Scientists have created a new synthetic material with the properties of tooth enamel, setting the stage for advances in tooth repair or replacement (Nature 2017, DOI: 10.1038/nature21410). Tooth enamel from all species has a similar structure: microsized ceramic columns in a soft protein matrix. An international team led by Nicholas A. Kotov of the University of Michigan, Ann Arbor, prepared arrays of micrometer-scale zinc oxide columns to form “nanowire carpets.” Then the researchers embedded the columns in a polyallylamine matrix. They built up the material by repeating the process, adding more layers of the polymer-impregnated columns on top of each other. The material has a collection of properties—stiffness, density, and vibrational damping—that are similar to or better than those of tooth enamel and that haven’t been combined in one synthetic material before. More work needs to be done to scale up to the size of teeth without defects. But, the