Does Hydroxyapatite Toothpaste Whiten Teeth?

Plenty of hydroxyapatite toothpastes say “whitening” somewhere on the tube. Some say it in big letters.

So does it work? A little. And it works in a completely different way from the stuff your dentist uses.

Short answer: Hydroxyapatite can make teeth look slightly brighter by depositing a thin mineral layer that fills tiny surface defects and reflects light more evenly. Lab studies show a color change people can see, but the clinical evidence is modest and much of it comes from companies that sell the ingredient. It doesn’t bleach stains inside the tooth the way peroxide does. Where it does well is reducing the sensitivity that bleaching causes.

The two ways toothpaste normally whitens

First, a quick refresher, because “whitening” covers two very different things.

Most whitening toothpastes scrub. According to the American Dental Association, they primarily rely on abrasives to remove surface stains from coffee, tea or wine, and they won’t do much for the color of the tooth itself. The ADA considers a toothpaste’s abrasivity safe at or below 250 on the standard scale.

Bleaching is the other route. Peroxide diffuses into the tooth and breaks down colored molecules inside it, especially in the dentin underneath the enamel. That’s what changes the shade of a tooth rather than just cleaning its surface.

Hydroxyapatite does neither.

What hydroxyapatite does instead

Your enamel is mostly hydroxyapatite already, and up close it’s full of tiny scratches and pits. Brushing with hydroxyapatite deposits a layer of the same mineral onto the surface and into those gaps.

A smoother surface scatters light more evenly, which reads as brighter. A 2001 study that combined lab tests with volunteers found the whitening effect rose with hydroxyapatite content and wasn’t down to polishing. A 2022 lab study on 40 cow teeth found a 10% nano-hydroxyapatite paste changed color by 4.47 units after three applications, more than a 1% paste did, and researchers could see the crystals sitting on the enamel.

There’s one clinical result worth mentioning. A 2018 proof-of-concept study of hydroxyapatite combined with a peptide measured a color change of about 4.9 units after a week in people’s mouths, still 4.8 at 30 days. The authors describe it as an optical effect, and they worked for or had a financial interest in the company making the product.

How big is that, really?

Those numbers are on a color difference scale called delta E. For reference, a 2015 study on dental ceramics put the point where half of observers notice a difference at 1.2 units, and the point where they find it unacceptable as a mismatch at 2.7.

So a change of 4 to 5 units is visible. It isn’t a dramatic shift, and it’s a surface effect, so it needs daily brushing to keep up.

The catch: most of this happened in a lab

Honestly, the evidence is thinner than the marketing.

A 2023 systematic review found 17 studies on hydroxyapatite and tooth whitening, and 13 of them were done in the lab rather than in people. The authors described the clinical evidence as modest, coming from six preliminary trials, and two of the three authors work for a company that sells hydroxyapatite toothpaste. Another frequently cited 2020 study asked 46 patients whether their teeth looked whiter after four weeks. They said yes, but there was no comparison group.

We looked for a trial comparing hydroxyapatite toothpaste head to head with peroxide or a regular whitening toothpaste, measuring shade in real mouths. We didn’t find one.

Where it helps: sensitivity from bleaching

This is the use with the strongest clinical evidence, and it’s a little surprising.

Bleaching often leaves teeth sensitive. In a 2012 randomized trial of 42 people using a 7% peroxide whitener, those who brushed with a nano-hydroxyapatite paste had 36 days of sensitivity across the group, against 76 for the comparison group, and their teeth whitened just as much. A 2015 trial of 60 people found adding 2% nano-hydroxyapatite to a 6% peroxide gel cut sensitivity without weakening the whitening. And a 2022 trial found pretreating with nano-hydroxyapatite before in-office bleaching reduced sensitivity about as well as a fluoride gel did.

So if bleaching makes your teeth ache, hydroxyapatite is a reasonable thing to brush with before and during.

What we’d actually do

If your goal is a noticeably different shade, hydroxyapatite toothpaste won’t get you there on its own. Peroxide will, and the ADA’s guidance is the place to start, with a dentist if your teeth are sensitive or restored.

If you mostly want teeth that look smoother and a bit brighter, and you’re choosing a hydroxyapatite toothpaste anyway, the whitening is a small bonus that shows up in the research. Pick one for its other qualities, which we cover in our hydroxyapatite toothpaste picks. And skip charcoal, which has its own problems.

Frequently asked questions

Does hydroxyapatite toothpaste whiten teeth?

A little. It deposits a thin mineral layer that fills tiny surface defects, so teeth reflect light more evenly and look brighter. Lab studies show a visible color change, but clinical evidence is modest, and it doesn’t bleach stains inside the tooth.

Is hydroxyapatite better than peroxide for whitening?

No, they do different jobs. Peroxide changes the color inside the tooth, while hydroxyapatite works on the surface. We found no trial comparing the two head to head on shade. Hydroxyapatite does help reduce the sensitivity that peroxide bleaching causes.

How long does hydroxyapatite take to whiten teeth?

Lab studies saw a color change after a few applications, and one small clinical study measured it after a week. Because it’s a surface layer, the effect depends on continued brushing.

Can you use hydroxyapatite toothpaste while bleaching your teeth?

Yes, and there’s good reason to. Randomized trials found nano-hydroxyapatite reduced bleaching sensitivity without weakening the whitening result.

Is hydroxyapatite toothpaste abrasive?

Hydroxyapatite whitens through deposition rather than scrubbing, and a 2001 study found its whitening effect wasn’t due to polishing. Abrasivity still depends on the rest of the formula, and the ADA considers toothpastes at or below 250 on the standard abrasivity scale safe.

Related reading

The rest of this series: is nano-hydroxyapatite safe and natural toothpaste with fluoride. For vetted picks, see the best hydroxyapatite toothpastes. We’ve also compared hydroxyapatite against fluoride and looked at what charcoal does to enamel.

Sources: American Dental Association, Whitening and Toothpastes. Joiner, Journal of Dentistry, 2006. Niwa et al., Journal of Materials Science: Materials in Medicine, 2001. Shang et al., 2022. Bommer et al., 2018. Paravina et al., 2015. Limeback et al., 2023. Steinert et al., 2020. Browning et al., 2012. Vano et al., 2015. Gümüştaş et al., 2022.