Study finds iron-rich enamel protects, but doesn't color, rodents' orange-brown incisors

Chattering squirrels, charming coypus, and tail-slapping beavers -- along with some other rodents -- have orange-brown front teeth. Researchers have produced high-resolution images of rodent incisors, providing an atomic-level view of the teeth's ingenious enamel and its coating. They discovered tiny pockets of iron-rich materials in the enamel that form a protective shield for the teeth but, importantly, don't contribute to the orange-brown hue -- new insights that could improve human dentistry.