A team of scientists in London may have found a way to repair tooth enamel using an ingredient found in an unexpected place.

Researchers at King’s College London experimented with keratin on teeth. Keratin is the same natural protein found in hair, skin and nails. In lab tests, the system has shown potential in repairing early defective dental enamel lesions, restoring both optical appearance and mechanical properties.

This discovery potentially offers a future in reversing cavities.

Daily habits like sipping acidic drinks or skipping proper brushing gradually erode enamel, causing sensitivity and tooth loss according to the study. While fluoride can only slow the damage, the keratin-based formula in the new study stopped it entirely in lab tests.

Researchers harvested keratin from wool and found that it forms a crystal-like structure upon application to the tooth surface and exposure to minerals in saliva.

Over time, this structure attracted calcium and phosphate and turned them into a durable layer that mimics enamel. By forming a dense mineral layer that seals nerve pathways, keratin shields teeth from further wear and relieves sensitivity at the same time according to the findings.

The regenerated material could protect teeth against further acid wear according to the research team. The process might even reverse early decay before it becomes a serious problem requiring expensive dental work.

What makes this discovery especially appealing is its potential for sustainability. Keratin can be harvested from hair or wool that would otherwise be discarded, turning waste into a valuable health product.

In the press announcement, King’s College London scientists said they envision it being added to everyday toothpaste or used in dentist-applied treatments within the next few years. However, that timeline depends on further testing and commercial development.

Experts caution that this breakthrough is still in its early stages.

“Only limited enamel thickness was regenerated, along with questionable biocompatibility.”

The study also notes that the clinical applicability of this technique is challenging due to the complicated fabrication process.

That means questions remain about the scalability of the solution in widespread application.

According to the researchers, more work is needed to understand how thick and durable the new enamel layer can become and whether it can withstand years of real-world wear. Teeth endure constant stress from chewing, temperature changes and acidic foods.

Independent dental scientists have also noted that lab-based enamel regeneration studies often struggle to match the complexity of true enamel. What works in a laboratory setting does not always translate to success inside a human mouth.

Enamel is the hardest substance in the human body, but it cannot naturally regrow once it is damaged. Traditional toothpastes and fluoride treatments only help slow decay or strengthen what remains. If the keratin-based method proves effective in people, experts say it could mark a major step toward truly regenerative dentistry.

The study was published in the journal Advanced Healthcare Materials.

Dental problems affect millions of Americans who struggle to afford expensive treatments like fillings, crowns and root canals. A toothpaste or simple treatment that could actually reverse early decay would be revolutionary for people who cannot afford regular dental care.

The connection between oral health and overall health has become increasingly clear in recent years. Gum disease has been linked to heart problems, diabetes complications and other serious conditions. Finding better ways to protect teeth could have benefits far beyond just preventing cavities.

Using waste materials like discarded hair or wool to create medical treatments aligns with growing interest in sustainable health solutions. Rather than relying on synthetic chemicals, this approach uses natural proteins the body already recognizes.

The researchers at King’s College London continue working to refine their technique and address the limitations identified in early testing. If they succeed in overcoming the challenges of scalability and durability, this discovery could fundamentally change how dentists treat tooth decay.

For now, maintaining good oral hygiene through regular brushing, flossing and limiting acidic foods remains the best defense against enamel erosion. But the future may bring options that go beyond prevention to actual repair of damaged teeth.