Is Hydroxyapatite Safe for Babies? A Dentist Explains

By Dr Jack Brazel BChD · Reviewed by Dr John Krezel, Specialist Prosthodontist

Hydroxyapatite is appearing in more oral care products, from adult toothpastes to baby teething gels. If you are seeing it for the first time on an ingredient list and wondering whether it is safe for your baby, that is a fair question. New-sounding ingredients deserve scrutiny, especially when they are going into your child's mouth.

I am Jack, one of the practising UK dentists behind MamaSmiles. Here is a clear, evidence-based explanation of what hydroxyapatite is, why we use it, and what the safety profile looks like.

What is hydroxyapatite?

Hydroxyapatite is not a new or synthetic material. It is the naturally occurring mineral that makes up approximately 97% of tooth enamel, 70% of dentine, and 60% of bone. When you look at your baby's teeth, you are looking at hydroxyapatite.

The chemical formula is Ca10(PO4)6(OH)2. It is a form of calcium phosphate. In oral care products, it is typically used as a very fine powder (nano-hydroxyapatite or micro-hydroxyapatite) that can bond with the tooth surface and support the natural remineralisation process.

In simpler terms, it is putting the same mineral teeth are made from back onto the tooth surface.

How long has hydroxyapatite been used in oral care?

Hydroxyapatite has been used in Japanese oral care since the 1970s. NASA originally developed synthetic hydroxyapatite to help astronauts remineralise teeth and bones after missions in zero gravity. The Japanese company Sangi Corporation commercialised it for toothpaste in 1980, and it has been widely used in Japan ever since.

In Europe, hydroxyapatite toothpastes have grown significantly in popularity over the past decade. Brands across Germany, Switzerland, and the UK now use it as an active ingredient. In the dental profession, it is increasingly recognised as a credible approach to enamel support alongside fluoride.

Is hydroxyapatite safe for babies?

Yes. Hydroxyapatite has an excellent safety profile for infant use, and this is supported by several factors.

It is biocompatible. Because hydroxyapatite is the same mineral that teeth and bones are made from, the body recognises it as a natural substance. It is non-toxic and well-tolerated by soft tissue.

It is safe if swallowed. Babies cannot spit, so any oral care product they use will be partially or fully swallowed. Hydroxyapatite passes safely through the digestive system. This is one of the reasons it is preferred by many parents over fluoride for very young children, where the risk of excessive fluoride ingestion is a consideration.

No known adverse effects in oral care concentrations. Published research on hydroxyapatite toothpastes and gels has not identified adverse effects at the concentrations used in consumer oral care products. A 2019 systematic review in the Journal of Dentistry concluded that hydroxyapatite toothpaste is effective for remineralisation and showed no safety concerns.

Regulatory acceptance. Hydroxyapatite is approved as a cosmetic ingredient in the EU under EC Regulation 1223/2009. It is used in products across Europe and Japan without restriction for infant use.

How does hydroxyapatite help during teething?

Teething is typically discussed only in terms of discomfort. But from a dental perspective, it is also the moment your baby's enamel is first exposed to the oral environment. Newly erupted enamel is thinner and less mineralised than mature adult enamel, making it more vulnerable to acid attack and early decay.

Hydroxyapatite in a teething gel or baby toothpaste supports this emerging enamel in several ways:

It bonds with the enamel surface. Hydroxyapatite particles adhere to the tooth surface and fill microscopic gaps in the enamel structure, helping to strengthen it.

It supports remineralisation. Teeth constantly lose and regain minerals through the demineralisation-remineralisation cycle. Hydroxyapatite provides a bioavailable source of calcium and phosphate to support the remineralisation side of this process.

It creates a protective layer. Applied to the tooth surface, hydroxyapatite forms a thin coating that can help shield enamel from acid produced by oral bacteria.

In our MamaSmiles Teething Gel, hydroxyapatite works alongside xylitol (which reduces harmful bacteria), aloe vera, chamomile, and curcumin. The idea is that teething care should do more than just address comfort. It should protect the teeth from the moment they appear. For more on our ingredient choices, see our active ingredients page.

What is the difference between nano-hydroxyapatite and micro-hydroxyapatite?

You may see both terms on product labels. The difference is particle size.

Nano-hydroxyapatite (n-HAp) has particles smaller than 100 nanometres. The smaller size allows deeper penetration into enamel surface irregularities. Most of the clinical research on hydroxyapatite toothpaste has used the nano form.

Micro-hydroxyapatite (m-HAp) has larger particles. It still provides enamel support but may not penetrate as deeply into surface imperfections.

Both forms are considered safe for oral care use. The choice between them depends on the specific formulation and the product's intended use.

How does hydroxyapatite compare to fluoride?

This is one of the most common questions parents ask. Both hydroxyapatite and fluoride support enamel, but through different mechanisms.

Fluoride converts hydroxyapatite in the enamel into fluorapatite, which is more resistant to acid dissolution. It is highly effective and backed by decades of research. The concern for very young children is that excessive fluoride ingestion during tooth development can cause dental fluorosis (white spots or streaks on permanent teeth).

Hydroxyapatite works by directly depositing the same mineral teeth are already made from onto the enamel surface. There is no risk of fluorosis, and it is safe if swallowed in oral care quantities.

This is not an argument against fluoride, which remains an important tool in dental care. It is an explanation of why hydroxyapatite is a particularly sensible choice for babies and very young children who swallow everything applied to their mouths.

For a deeper look at how teething connects to long-term enamel health, see our complete dentist's guide to teething and enamel protection.

The bottom line

Hydroxyapatite is not an experimental ingredient. It is the mineral your baby's teeth are already made from, used in oral care since the 1970s, backed by a growing body of clinical research, and safe if swallowed. For babies whose teeth are just emerging and whose enamel is at its most vulnerable, it is one of the most logical ingredients a teething product can contain.