Nano-hydroxyapatite is a synthetic, very finely milled form of hydroxyapatite, the calcium phosphate mineral that makes up most of your tooth enamel. It is the same mineral your teeth are already built from, produced in a laboratory at particle sizes small enough to interact with the enamel surface. It has been used in Japanese oral care since the 1980s, is now common in toothpaste sold in Australia, and is the ingredient printed on the front of every Perli pack.
The mineral your teeth are made of
Tooth enamel is the hardest substance in the human body, and it is almost entirely mineral. Around 97 per cent of it by weight is hydroxyapatite, a crystalline form of calcium phosphate. The dentine underneath is about 70 per cent hydroxyapatite, and so is a large share of your bone.
That matters because enamel does not repair itself the way skin does. It has no living cells. Once it is lost, the body cannot grow it back. What the mouth can do, all day, is trade mineral in and out of the enamel surface. Saliva carries calcium and phosphate, and the surface of a tooth is constantly gaining and losing them depending on what is going on around it.
What "nano" means here
Nano-hydroxyapatite is hydroxyapatite manufactured at nanometre scale, usually somewhere between 20 and 100 nanometres across. For comparison, a human hair is about 80,000 nanometres wide. Chemically it is the same compound as the mineral in your enamel. The point of making it small is that particles that size can sit in the microscopic roughness of an enamel surface rather than washing straight over the top of it.
It is synthetic in the sense that it is made rather than mined. It is not synthetic in the sense of being a foreign material. It is a manufactured copy of something the body already contains.
Where it came from
The idea is older than most people expect. Research into synthetic hydroxyapatite was pushed along in the 1970s by work on mineral loss in astronauts, who lose bone and tooth mineral in zero gravity. A Japanese company, Sangi, picked the material up and put it into toothpaste in the 1980s. In 1993 Japan's regulators approved it as an anti-caries ingredient, and it has been a mainstream oral care ingredient there ever since. Over the following decades it spread into toothpastes across Europe, Canada and more recently Australia.
What the research says
Most of the published research on nano-hydroxyapatite is on toothpaste, because that is where it has been used longest. The studies describe particles adhering to the enamel surface, settling into microscopic defects, and acting as a local reserve of calcium and phosphate that the enamel can draw on. Laboratory and clinical work has reported effects on the smoothness of the enamel surface, on early-stage lesions, and on sensitivity.
A number of clinical trials have compared nano-hydroxyapatite toothpaste directly against fluoride toothpaste for preventing tooth decay, and several have reported comparable results. That is a substantial body of work, and it is why the ingredient has moved from a Japanese speciality to a mainstream one. It is also worth being straight about its limits. Most of the evidence is in toothpaste rather than in gum, the study populations and durations vary, and none of it suggests that any product replaces brushing, flossing or seeing a dentist.
Is it safe?
Hydroxyapatite is biocompatible, which is to say the body recognises it as its own material. It has been used in medicine for decades as a coating on hip and dental implants for exactly that reason. In 2023 the European Union's Scientific Committee on Consumer Safety published an opinion concluding that the nano form was safe for use in toothpaste at concentrations up to 10 per cent. If swallowed, it is broken down and handled like any other dietary calcium and phosphate.
Nano-hydroxyapatite and fluoride
These are often set up as rivals, and they are not really doing the same job. Fluoride works by being incorporated into the enamel surface, where it forms a slightly different mineral, fluorapatite, that is more resistant to acid. Nano-hydroxyapatite works by supplying the enamel mineral itself. One hardens the existing surface; the other adds to it. Plenty of people use both, in different products at different times of day. We will go into the comparison properly in a separate piece.
Where you will find it in Australia
Nano-hydroxyapatite toothpaste is now stocked by several Australian brands and retailers. Perli puts the same mineral into chewing gum, for the hours between brushes, and names it in full on the front of the pack rather than folding it into a blend with a trademark on it. The full ingredient list is on each product page. If you want to know what the rest of a gum pack is made of, start with what gum base actually is.
Quick answers
Is nano-hydroxyapatite the same as fluoride?
No. Fluoride hardens the enamel surface by forming fluorapatite. Nano-hydroxyapatite is the enamel mineral itself, supplied in a form that can settle into the surface. They work differently and are often used alongside each other.
Is nano-hydroxyapatite natural?
It is a manufactured version of a natural mineral. The compound is identical to the hydroxyapatite in teeth and bone; the manufacturing is what controls the particle size.
Is it safe to swallow?
Yes. It is calcium phosphate, and the body processes it as dietary calcium and phosphate. The EU's consumer safety committee has assessed the nano form as safe in toothpaste at up to 10 per cent.
Why does Perli name it in full?
Because it is the reason the product exists, and because a label you can read is the point. Many products fold it into a blend with a trademarked name. We would rather you could see the ingredient itself.
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