Keratin extracted from sheep's wool repairs teeth in breakthrough

Dental treatments from sheep’s wool and other hair could be used to coat teeth to repair enamel and prevent tooth decay, according to a new study.

After extracting keratin — a protein found in hair, skin and fingernails — from wool and applying it to teeth, scientists found that the substance formed a protective crystal-like coating that mimicked natural tooth enamel.

The finding could support sustainable, low-cost treatments for early tooth decay within the next two to three years, according to the researchers.They reported their findings August 12 in the journal Advanced Healthcare Materials.

"Keratin offers a transformative alternative to current dental treatments," study coauthor Sara Gamea, a dentistry researcher at King's College London, said in the statement. "Not only is it sustainably sourced from biological waste materials like hair and skin, it also eliminates the need for traditional plastic resins, commonly used in restorative dentistry, which are toxic and less durable. Keratin also looks much more natural than these treatments, as it can more closely match the color of the original tooth."

Untreated tooth decay is the world's most common oral health condition, affecting some 2 billion people worldwide. Over time, acidic foods, poor oral hygiene, and everyday wear and tear can break down the protective enamel that covers a person's teeth. Losing that enamel can lead to pain, cavities and tooth loss.

"Unlike bones and hair, enamel does not regenerate," study coauthor Sherif Elsharkawy, a researcher specializing in prosthodontics at King's College London, said in a statement. "Once it's gone, it's lost forever."

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To investigate whether keratin-based treatments could help stop tooth decay and repair enamel, Elsharkawy and his colleagues first extracted keratin from wool fibers. Then they mixed the keratin with water, where it formed a thin film.

After applying the keratin film to a tooth sample, the scientists found that it formed an ordered, strong and crystal-like coating similar to biological enamel when it came in contact with minerals in saliva. Over the course of a month, the coating attracted calcium and phosphate ions, building up a hard, protective layer over the tooth.

The scientists are exploring ways to bring the keratin treatment to the public. Keratin toothpastes for daily use or professional coatings applied at a dentist's office could be available within the next few years, according to the statement.

"We are entering an exciting era where biotechnology allows us to not just treat symptoms but restore biological function using the body's own materials," Elsharkawy said. "With further development and the right industry partnerships, we may soon be growing stronger, healthier smiles from something as simple as a haircut."