Gel That Regrows Tooth Enamel: What Patients Should Know

Short answer

• No gel that a patient can buy today, and no gel your dentist can apply at a routine visit today, regrows a lost layer of tooth enamel. That headline belongs to laboratory research, not to patient care. In laboratories, researchers really have grown thin layers of new enamel like crystals on damaged tooth surfaces, and that work is published, peer reviewed, and genuinely interesting. It is also thin, slow, and untested as a routine treatment in people. None of it has become a product or a procedure you can ask for. What does exist today is remineralization. When enamel has lost minerals but its surface is still intact, minerals from saliva and fluoride can move back into it and make it harder and more resistant to acid. The National Institute of Dental and Craniofacial Research (NIDCR) describes this early stage, often marked by a white spot, as the point where decay can be stopped or reversed. Once the surface has broken down into a cavity, the picture changes. NIDCR calls a cavity permanent damage that a dentist has to repair with a filling, and no gel, paste, or rinse changes that. This article is general information only, not a diagnosis or a treatment plan for your teeth. If you have pain, swelling, a visible hole, a broken tooth, or sensitivity that lingers, see a dentist promptly rather than waiting for a future product.

What Tooth Enamel Is and Why It Does Not Grow Back

Enamel is the hard outer covering of the crown of a tooth, and it is the hardest tissue in the human body. Researchers at Zhejiang University, whose enamel work is covered below, put its mineral content at about 96 percent. That mineral is hydroxyapatite, a crystalline form of calcium phosphate, arranged in tightly packed rods. The remaining fraction is water and a small amount of organic material. Because enamel is almost all mineral, it can withstand years of biting and chewing. Because it contains no living cells, it cannot heal the way living tissue heals.

That second point is the one that matters most for this topic. Enamel is built before a tooth emerges, by specialized cells called ameloblasts. Those cells lay down a protein scaffold, guide the crystals as they form, and are then lost as the tooth erupts. After that, there is no cell left in or on the tooth that can make new enamel. Bone is different, because bone keeps living cells throughout life and remodels itself after a break. Enamel has no equivalent system. When enamel is worn away by acid, grinding, or decay, the thickness that is gone does not return on its own.

Damage also arrives by different routes, and the route affects what can be done. Decay starts when bacteria in plaque use sugars and starches to make acid, and that acid pulls minerals out of enamel. Erosion is a direct chemical attack, usually from acidic drinks, frequent reflux, or vomiting. Wear comes from grinding, clenching, hard brushing, or biting on hard objects. All three can thin enamel, but only the earliest mineral loss, while the surface is still whole, can be partly reversed. Lost thickness, from any cause, cannot be brushed back.

Remineralization Is Not Regrowth

Much of the confusion around enamel products comes from two words being treated as if they meant the same thing. They do not.

Remineralization means minerals returning to enamel that is still present. NIDCR describes teeth as going through a daily tug of war: acids from plaque bacteria strip calcium and phosphate out of enamel, while saliva, helped by fluoride, puts minerals back. When the loss side wins repeatedly, a white spot can appear where minerals have been lost. At that stage, NIDCR says, decay can be stopped or reversed, because enamel can repair itself using minerals from saliva and fluoride from toothpaste or from fluoride applied by a dentist. The American Dental Association (ADA) explains the same process on its MouthHealthy site: fluoride taken into enamel combines with calcium and phosphate to form fluoroapatite, a mineral that is more resistant to acid than the original enamel mineral.

Regrowth would mean something much bigger: building new enamel, with its original organized crystal structure, where enamel has already been lost, and restoring real thickness to a worn or damaged tooth. That is what the laboratory gel studies are trying to do, and it is what no patient treatment does today. A useful test when you read any claim is to ask which of the two the evidence actually shows. A study that hardens a white spot has shown remineralization. A headline that turns that result into regrown enamel has gone further than the evidence.

There is a third category worth keeping separate: restoration. A dentist can cover and protect a tooth with bonding resin, a veneer, or a crown. Those treatments can look natural and protect what remains, but the material is not enamel and nothing has regrown. Keeping remineralization, laboratory regrowth, and restoration separate makes most product marketing much easier to judge.

What the Enamel Gel Research Actually Shows

The phrase enamel gel usually points back to a small number of well publicized studies. Each one is real research. Each one also has limits that headlines tend to drop, so they are worth taking one at a time.

The calcium phosphate cluster gel, 2019

The study behind many gel headlines was published in Science Advances in 2019 by Changyu Shao and colleagues at Zhejiang University and Xiamen University. The team made extremely small clusters of calcium phosphate, about 1.5 nanometres across, and stabilised them with a chemical called triethylamine so the clusters would not clump together. Mixed into a gel and applied to human tooth samples and to hydroxyapatite samples in the laboratory, the clusters formed a continuous mineral layer that guided new enamel crystals to grow in the same orientation as the natural crystals underneath, a process called epitaxial growth. Within about 48 hours, the new layer was roughly 2.5 to 2.7 micrometres thick, and its hardness and structure closely matched natural enamel.

Those numbers explain both the excitement and the limit. Natural enamel is measured in millimetres, so a clinically useful repair would need to be hundreds of times thicker than a layer of under 3 micrometres, and the research team itself noted the method would need to be scaled up and adapted to different kinds of cavities before it could be controlled and effective in patients. The work was done on samples outside a living mouth, without saliva flow, bacteria, chewing forces, or the safety testing a treatment for people requires. Later work in this area also flagged a practical problem: triethylamine, the stabiliser that made the clusters work, is a harsh chemical that later teams have tried to avoid. In 2019 the researchers hoped human trials might follow within a year or two. Years later, no treatment based on this gel is part of routine dental care. That gap between a hopeful timeline and a delivered treatment is normal in this field, and it is a reason to treat every future date you read with caution.

Protein guided crystal growth, 2018 and 2025

A second line of work tries to copy the scaffold that ameloblasts use. In 2018, Sherif Elsharkawy, Alvaro Mata, and colleagues, then at Queen Mary University of London, showed in Nature Communications that a designed protein material could trigger and guide the growth of apatite crystals at several scales, producing organized structures that look and behave like enamel. The authors suggested future uses such as acid resistant coatings to protect exposed dentine tubules, the tiny channels involved in sensitivity. Those uses were proposals in a materials paper, not tested treatments.

Related work has continued. A 2025 paper in Nature Communications described a supramolecular protein coating, about 10 micrometres thick, applied to acid etched enamel samples, which then supported new crystal growth over a 10 day mineralization process in the laboratory while keeping the natural prism pattern of the enamel underneath. Again, the setting was extracted teeth and controlled solutions, the layer was micrometres thin, and the result, while technically impressive, sits at the materials stage rather than the patient stage.

Keratin scaffolds, 2025

The newest widely reported study came from King’s College London in August 2025, published in Advanced Healthcare Materials by Sara Gamea, Sherif Elsharkawy, and colleagues. The team extracted keratin, the protein found in hair, skin, and wool, from wool, and applied it to tooth surfaces. On contact with the calcium and phosphate naturally present in saliva, the keratin formed an organized, crystal like scaffold that attracted more mineral and built up a protective enamel like coating. In the laboratory tests reported by the university, the coating protected the tooth surface and sealed exposed channels linked to sensitivity.

The university release said the approach might one day be delivered as a daily toothpaste or as a gel applied by a dentist, and the team suggested public availability within two to three years was possible. Read that as a research team describing its hopes at the announcement stage, not a launch date or a regulatory approval, and remember how easily the 2019 timeline passed without a product appearing. As of this article, no keratin enamel gel or toothpaste from this research can be bought by a patient or offered by a dentist.

What laboratory stage really means

Between a result like these and a treatment in your dentist’s surgery sit several steps, each of which can stop a promising idea: showing the material is safe in living tissue, showing it works in a real mouth over a meaningful period, passing regulatory review, and manufacturing it consistently. The gel studies above sit at the first step or before it. That does not make them hype. It makes them early: scientists can now grow enamel like mineral on tooth samples in several ways, in layers a few micrometres thick, and nobody has yet turned any of those methods into a proven way to rebuild a patient’s worn or decayed enamel.

Enamel is also only one part of regenerative dentistry. Separate teams are working on whether scientists can regrow whole human teeth, and on medicines linked to research into a third set of teeth. Those programs have their own evidence and their own timelines, and none of them changes what is available for enamel today.

What Is Available to Patients Today

Fluoride, the proven baseline

Fluoride toothpaste used twice a day remains the best supported everyday protection for enamel. The ADA describes fluoride as helping to prevent decay by making enamel stronger and more resistant to cavities, and NIDCR lists brushing with fluoride toothpaste, fluoridated water where available, and fluoride applied by a dentist among the ways fluoride prevents mineral loss and replaces lost minerals. NHS guidance gives the same routine: brush twice a day with fluoride toothpaste, spit after brushing rather than rinsing, clean between the teeth daily, and cut down on sugary food and drink. None of this regrows enamel. All of it protects the enamel you still have and supports remineralization where loss is early, which is why dentists keep returning to it while gel research continues.

Dentists also have stronger fluoride options for people at higher risk. The ADA evidence based guideline on nonrestorative treatment of carious lesions, published in the Journal of the American Dental Association in 2018, recommended specific options for specific lesion types, including 5 percent sodium fluoride varnish, 1.23 percent acidulated phosphate fluoride gel, and 5,000 parts per million fluoride toothpaste or gel, among others, to arrest or reverse lesions in defined situations. Note what that means for the word gel: a fluoride gel used in dentistry today is a remineralization treatment, chosen by a dentist after an examination. It is not an enamel regrowth gel, and the guideline does not describe any product that rebuilds lost enamel thickness. The same guideline also recommended against one popular calcium phosphate paste ingredient, 10 percent casein phosphopeptide amorphous calcium phosphate, for the lesion types reviewed, which is a useful reminder that mineral sounding ingredients are not automatically endorsed.

Hydroxyapatite and bioactive glass products

Patients often ask about hydroxyapatite toothpaste, since hydroxyapatite is the mineral enamel is made of. These pastes supply calcium phosphate mineral directly to the tooth surface, and a growing set of small clinical trials has reported caries prevention results in the same range as fluoride toothpaste for some groups. The fair summary is that the evidence is promising but much smaller, shorter, and less independent than the decades of evidence behind fluoride, and some of the most quoted favorable reviews in this area include authors with links to a hydroxyapatite manufacturer. Hydroxyapatite is therefore best discussed with your dentist as a possible addition or alternative for your situation, not adopted on the strength of a regrow enamel claim, which no toothpaste can support.

Bioactive glass tells a similar story with a longer track record. Researchers at Queen Mary University of London developed bioactive glass formulations that dissolve slowly in saliva, releasing calcium, phosphate, and fluoride for up to about 12 hours and forming fluorapatite on the tooth surface. Toothpastes based on that research are on sale in several countries, aimed at remineralization and at reducing sensitivity by blocking exposed dentine tubules. That is a real, available category of product, and it is still remineralization and surface protection, not regrowth of lost enamel.

Coverings and restorations

When enamel loss is advanced, the available answers are restorative: a filling for a cavity, bonding to rebuild an edge or cover an area, or a veneer or crown to cover and protect a heavily worn tooth. These treatments use manufactured materials, they require a dentist, and they do not pretend to be new enamel. For a tooth that hurts or has a hole, they are also the treatments that actually solve the problem today, which is why delaying them while waiting for a gel usually leads to a larger restoration later. Our companion guide explains how cavities are treated and what a dentist actually does in more detail.

Why a Gel Cannot Treat a Cavity

A cavity is not just missing mineral. Once decay has broken through the enamel surface, the hole contains softened, bacteria infected tooth structure. NIDCR is direct about the consequence: a cavity is permanent damage that a dentist has to repair with a filling, after removing the decayed tissue. A gel spread over that hole cannot remove infected tissue, cannot sterilize the lesion, and cannot seal the tooth in the way a filling does. It would leave the decay in place underneath, where it can continue toward the nerve.

Early lesions are different, and this is where future repair research is most plausibly aimed. A white spot with an intact surface has no infected hole to clean out, so adding mineral back into it is a coherent goal, and it is the same goal fluoride already serves today. That is also why regular checkups matter: mineral loss spotted at the white spot stage can often be managed with fluoride varnish and changes to brushing and diet, options that are no longer enough once a hole forms. If you are unsure which stage you are looking at, that uncertainty is itself a reason for an examination rather than a purchase.

How to Read Enamel Repair Claims on Products

A few checks sort most product claims quickly.

First, translate the verbs. Repair, rebuild, restore, and regenerate sound alike, but on packaging they usually mean remineralization support: helping minerals return to early weakened enamel, or depositing a mineral layer on the surface. Ask what was actually measured in the supporting study. Surface hardness returning in a laboratory test is not the same as enamel thickness returning in a patient’s mouth.

Second, check the study setting. Was the work done on extracted teeth or enamel blocks in a laboratory, in animals, or in people? Over days, or over a year or more? In people with early white spots, or in people with cavities and worn teeth? A result in extracted teeth over 48 hours, like the 2019 gel study, cannot support a claim about treating your cavity at home, however good the science is.

Third, check who is making the claim and what they are selling. A university press release describes research. A product page describes something for sale, and it may borrow the vocabulary of research it had no part in. If a product promises to rebuild enamel thickness, replace a filling, heal a cavity, or make a dentist unnecessary, treat the promise as a warning sign. Look for the ADA Seal of Acceptance on United States products, which the ADA describes as showing a product has been tested and shown to contain what it claims for its accepted use, and bring any product you are considering to your dental visit so the claim can be judged against your own teeth.

Finally, watch the timeline words. The 2019 cluster gel team hoped for human trials within one to two years, and the 2025 keratin team suggested two to three years to public availability. Neither statement is a schedule you can plan treatment around. If a tooth needs care now, it needs care on today’s evidence, not on a forecast.

How to Protect the Enamel You Have

Protection is unglamorous and, today, far more effective than any repair product.

Brush twice a day for about two minutes with fluoride toothpaste and a soft brush, using gentle pressure, and spit rather than rinsing so the fluoride stays on the teeth longer. Clean between your teeth once a day with floss or interdental brushes. Timing matters with mouthwash too: rinsing with mouthwash straight after brushing washes away the concentrated fluoride the toothpaste left behind, so whether mouthwash should come before or after brushing is worth getting right if you use one.

Cut acid exposure where you can. Frequent sugary and acidic drinks do more damage than the same amount taken once with a meal, because each exposure restarts the acid attack NIDCR describes. Rinsing with plain water after acidic food or drink helps, and waiting a short while before brushing after a strong acid exposure avoids scrubbing enamel while it is softened. Limiting snacking between meals gives saliva, your built in mineral supply, time to do its repair work.

Two quieter causes deserve a mention at your next visit rather than self diagnosis. Grinding and clenching can wear enamel down mechanically; morning jaw ache, headaches on waking, flattened or chipped tooth edges are reasons to raise it, and a dentist can examine the wear pattern and discuss options such as a guard. A persistently dry mouth also raises risk, because saliva both buffers acid and supplies minerals; dry mouth has many causes, including medicines, so mention it to your dentist and doctor rather than simply drinking more water and hoping.

When to See a Dentist

Book an appointment promptly, rather than trying a product first, if you notice any of the following: tooth pain or an ache that does not settle; sensitivity to hot, cold, or sweet foods that lingers after the stimulus is gone; a visible hole, pit, or dark spot on a tooth; a chipped, cracked, or broken tooth; swelling of the gum, face, or jaw; or a white, brown, or black stain that is new or changing. NIDCR notes that early decay usually has no symptoms, and that advancing decay can cause toothache, sensitivity, and, if the tooth becomes infected, an abscess with pain, facial swelling, and fever. Swelling with fever needs urgent care the same day.

Go to regular checkups even when nothing hurts. Early mineral loss is much easier to manage than a cavity, and it is usually only visible on professional examination. How often you should be seen depends on your own cavity risk and enamel wear, so agree the interval with your dentist rather than taking a fixed interval from an article.

Questions Worth Asking Your Dentist

• What stage is my enamel damage: early mineral loss, a white spot, erosion, wear, or a cavity?
• Can this area be managed with fluoride and monitoring, or does it need a filling, bonding, or another restoration now?
• Is fluoride varnish or a higher strength fluoride toothpaste or gel appropriate for me?
• Would a hydroxyapatite or bioactive glass product add anything to my routine, or would it duplicate what I already use?
• Are there signs of grinding, acid erosion, dry mouth, or gum recession that change my care plan?
• I saw a product or a headline about an enamel regrowth gel. How does it compare with what the evidence supports for my teeth?
• How often should I be checked, given my cavity risk and the amount of enamel wear I have?
• What changes should prompt me to come back sooner than my next planned visit?

Frequently Asked Questions

Does enamel grow back?

No. Once enamel has been lost, the body does not grow it back, because the ameloblast cells that built it are lost before the tooth erupts. Minerals can return to enamel that is weakened but still present, which is remineralization, but thickness that has worn or decayed away does not return on its own.

Can a gel regrow enamel on teeth?

Not for patients today. In laboratory studies, gels and coatings based on calcium phosphate clusters, designed proteins, and keratin have grown thin enamel like crystal layers, a few micrometres thick, on tooth samples. No such gel has become a routine treatment, and none can rebuild a cavity or a heavily worn tooth.

Does fluoride regrow enamel?

No. Fluoride supports remineralization: it helps minerals return to early weakened enamel and forms fluoroapatite, which resists acid better than the original mineral. The ADA and NIDCR both describe fluoride in those terms. It does not restore lost enamel thickness and it does not replace a filling once a cavity has formed.

Does toothpaste regrow teeth or enamel?

No toothpaste regrows a tooth or rebuilds a large area of lost enamel. Depending on its ingredients, a toothpaste can clean teeth, deliver fluoride or other minerals that support early remineralization, form a surface mineral layer, and reduce sensitivity for some people. Those are useful effects, and they are different from regrowth.

What is the difference between remineralization and regrowth?

Remineralization returns minerals to enamel that is still there, typically at the white spot stage, and it is available now through saliva, fluoride, and professional care. Regrowth would mean building new organized enamel where enamel has already been lost. So far, regrowth has only been shown in laboratories, in very thin layers.

Can a cavity heal with a gel or a special toothpaste?

No. Once the enamel surface has broken down and a hole has formed, the decayed tissue has to be removed and the tooth restored by a dentist. NIDCR describes a cavity as permanent damage that a dentist repairs with a filling. Gels and toothpastes can help protect other teeth and can support early lesions that have not cavitated, but they do not heal a cavity.

When might an enamel repair gel become available?

No reliable date exists. A treatment would need safety testing, trials in people showing it works in a real mouth, regulatory review, and consistent manufacturing. Research teams have suggested timelines of a few years before, including for the 2019 cluster gel and the 2025 keratin work, and those suggestions should be read as hopes rather than schedules. Until a gel clears those steps, fluoride care, early detection, and regular dental visits remain the proven path.

What should I do if my enamel looks thin or my teeth feel sensitive?

See a dentist for an assessment. Sensitivity and visible thinning have many possible causes, including erosion, grinding, gum recession, cracks, and decay, and the right next step depends on the cause. A product chosen without that assessment can waste money and, worse, delay treatment that would have been simpler earlier.

Sources & references

• National Institute of Dental and Craniofacial Research (NIDCR), Tooth Decay. https://www.nidcr.nih.gov/health-info/tooth-decay
• American Dental Association, MouthHealthy: Fluoride. https://www.mouthhealthy.org/all-topics-a-z/fluoride
• Slayton RL and others, Evidence-based clinical practice guideline on nonrestorative treatments for carious lesions: a report from the American Dental Association, Journal of the American Dental Association, 2018. PubMed record: https://pubmed.ncbi.nlm.nih.gov/30261951/
• NHS 111 Wales, Tooth decay. https://111.wales.nhs.uk/Toothdecay/
• Shao C and others, Repair of tooth enamel by a biomimetic mineralization frontier ensuring epitaxial growth, Science Advances, 2019. DOI: 10.1126/sciadv.aaw9569
• Zhejiang University, A novel way to repair tooth enamel (research announcement for the Shao study). https://www.zju.edu.cn/english/2019/0903/c19573a1616188/page.htm
• Elsharkawy S and others, Protein disorder-order interplay to guide the growth of hierarchical mineralized structures, Nature Communications, 2018. DOI: 10.1038/s41467-018-04319-0
• Biomimetic supramolecular protein matrix restores structure and properties of human dental enamel, Nature Communications, 2025. https://www.nature.com/articles/s41467-025-64982-y
• Gamea S and others, Biomimetic Mineralization of Keratin Scaffolds for Enamel Regeneration, Advanced Healthcare Materials, 2025. DOI: 10.1002/adhm.202502465
• Queen Mary University of London, Centre for Bioengineering: Remineralising Toothpaste (bioactive glass research and products). https://www.seresearch.qmul.ac.uk/bioengineering/impact/toothpaste/