Despite appearances, this isn’t an elegantly woven basket or a soft, downy feather: it is an extreme close-up – taken with a scanning electron microscope – of the hardest substance in the mammalian body—tooth enamel.
This exquisitely detailed image was generated by Olivier Duverger and Maria Morasso of US National Institute of Arthritis and Musculoskeletal and Skin Diseases. Before placing a sample of mouse dental enamel under the microscope, they treated it briefly with acid to reveal how the tissue’s mineralized rods are interwoven in a manner that gives teeth both strength and flexibility.
The researchers are among those working to solve a longstanding mystery: how exactly does dental enamel, which starts out as a soft, lattice-like organic matrix in the early stages of tooth development, end up as the hard, mineralized tissue that covers our teeth? Recently, they uncovered unexpected links between structural elements in dental enamel and hair. It turns out that a specific hair keratin is also an important component in the sheath surrounding the enamel’s rods. As a result, people with an inherited hair disorder caused by a mutation in the gene that codes for this keratin also have weakened dental enamel, and are particularly prone to tooth decay.