The King’s College London team of scientists discovered that keratin produces a protective coating that mimics the structure and function of natural enamel when it comes into contact with minerals in saliva. In a new study published today, scientists discovered that keratin, a protein found in hair, skin and wool, can repair tooth enamel and stop early stages of decay. Unlike bones and hair, enamel does not regenerate, once it is lost, it’s gone forever. The treatment could be delivered through a toothpaste for daily use or as a professionally applied gel, similar to nail varnish, for more targeted repair. In their study, published in Advanced Healthcare Materials, the scientists extracted keratin from wool.