sodium, and fluoride.
The mineral deposits may also explain some of the risks of dental caries. When the researchers exposed teeth to acid and then examined the resulting damage, the enamel crystal cores showed more erosion than the shells. The team is planning further studies to understand more about this process.