Hydroxyapatite toothpaste: what the studies really show

Is hydroxyapatite harmful? No, in toothpaste it has been rated safe by the EU committee SCCS since 2023. What does hydroxyapatite toothpaste do? In adults with low caries risk, as much caries protection as fluoride, and its strongest effect is on sensitive teeth. The evidence is real, but shorter than the marketing suggests. Here is the honest audit.

Since 2023, more and more toothpastes have been appearing on drugstore shelves in Austria, Germany and Switzerland with the promise of nano-hydroxyapatite, or fluoride-free and remineralizing. The fronts are professionally designed and the claims sound scientific. Anyone who looks soberly at the studies finds an interesting result: the substance works, the mechanism is plausible, the evidence is real, but it is considerably shorter and more nuanced than the marketing would have you believe.

This article sorts the scientific literature for consumers in Austria, Germany and Switzerland. You will learn what hydroxyapatite actually is, why the nano scale makes the decisive difference, how the substance performs against fluoride in head-to-head comparisons, where the evidence is genuinely solid (sensitivity) and where it is still thin (children, active high-risk caries), and what the EU authorities decided about it in 2023. The sources are exclusively peer-reviewed reviews and reports from established dental institutions such as the Cochrane Library, the American Dental Association and the European Commission's SCCS.

One thing up front: the question is not hydroxyapatite versus fluoride in a contest for the better substance. Both have a place, both have strengths, both have gaps. The question is which substance fits which profile, and where the marketing reaches beyond the evidence. That is exactly what gets sorted out here.

Hydroxyapatite toothpaste, fluoride toothpaste and the Minvelle gum compared. Compiled by Minvelle, last checked on 4 September 2026. The entries in the two toothpaste columns apply to 10 percent rod-shaped nano-hydroxyapatite and 1,450 ppm fluoride respectively, each used twice daily. The third column describes the Minvelle gum: a food product as a supplement between brushings, not a toothpaste and not a toothpaste replacement. The statements on caries prevention refer to the toothpaste studies, not to the gum.

What the table does not show: the data on hydroxyapatite toothpaste have grown strongly over the last five years. Fluoride has a seventy-year head start in scientific validation, and that is real. The question is not whether hydroxyapatite works, but in which use cases the evidence is already sufficient today to recommend it as an equivalent choice, and where fluoride remains (for now) the more solid choice.

Is hydroxyapatite harmful? The direct answer

No, not in the form used in toothpaste and mouthwash. Since 14 March 2024 that is no longer an opinion but EU law. Commission Regulation (EU) 2024/858 added hydroxyapatite (nano) to Annex III of the Cosmetics Regulation, entry 372, and permits the substance up to 10 percent in toothpaste and up to 0.465 percent in mouthwash. Before that, the substance sat in a regulatory gray zone: permitted, but without a formal safety assessment of the nano-scale particles. If you only want the safety question settled, the detailed assessment including side effects is in the article Is nano-hydroxyapatite safe?.

The permission is tied to conditions, and exactly these conditions are the real answer to the question of harm. Only rod-shaped, uncoated particles are approved, of which at least 95.8 percent (by particle count) have an aspect ratio below 3, the remainder at most 4.9. Needle-shaped particles are therefore out. Also excluded is any application in which the substance can enter the body via the lungs, meaning sprays and loose powders. Anyone who reads online that nano-hydroxyapatite is a concern is almost always reading a statement about exactly these excluded forms, not about the paste in the tube.

Swallowing is the second part of the question. Here hydroxyapatite has a structural advantage: it is the same calcium phosphate that tooth enamel and bone are made of. There is no intake limit for it comparable to fluorosis. The SCCS assessment on which the regulation rests found no systemic toxicity, no genotoxicity and no reproductive toxicity for the intended oral use. No relevant side effects were reported in the published clinical studies. For children under six, therefore, the issue is not poison but whether a fluoride-free toothpaste delivers enough caries protection, and that is a question for the pediatric dentist.

The honest addition: what German-speaking review bodies actually criticize about hydroxyapatite is not safety but efficacy. Medizin Transparent (Cochrane Austria) and the Verbraucherzentrale (Germany's consumer advice centers) both conclude that the evidence for caries protection and pain relief is thinner than the advertising sounds, and that the long-term effects of nanoparticles in the mouth should be researched further. That is a different charge from harmful, and it is regularly confused with it in forums. Safe means: it does no harm. Effective means: it helps measurably. The first point is regulated in the EU, the second is the actual debate, and from here on this article goes through it study by study.

Toothpaste with hydroxyapatite: what to look for on the label

Whether you are standing in front of the shelf at dm, Rossmann, Müller or in a pharmacy: the front of the tube is sales space, the back is the information. Since 2023, drugstore shelves in Austria, Germany and Switzerland have carried noticeably more toothpastes with hydroxyapatite, and the range of what they disclose is wide. This article does not rate individual products, because the assortment changes monthly. Instead it gives you the four details by which you can tell in a minute whether a toothpaste with hydroxyapatite reflects the evidence or only carries the name.

Price is not a reliable indicator of effect, but it is a statistical one: very cheap hydroxyapatite toothpastes often work with lower concentrations and without stating the particle shape. Anyone who ticks off the four points above holds the comparison between drugstore, pharmacy and online brand in their own hands, without depending on a best-of list. How to read the individual criteria in detail is covered further down in the section Which brands deliver what they promise.

Toothpaste with xylitol and hydroxyapatite: what the combination can and cannot do

Many hydroxyapatite toothpastes on the shelf list xylitol as a second active ingredient on the back, and the question of whether this combination does more than hydroxyapatite alone is one of the most common around the category. The short answer: the two substances work in different places, and none of the nine studies on this page tested the combination itself.

Xylitol is a sugar alcohol that serves as a sweetener in oral care and is not fermented into acid by the cavity-causing bacteria in the mouth. Hydroxyapatite is the calcium phosphate that enamel is made of and delivers mineral directly to the tooth surface. So xylitol addresses the bacteria and acid side, hydroxyapatite the mineral side. That is why manufacturers put both in one tube: not because a study proves the added benefit, but because the two mechanisms do not get in each other's way.

What was measured for hydroxyapatite is in the studies this article discusses in detail further down. The 18-month RCT of 189 adults (Paszynska et al. 2023, PMID 37533523) compared a fluoride-free hydroxyapatite toothpaste with 1,450 ppm fluoride and found non-inferiority in caries increment. The meta-analysis by Pawinska et al. 2024 (PMID 39471896) pooled five clinical and eight in situ studies on caries prevention. The Limeback review 2023 (PMID 36648809) evaluated 44 clinical studies on dentin hypersensitivity. In all three papers the test substance was hydroxyapatite, the comparator fluoride or placebo. Whether the pastes tested also contained xylitol was not the research question, and a xylitol effect was nowhere reported separately.

What that does not show: that xylitol amplifies the effect of hydroxyapatite, that the combination remineralizes better than hydroxyapatite alone, or that a toothpaste with both substances would be superior to fluoride. A randomized trial testing hydroxyapatite plus xylitol against hydroxyapatite without xylitol does not exist among the studies cited here. If you read xylitol plus hydroxyapatite on the tube, you get two individually plausible substances, not a tested synergy.

In practice that means: the label check above applies unchanged. What remains decisive is the amount of hydroxyapatite in percent and the particle shape; the xylitol share is a plus, but no substitute for them. The xylitol evidence itself comes mostly from chewing gum studies, not toothpaste studies, and is worked through separately in the article Xylitol gum benefits for teeth: 20 years of research summarized. The same pairing, nano-hydroxyapatite and xylitol, is also in our gum for the time between brushings, with a published dose per piece, and with the same caveat: there is no study on the combination for that either.

What is hydroxyapatite, anyway?

Hydroxyapatite is a calcium phosphate mineral with the chemical formula Ca10(PO4)6(OH)2. In nature it occurs as the crystalline component of bone and teeth. In human tooth enamel, hydroxyapatite makes up around 97 percent of the composition by weight, with the rest being proteins, lipids and water. That makes hydroxyapatite the hardest mineral structure in the human body, with a Mohs hardness of around 5, comparable to apatite gemstones or glass.

The central idea behind hydroxyapatite toothpaste is mechanistically elegant: you apply exactly the mineral that enamel is made of onto the enamel from the outside. The substance is identical to the body's own, biocompatible, non-toxic, and it can integrate into the microscopic defects of the enamel. That is different from fluoride. Fluoride does not build itself into the enamel; it reacts with the hydroxyapatite crystals already present and converts them into fluorapatite. Fluorapatite is more acid-resistant than hydroxyapatite, which makes the enamel more resistant to acid attacks. Both routes are valid, but they work through different levers.

The history of hydroxyapatite in medicine does not begin in dentistry but in spaceflight. Bernard Rubin, a NASA researcher, investigated in the early 1970s how astronauts could preserve bone mass in weightlessness. In the course of that work he identified hydroxyapatite as the mineral lost from bone tissue during periods of weightlessness. Those studies led in 1974 to the patent on a synthetic hydroxyapatite formulation. Japanese researchers at Sangi Co., Ltd. licensed the substance in 1980 and brought it to the Japanese market in a toothpaste as its first application. In 1993 the Japanese health authority officially recognized nano-hydroxyapatite as an anti-caries agent, a decade before the substance registered in Europe.

In Austria, Germany and Switzerland, hydroxyapatite toothpaste has only been widely available since the 2010s, with a clear upswing since the SCCS safety confirmation in 2023. Before that the substance was in a regulatory gray zone in the EU: technically permitted, but without an official safety assessment for the nano-scale particles. That changed fundamentally with opinion SCCS/1648/22. Since then the dental research community in Europe has published noticeably more randomized trials on hydroxyapatite toothpaste, which explains today's increasingly solid evidence base.

The five core properties of hydroxyapatite for oral care

1. Identical to the body's own. Identical to around 97 percent of natural enamel. No foreign substance, no absorption problem.
2. Biocompatible. Used since the 1970s in orthopedic and dental surgery as a bone substitute material. No immunological reaction.
3. Mechanically hard. Mohs hardness 5, comparable to apatite gemstones or glass. Stable against mechanical abrasion.
4. Acid-sensitive. Dissolves into solution below pH 5.5. That is the Achilles heel of tooth enamel and at the same time the mechanism that explains the need for remineralization.
5. Nano-scale action. Only at particle sizes below 100 nanometers can the substance interact with the natural enamel microstructure. Coarse hydroxyapatite particles have practically no clinical effect.

How does nano-hydroxyapatite differ from conventional hydroxyapatite?

The central distinction between hydroxyapatite as a coarse powder and nano-hydroxyapatite is particle size. Coarse hydroxyapatite has particles in the micrometer to millimeter range. At that scale the substance cannot penetrate the microscopic defects of the enamel, because those defects are themselves only a few nanometers to a few micrometers in size. Coarse hydroxyapatite can adhere to enamel, produce a short-term smoothing effect and slightly raise salivary calcium, but it does not integrate into the crystal structure. Clinically, the effect is minimal.

Nano-hydroxyapatite (particles below 100 nanometers) is a different substance as far as the biophysical interaction with enamel is concerned. The natural enamel crystallites themselves have a characteristic size in the range of about 25 nanometers wide and 100 nanometers long. Nano-hydroxyapatite particles in the same size range can attach to the enamel surface, sink into the defects, and through their own crystal structure serve as a seed for further mineral growth. The substance thereby becomes an active component of the repaired enamel, not just a layer sitting on top.

Within the nano scale there are further differences that few consumers know about. Particle shape matters. Rod-shaped particles have a different surface chemistry from needle-shaped or spherical ones. The 2023 SCCS opinion explicitly classified only rod-shaped nano-hydroxyapatite particles as safe for oral care. Other shapes are not sufficiently studied and therefore fall outside the current approval. For consumers that means: credible brands state the particle shape, usually with the note rod-shaped.

Concentration is the second important variable. Clinical studies mostly work with concentrations between 5 and 10 percent by weight. Below 5 percent, the mineral-delivering effect is noticeably weaker in most published studies. The SCCS confirmed 10 percent as the upper safe limit, which happens to be the concentration used in most of the published efficacy studies. Brands that advertise nHAp without stating the concentration leave out the most important piece of information.

Another source of confusion is the origin of the substance. Nano-hydroxyapatite can be produced synthetically (the form used in most studies) or obtained from biological sources, such as fish bones, bone meal or eggshells. The synthetic form has controlled purity and particle size. Biological sources vary more and can contain residual traces of proteins or other organic matter. For clinical efficacy, however, what counts is the final particle characterization, not the origin.

How nano-hydroxyapatite compares with CPP-ACP and fluoride is broken down in our separate evidence ranking: nano-hydroxyapatite vs CPP-ACP vs fluoride. Whether particle size also matters in chewing gum is covered in the article Nano vs non-nano hydroxyapatite in gum.

Does hydroxyapatite toothpaste really replace fluoride?

This question sits at the center of every discussion about hydroxyapatite toothpaste. The honest answer is nuanced: in certain populations yes, in others no, and the evidence is differently solid depending on the use case. Anyone who gives a categorical version of either answer is ignoring the studies.

The mechanistic basis first: fluoride and hydroxyapatite solve the problem from different sides. Fluoride works by reacting with the hydroxyapatite already present in the enamel and partly converting it into fluorapatite. Fluorapatite only dissolves into solution at pH values below 4.5, instead of 5.5 like hydroxyapatite. The enamel thereby becomes more acid-resistant. So fluoride works indirectly, through chemical modification of the existing structure. Hydroxyapatite toothpaste works directly, by delivering the mineral itself that can be built into the enamel. Eroded enamel that is missing mineral can gain new substance with nHAp particles, instead of only making the remaining substance harder.

In randomized clinical trials of adults with low to moderate caries risk, the efficacy of 10 percent nano-hydroxyapatite toothpaste is statistically no worse than 1,450 ppm fluoride toothpaste. The central study is a double-blind 18-month RCT from the medical universities of Poznan and Bialystok, published in 2023 in Frontiers in Public Health (Paszynska et al., PMID 37533523, registration number NCT04756557). 189 adults were randomized to a fluoride-free hydroxyapatite toothpaste or to 1,450 ppm sodium fluoride, 171 of them analyzed per protocol. The primary endpoint was the share of participants without an increase in the DMFS index: 89.3 percent in the hydroxyapatite group versus 87.4 percent in the fluoride group. The pre-specified non-inferiority margin of 20 percent was clearly undercut. That is the methodologically cleanest caries study in the category to date. The disclosure belongs with it: three of the authors are employees of Dr. Kurt Wolff GmbH & Co. KG, the manufacturer behind Germany's best-known hydroxyapatite toothpaste line. The paper states this itself.

The 2022 review in Clinical Oral Investigations (Wierichs, Wolf, Campus and Carvalho, University of Bern, PMID 35103837) pooled five in vivo and five in situ studies on nano-hydroxyapatite, with at least 633 teeth in over 420 patients. Its finding is more precise than it is usually cited, and it is split in two: under remineralizing conditions, nano-hydroxyapatite and sodium fluoride showed the same potential. Under demineralizing conditions, by contrast, sodium fluoride was able to slow mineral loss, nano-hydroxyapatite was not, and there it did not differ from the fluoride-free control. For the in vivo studies no meta-analysis was possible because of the heterogeneity of the designs. The authors rate the certainty of the evidence as very low, identify a high risk of bias in six studies, and point out that six of the studies were funded or published by the manufacturers of the products tested. Their conclusion in the original: no final statement on efficacy can be derived from this. Those who sell hydroxyapatite like to cite this paper by half. It deserves to be cited in full.

Where fluoride remains clearly superior: in high-risk populations. Active multiple caries, dry mouth from medication or radiation, fixed orthodontic appliances or poor oral-hygiene compliance require the maximum protection that decades of fluoride research have documented. In these profiles hydroxyapatite is an add-on, not a replacement. In children under six, the evidence for nHAp toothpaste is very thin, and age-appropriate fluoride remains the first choice here. That matches the current position of the American Academy of Pediatric Dentistry.

The honest mid-risk answer

If you are an adult, healthy, with normal oral-hygiene compliance and low to moderate caries risk, you can, on the basis of today's evidence, choose hydroxyapatite toothpaste as an equivalent alternative to fluoride. That statement applies to 10 percent rod-shaped nHAp in a standard formulation, used twice daily. If you meet one of the high-risk conditions, you should regard hydroxyapatite only as a supplement to fluoride, not as a replacement. That is today's evidence-based answer, without marketing exaggeration in either direction.

What is the strongest over-the-counter cavity protection, fluoride or hydroxyapatite? On current data the answer reads like this: the most broadly documented over-the-counter cavity protection comes from fluoride, with decades of studies across all age groups. Hydroxyapatite showed non-inferiority to 1,450 ppm fluoride in the 18-month RCT of adults (PMID 37533523), meaning equivalence in the population tested. The Bern review (PMID 35103837) rates the overall evidence as very low and sees no superiority in either direction. The most effective choice for healthy adults at low risk is therefore: both are defensible, neither is superior to the other on the data. For high-risk profiles and children under six, fluoride remains the answer.

What studies exist on caries prevention?

The study pyramid for caries prevention with hydroxyapatite toothpaste has four levels: in vitro studies (test tube), in situ studies (intraoral appliances), clinical trials (real patients, randomized) and reviews. Each level delivers a different kind of information.

The in vitro data are the broadest. In test-tube experiments, enamel samples treated with nano-hydroxyapatite suspensions show a measurable reduction in acid softening compared with untreated controls. The effects are robust and well reproducible. This level proves the mechanism, but it says nothing yet about the effect in a real mouth, where saliva, plaque, diet and brushing behavior interfere.

In situ studies are the next level. Here participants wear removable appliances for a few weeks in which enamel samples are exposed to acid attacks and remineralization inside the oral cavity. These studies allow observation under realistic oral conditions without having to wait years for real caries to develop. Several in situ papers from the last ten years, for example in the Journal of Dentistry, show that nHAp toothpaste achieves the rehardening of artificially softened enamel at least at the level of fluoride. That is a robust intermediate step between test tube and real world.

Real randomized clinical trials with caries incidence as the endpoint are demanding. They need several hundred participants, run for at least 18 months (better three years) and cost millions of euros. The number of such trials for nHAp toothpaste is much smaller than for fluoride, but it is growing. The Polish study from 2023 (Paszynska et al.) is the most cited: 18 months, 189 adults, DMFS index, nHAp no worse than 1,450 ppm fluoride. There is also an older, smaller paper from the same group: in 2021 the team around Paszynska compared, in Scientific Reports (PMID 33514787), a microcrystalline hydroxyapatite toothpaste with a fluoride toothpaste over 336 days in 207 children with primary teeth and likewise found non-inferiority. Important for context: microcrystalline, not nano-scale hydroxyapatite was tested there, and the endpoint was ICDAS progression, not DMFS.

The review level is the summarizing layer. The 2022 Clinical Oral Investigations review already mentioned is the most cautious: equal potential only under remineralizing conditions, evidence very low, no final verdict. The most recent counter-position is in the Journal of Dentistry of December 2024: Pawinska, Paszynska, Amaechi, Meyer, Enax and Limeback evaluated 18 papers found and included five clinical and eight in situ studies in their meta-analysis (PMID 39471896). Their conclusion: the evidence for fluoride-free hydroxyapatite products in caries prevention has expanded. Here too the disclosure belongs with it, because two of the authors are employed by Dr. Kurt Wolff and all authors received travel grants from the same company. So today two systematic reviews stand opposite each other: an independent, very cautious one from Bern and an industry-affiliated, noticeably more optimistic one. A Cochrane review specifically on nHAp toothpaste does not exist so far.

What the evidence does NOT prove

Honesty requires naming the open questions too. Three points are not sufficiently answered by today's studies. First: long-term trends over five or ten years. The longest published caries RCT runs 18 months, which is short compared with the fluoride database that reaches across decades. Second: children under six. Here the picture is more nuanced than is often written. There is one randomized trial over 336 days in 207 children with primary teeth (Paszynska et al. 2021) that showed non-inferiority, but it tested microcrystalline, not nano-scale hydroxyapatite. That is not a broad data base like fluoride's. Third: the effect in high-risk populations with active multiple caries, where fluoride has a very robust database. Anyone who recommends a hydroxyapatite toothpaste for these profiles is placing a bet that is mechanistically plausible but not yet clinically proven. Why many dentists remain cautious given this evidence is written up in detail in Why don't dentists recommend hydroxyapatite?.

Sensitivity: where hydroxyapatite toothpaste clearly scores

If caries prevention is the still-growing discipline of hydroxyapatite research, the treatment of sensitive teeth (dentin hypersensitivity) is the discipline in which the evidence already stands clear today. In this area hydroxyapatite toothpaste can be recommended with sound justification.

Dentin hypersensitivity arises when the dentin tubules (microscopic channels in the dentin) lie open toward the oral cavity. That happens with exposed tooth necks, enamel erosion or after professional cleanings. Hot, cold, sweet or sour stimuli trigger a hydrodynamic pressure in the open tubules that is conducted to the nerve and produces the characteristic pain. The tubules have a diameter of around 1 to 3 micrometers, which is considerably larger than the nano-hydroxyapatite particles themselves, which typically measure 20 to 80 nanometers.

The mechanism of nHAp against sensitivity is physical: the nano particles settle into the open tubules and seal them. Unlike potassium nitrate, which dampens the nerve pain, or stannous fluoride, which forms a protective layer, hydroxyapatite toothpaste builds a mineral-identical plug into the tubule opening. This seal is not permanent; it is slowly washed out again by daily brushing and acid exposure, which explains the daily reapplication through brushing.

The largest summary on this is a systematic review with meta-analysis by Limeback, Enax and Meyer, published in January 2023 in Biomimetics (PMID 36648809). It evaluates 44 clinical studies in humans, more than half of them with a good GRADE rating. Versus placebo, hydroxyapatite reduced dentin hypersensitivity by 39.5 percent (95 percent confidence interval 48.93 to 30.06), versus fluoride by 23 percent (34.18 to 11.82). Versus other desensitizing agents the lead was 10.2 percent and was not statistically significant.

The conflict of interest belongs in the same breath: two of the three authors, Joachim Enax and Frederic Meyer, are employees of Dr. Kurt Wolff GmbH & Co. KG in Bielefeld, the company behind Germany's best-known hydroxyapatite brand. The paper discloses this. The numbers are therefore not worthless, but they were compiled by interested parties, and anyone citing them should say so. Most product pages do not.

Individual randomized trials support the picture independently of that. Vano and colleagues showed in 2014 in Quintessence International (PMID 25019114) and again in 2018 in Clinical Oral Investigations (PMID 28361171), in double-blind studies, a pain reduction from nHAp toothpaste. Butera and colleagues from the University of Pavia found in 2022, in 40 patients with white spots, a greater reduction in pain scores under biomimetic hydroxyapatite than under 1,450 ppm fluoride, while the erosion index BEWE did not change significantly in either group (PMID 35886524).

In practice that means: if you have sensitive teeth and are looking for a toothpaste that works not through nerve dampening but through physical tubule sealing, nano-hydroxyapatite toothpaste is an evidence-based good fit. The effect builds over the first two to four weeks, with a plateau effect after roughly six weeks. For very severe sensitivity, combining it with professional desensitization at the dentist's office can make sense.

And the gum? The one study that exists

The Limeback review contains exactly one paper in which hydroxyapatite was tested not as a toothpaste but as a chewing gum. Porciani, Chazine and Grandini randomized 107 participants to a sugar-free gum with calcium hydroxyapatite or a visually identical placebo gum, three times two pieces per day (Journal of Clinical Dentistry, PMID 25122980). After two weeks, the pain reduction in the test group was significantly greater than under placebo on all three clinical tests: 54 versus 30 percent on the tactile test, 66 versus 25 percent on the air blast, 49 versus 31 percent on cold water.

Three caveats belong with it, and we write them down even though we sell a gum ourselves. First, it is a single study over two weeks, and the review rates its certainty accordingly low. Second, the review dates it to 2016 in its Table 2, but it was published in 2014. Anyone who copies the year from a product page copies the error along with it. Third, the endpoint was pain sensitivity, not caries. A caries-incidence study on a hydroxyapatite gum does not exist to this day, not for ours either. What a hydroxyapatite gum can and cannot do on today's data is its own topic. If you want to know which brands publish a dose per piece at all, the comparison is in our database of hydroxyapatite gums.

Safety: what the SCCS decided in 2023

The safety assessment of nano-hydroxyapatite went through a formal scientific process of the EU Commission over several years. The Scientific Committee on Consumer Safety (SCCS) reviewed the dossier at the Commission's request and published the final opinion SCCS/1648/22 on 28 March 2023. That opinion is today the regulatory basis for nano-hydroxyapatite in EU oral care.

The core statements of the opinion are clear: nano-hydroxyapatite in rod-shaped particle form is safe for consumers when used in concentrations up to 10 percent in toothpaste and up to 0.465 percent in mouthwash. Other particle shapes (needle- or thread-shaped) were not sufficiently assessed and are therefore not covered. Spray or powder forms are likewise excluded, because possible aerosol inhalation and the associated lung exposure are not sufficiently studied. This differentiation matters: the safety assessment applies specifically to the paste and liquid form customary in cosmetics, not to every conceivable form of application.

The SCCS assessment rests on an extensive toxicity evaluation covering acute, subchronic and chronic toxicity, genotoxicity, reproductive toxicity and potential nanoparticle-specific risks. The central findings: nano-hydroxyapatite in the assessed form shows no systemic toxicity, no genotoxicity, no reproductive toxicity and no nanoparticle-specific risks in the intended oral use. That depth of assessment is substantial and puts nHAp on a similar regulatory safety footing to established cosmetic ingredients.

What the opinion does not address is the efficacy question. The SCCS is a safety body, not an efficacy body. The statement safe up to 10 percent in toothpaste says nothing about whether the product prevents cavities or reduces sensitivity. That efficacy has to be demonstrated through clinical studies, which is the job of the brands and the dental research community. Consumers should not confuse the two levels: SCCS clearance is a safety statement, not an efficacy statement.

One practical implication of the SCCS assessment: manufacturers bringing a hydroxyapatite toothpaste to market in the EU have to align particle shape, concentration and form of application with the SCCS requirements. Credible brands communicate this transparently (for example SCCS-compliant, rod-shaped 10 percent nano-hydroxyapatite). Anyone advertising nHAp without making conformity with the SCCS assessment visible should at least prompt the question of whether the specific formulation fits within the assessed framework.

Since March 2024 this assessment has been binding law. Commission Regulation (EU) 2024/858 wrote hydroxyapatite (nano) into Annex III of the Cosmetics Regulation as entry 372, with the same limits of 10 percent in toothpaste and 0.465 percent in mouthwash, the restriction to rod-shaped, uncoated particles and the exclusion of all inhalable forms of application. For consumers that is the practically most important point: a hydroxyapatite toothpaste sold in the EU has to comply with this framework, otherwise it is not marketable. The brand must also flag the nano status in the INCI list with the suffix (nano).

Which brands deliver what they promise?

In Austria, Germany and Switzerland there is now a growing number of hydroxyapatite toothpastes, from established Japanese brands through German pharmacy products to new DTC brands. Instead of rating individual products (which changes monthly), there are four concrete criteria that separate credible products from marketing-driven ones.

This article deliberately names no test winner in the classic sense. Anyone searching for a hydroxyapatite toothpaste test winner should measure every ranking against the same four points: without a quantity and a particle shape, a first place says little about the effect. The criteria below are the yardstick with which you can check any best-of list yourself. For chewing gums we have already applied the same yardstick and looked up the dose per piece for nine brands: How many mg of hydroxyapatite are in chewing gum?

1. A clear quantity in percent. Credible brands name the exact share of nano-hydroxyapatite, ideally 10 percent in line with the SCCS maximum. Anyone advertising only contains hydroxyapatite or with hydroxyapatite complex, without a quantity, gives the consumer too little information to judge the dose. That is an avoidable lack of transparency.
2. Stating the particle shape. The SCCS assessment covers only rod-shaped particles. Credible brands communicate this, often with the note rod-shaped or SCCS-compliant. Anyone who writes only nano-hydroxyapatite, without a shape, leaves out a relevant piece of information.
3. References to specific clinical studies. Brands that can rely on studies usually name them in product marketing or on the website. References should be specific (author, year, journal), not vague (clinically proven). Brands without any study reference operate purely on mechanism plausibility, which is too little for a substance with this evidence base.
4. A realistic claim. Credible brands say that nHAp can be an evidence-based fluoride alternative in adults, but stress the still-growing evidence and explicitly point children under six to fluoride. Brands that position nHAp as the natural choice against every kind of caries ignore the evidence in both directions.

Japan's Sangi Co., Ltd., as the historical pioneer, has the longest market experience with the substance. Several European pharmacy brands have followed since 2023, often with transparent communication of SCCS compliance. In the drugstore mainstream, some large brands are cautiously beginning to add nano-hydroxyapatite variants to their ranges; the depth of scientific communication varies widely here. As a general rule: the more expensive the product, the more likely you will find credible information on the back and on the website. Very cheap hydroxyapatite toothpastes often work with lower concentrations and poorly documented particle shape.

Three marketing claims that do not hold up

1. More effective than fluoride. The evidence shows non-inferiority, not superiority. This claim is overstated.
2. Repairs cavities. Nano-hydroxyapatite can remineralize early enamel erosion (white spots). A real cavity is an open enamel lesion that cannot be filled with toothpaste. The same applies to chewing gum, see Tooth repair gum: can it really rebuild enamel?.
3. 100 percent natural, because bio-identical. The form used in most products is synthetic nano-hydroxyapatite, produced in an industrial process. The substance is identical to the body's own, but the manufacturing is chemical, not botanical.

Practical verdict: who hydroxyapatite toothpaste makes sense for

The evidence allows a concrete assignment. Here are six typical profiles with the matching recommendation for each.

1. Adults with low caries risk who want to brush fluoride-free. Hydroxyapatite toothpaste with 10 percent nano-HAp is an evidence-based choice here. The 18-month study from 2023 and several further RCTs cover this profile with non-inferiority data. Recommendation: nHAp toothpaste twice daily, supplemented with xylitol gum after meals.

2. Adults with sensitive teeth. Here hydroxyapatite toothpaste has its most solid evidence. Several clinical studies show measurable pain reduction within two to four weeks. Recommendation: rod-shaped nHAp toothpaste twice daily, let the effect build over the first six weeks.

3. Parents of older children (six and up) who want to brush with reduced fluoride. For children over six who brush largely on their own and do not swallow toothpaste, nHAp toothpaste can be an option. For younger children, age-appropriate fluoride toothpaste remains the recommended first choice. Recommendation: agree the decision with the pediatric dentist.

4. Adults with active multiple caries or a high-risk profile. Here fluoride is the scientifically most robust choice. Several decades of data show a robust caries reduction in high-risk populations, which nHAp cannot yet demonstrate with that sharpness. Recommendation: fluoride toothpaste as first choice, nHAp products as a supplement where appropriate.

5. Adults with white spots or eroded enamel areas. Here hydroxyapatite has the mechanistic advantage: it delivers mineral directly that can be deposited into the eroded areas. Recommendation: nHAp toothpaste plus active acid avoidance (fewer snacks, more water) plus xylitol/nHAp gum after acid contact.

6. Pregnant and breastfeeding women. The SCCS safety assessment covers oral use at the intended concentration as safe, for the general population too. Anyone who prefers a reduced-fluoride routine during pregnancy can choose nHAp toothpaste as an alternative after consulting a dentist or gynecologist. With any change of routine during pregnancy or breastfeeding, individual medical coordination makes sense.

Three practical rules for use

1. Twice a day, two minutes, do not rinse. As with fluoride: after brushing, only gently spit out the foam, do not rinse thoroughly. The nHAp particles need contact time with the enamel surface to be able to deposit. Rinsing with mouthwash straight after brushing weakens the effect.
2. Be patient for at least four to six weeks. Sensitivity reduction builds over two to four weeks, enamel repair over six to twelve weeks. Anyone who notices nothing after a week has not used it long enough yet. Treat it as a routine measure, not an acute remedy.
3. Supplement the toothpaste with an acid routine. A toothpaste works while brushing. The acid attacks happen spread across the day. Water after every acidic drink, a xylitol-containing gum after meals, fewer snacking occasions: that noticeably amplifies the effect of any toothpaste.

Frequently asked questions