"Toothpaste made from... hair?" Keratin creates an enamel-like shield on teeth and repairs early damage

Scientists from King's College London have shown that keratin, the protein that hair, skin and wool are made of, can serve as a "framework" for natural-like enamel mineralization. When such a keratin film comes into contact with minerals in saliva, an ordered, enamel-like layer grows on the tooth surface, which restores the appearance and hardness of early damaged enamel (for example, white spots) and reduces sensitivity. The authors are already discussing two formats: a daily paste and a professional gel, with keratin from "bio-waste" (hair/wool) serving as the raw material.

Background

What are already available from clinical/office alternatives for early defects:

1. Fluorides, CPP-ACP (caysin phosphopeptide + amorphous calcium phosphate) - increase salivary ion saturation and help remineralize white spots, but the effect is compliance dependent and inconsistent between studies.
2. Bioactive glasses (NovaMin) and nano-hydroxyapatite are popular, but for some formulas there is less clinical evidence than for fluorides; results are often in vitro.
3. Self-assembling peptides (P11-4) form a fibrillar seed matrix in enamel; there is randomized and clinical evidence for remineralization of early lesions and enhancement of the effect of fluoride.
4. Resin infiltration (Icon) - microinvasively "fills" the porous layer and stabilizes white spots, but this is a polymer filling, not true mineralization.

• Why enamel needs to be “repaired from the outside”. Dental enamel is almost 96% hydroxyapatite and after eruption it cannot self-repair: building cells (ameloblasts) are lost, so classic fillings only cover the defect, but do not restore the natural structure. Hence the interest in materials that trigger mineralization on the surface due to saliva ions - that is, they act “like nature”.
• What is biomimetic remineralization? These are approaches where the material serves as a template/scaffold for the deposition of calcium and phosphate into an enamel-like lattice. In recent years, organic and inorganic platforms have been tested: from nanomaterials and peptides to enamel matrix "prostheses". The idea is not just to "seal" the pores, but to build up an ordered mineral that is close in optics and mechanics to enamel.
• Where is the keratin (hair/wool) here and what is new? In their new work, the team from King's College London showed that a thin keratin film adheres well to enamel and binds ions from saliva, triggering the growth of an ordered enamel-like layer. On model "white spots", the coating restored optics and hardness - essentially acting as a bio-template, not a cosmetic varnish. Plus - sustainable raw materials: keratin from "bio-waste" (hair/wool).
• Why it makes sense from a materials science perspective. Keratin is a protein with rich surface chemistry; in tissue engineering it has already been mineralized (for bone regeneration) and used as a cheap, accessible carrier. Transferring it to dentistry offers a chance to combine adhesion to enamel and self-organization of the mineral in the oral cavity (saliva as a constant source of ions).
• How does the keratin approach compare to its “competitors”? Unlike resins and infiltrants, keratin does not seal with a polymer, but builds up the mineral; unlike simple “ionic” pastes (fluoride, nano-HA), it provides an organizing matrix. In essence, it is closer to peptide matrices (P11-4), but potentially cheaper and technologically simpler. The field as a whole is moving toward self-assembling and matrix systems (see reviews on “next-gen” remineralization).
• Limitations to remember: Results are in vitro/models so far; oral testing (brush wear, acids/alkalis, microbiota, color fastness), standardization of keratin sources, and regulatory issues are ahead. To routine pastes/gels - only if clinical trials confirm durability and safety.
• The big picture. Biomimetic remineralization is the real “next step” between prevention and drilling: template + saliva ions → enamel-like layer. Keratin is another candidate in this line, which, if clinically successful, could complement the arsenal of early lesions and sensitivity treatments.

How does this work

Enamel is a super-hard tissue and does not heal on its own. The team's idea: to give the tooth a biomimetic "template". Keratin is a flexible, "disordered" protein, it adheres well to enamel and binds calcium and phosphate. They applied a thin film of keratin - and then saliva does the rest: ions gradually settle on the film, line up in a crystalline lattice similar to natural enamel, forming a dense protective layer. This is not a resin filling, but a mineralized coating related to natural tissue.

What exactly did they do?

• The researchers isolated keratin from wool/hair and applied it to the surface of teeth in a laboratory model of early enamel destruction (white spot lesions).
• In the presence of salivary minerals, the keratin film was mineralized: a highly organized “enamel-like” layer was formed.
• Based on the results of the assessments, the authors report the restoration of optical (the appearance of “healthy” enamel) and mechanical properties (hardness, resistance to acid) of early defects.

Why is this important?

• Early carious lesions (white matte spots, sensitivity) are a huge layer of dentistry. Now we mainly slow down the process with fluorides/resin infiltrators. The keratin approach offers precisely the restructuring of the mineral with support from saliva - a more "biological" scenario.
• Colour stability and aesthetics. The enamel-like layer is optically closer to natural tissue than plastic resins; this is especially valuable in “visible” areas.
• Ecology and availability. Keratin can be obtained from hair/wool - essentially from bio-waste, which reduces dependence on plastics and chemical resins.

What it means for life (if the technology reaches the dentist's chair)

• Home format: regular paste with keratin, which under the raw flow of saliva gradually builds up a protective layer and seals open dentinal tubules (less “shooting” from the cold).
• In-office format: gel coating "like nail polish" - for accelerated/targeted repair of white spots and sensitive areas. According to the authors, in partnership with the industry, products may appear in 2-3 years (these are plans, not a guarantee).

How does the new coating differ from the “classic”?

• It does not mask, but mineralizes. Unlike composites and resin infiltrants, the keratin platform initiates mineralization, and does not simply fill the defect with a polymer.
• Works together with saliva. What usually hinders the adhesive (moisture) helps here - a source of ions for growth.
• Potentially more durable. The enamel-like layer should hold up better to acid attacks than organic resins. (Clinical trials will show this for sure.)

Restrictions

• For now, it's a laboratory. We're talking about in vitro/model tests. In the clinic, the layer is exposed to brushes, food, acid/alkali cycles, and microbiota — we need to test durability and safety in humans.
• Raw material sources. Keratin can be of animal/human origin - questions of standardization, allergies, ethics and regulation lie ahead.
• Not a "magic pill". Medium and deep caries, chips, cracks still require fillings/inlays and a dentist. The keratin approach is about early lesions and prevention.

What's next?

The team is already advancing the technology into practice (formulations, stability, “application modes,” pilot tests). If clinical data confirms laboratory data, dentists will have a new class of coatings — biotemplates that grow their own “enamel” from what is already in our mouths — saliva.

Source: Gamea S. et al. Biomimetic Mineralization of Keratin Scaffolds for Enamel Regeneration. Advanced Healthcare Materials, 2025. DOI: 10.1002/adhm.202502465