Researchers at King's College London have shown that keratin, the protein found in hair, skin, and wool, can repair and protect tooth enamel by forming a mineralised layer on the tooth surface. The study, published in Advanced Healthcare Materials, found that when keratin is applied to teeth and exposed to minerals in saliva, it organises into a crystal-like structure that mimics natural enamel, attracting calcium and phosphate ions to build a durable protective layer over time.

Enamel cannot regenerate once lost, making this finding relevant to a large patient population affected by erosion, sensitivity, and early decay. In laboratory tests, the keratin-based formulation outperformed fluoride by completely preventing erosion rather than slowing it. It also blocked the dentinal tubules responsible for sensitivity, addressing both structural damage and patient discomfort.

The research team expects keratin-based products to reach consumers within two to three years, either as a daily toothpaste or a professional gel applied in-clinic, comparable to a varnish treatment. Keratin can be sourced from biological waste such as hair clippings, which makes it cheaper to produce than synthetic resins and free of the toxicity concerns associated with plastic-based restoratives. For dentists, this could mean a remineralising agent that is biocompatible, aesthetically close to natural tooth colour, and suitable for both preventive and early-intervention use.