A new study from King’s College London suggests that keratin—the protein found in human hair, skin and wool—can regenerate tooth enamel and potentially halt early tooth decay.
Published in Advanced Healthcare Materials, the research found that keratin—when extracted from wool and applied to teeth—forms a crystal-like layer that mimics and rebuilds lost enamel.
The study presents keratin as an eco-friendly, biomimetic alternative to traditional fluoride treatments, which can only slow decay, but not reverse it.
“Enamel is the hardest tissue in the body, but unlike bone or skin, it cannot repair itself once damaged,” Dr. Sherif Elsharkawy, senior author and prosthodontics consultant at King’s College London, told Newsweek in an email.
“Dentistry has relied for decades on synthetic materials such as plastic resins or ceramics, but these are never a perfect biological match.
“I wanted to find a natural, sustainable material that could actually regenerate enamel rather than simply cover damage.”
Photo by Fizkes / Getty Images
Why It Matters
Tooth enamel erosion is irreversible and widespread, and it can be caused by a combination of factors.
Acidic foods and drinks—such as soda, citrus and vinegar—erode enamel by lowering the pH in the mouth, which dissolves the minerals that keep teeth hard.
Poor oral hygiene allows plaque bacteria to produce acids that contribute to decay, while aggressive brushing can physically wear away the enamel surface.
Age also plays a role, as enamel naturally thins over time, exposing the softer dentin underneath.
Conditions like acid reflux, dry mouth and eating disorders can accelerate enamel loss as well by increasing acid exposure or reducing saliva, which normally helps neutralize harmful acids.
Once tooth enamel is lost, the tooth nerves are exposed, which is painful and makes the teeth sensitive.
While fluoride toothpastes are standard for managing this issue, keratin offers a regenerative approach that goes beyond symptom control.
What to Know
Researchers used wool as a keratin source and applied it to teeth in a laboratory.
“Keratin has a molecular structure that can guide minerals into forming enamel-like crystals,” Elsharkawy told Newsweek.
“Turning waste materials, mainly sheep wool, into a tooth-repair material felt both scientifically exciting and environmentally meaningful.”
The treatment is versatile, according to Elsharkawy.
“Keratin can be transformed into a material as strong and functional as natural enamel,” he explained.
“It could be delivered through something as simple as toothpaste or as a professional in-clinic gel, making tooth-decay repair accessible, affordable, and sustainable worldwide.”
What People Are Saying
“We knew keratin had promise, but I was impressed by how precisely it guided crystal growth into enamel-like structures,” Elsharkawy said.
“It did not just coat the tooth—it recreated the highly ordered crystal pattern of natural enamel, something that normally only happens during tooth development.”
What’s Next
The team is working on commercial pathways for the treatment, with Elsharkawy noting, “The response has been enormous from dentists, industry, and the public.”
He added that the group had launched the company Eterna Regeneratives to lead the translation of this breakthrough.
“The dental industry already sees this as a game-changing innovation,” he explained.
“Our first go-to-market products will be toothpaste and mouthwash for daily use, followed by a more potent professional treatment for those at higher risk of decay. […]
“We are confident this will be available to the public within two years.”