Two different ideas
Fluoride works as an added ion. It is the ingredient behind most of the cavity-prevention research of the last seventy years, and it is the standard the American Dental Association recommends.
Hydroxyapatite takes a different route. It is the calcium phosphate mineral that makes up most of tooth enamel, made in a lab and added to toothpaste as fine particles. It has been used in toothpaste in Japan since 1993, in Europe since 2006 and in Canada since 2015.
The children’s trial
Researchers in Poland followed children aged 3 to 7 for 336 days. Half used a toothpaste with 10% microcrystalline hydroxyapatite, the same formula as a children’s paste sold in Germany. Half used a children’s fluoride toothpaste with 500 ppm fluoride (as amine fluoride). Both groups brushed three times a day for three minutes: a parent brushed with an electric toothbrush in the morning and evening, and the children brushed themselves at noon with a manual brush.
The outcome was the share of children with a new early enamel lesion, or an existing one that got worse, on any of the back baby teeth checked. Among the 177 children analyzed as the protocol required, it was 72.7% with hydroxyapatite and 74.2% with fluoride. 202 children completed the final visit, and the intention-to-treat analysis of 207 children gave a similar result. The preset limit for “not worse” was 20 percentage points. The upper end of the difference was 9.5% in the paper’s results table (its summary gives 9.8%), well inside that limit.
The adult trial
A second trial followed adults aged 18 to 45 for 18 months. One group used a 10% hydroxyapatite toothpaste similar to that maker’s formula. The other used an otherwise similar toothpaste with 1,450 ppm fluoride (as sodium fluoride). Participants were instructed to brush at home twice a day for three minutes with an electric toothbrush.
The outcome was the share of people with no increase in decayed, missing or filled tooth surfaces: 89.3% with hydroxyapatite and 87.4% with fluoride, among the 171 analyzed as the protocol required (189 adults in the intention-to-treat analysis). The limit for “not worse” was again 20 percentage points, and the upper end of the difference was 6.84%. The authors note that this does not show hydroxyapatite is better.
What the trials leave open
The children’s trial used microcrystalline hydroxyapatite, not the nano form. The adult trial’s paper reports 10% hydroxyapatite but does not establish its particle size. Each compared one paste with one fluoride paste at one strength, with frequent brushing: three times a day for the children, two of those by a parent, and instructed twice-daily home brushing for the adults. “Not worse by more than 20 points” is the test the trials set, not proof that the pastes work the same. Both studies were funded by a hydroxyapatite toothpaste maker, and three authors of the adult trial worked for it. Neither study tested Tooth Wizard.
Those details matter when you read any brand’s marketing, including ours. A study of one paste tells you about that paste.
Is nano hydroxyapatite safe in toothpaste?
In June 2025 the European Commission’s Scientific Committee on Consumer Safety concluded (opinion SCCS/1677/25) that nano hydroxyapatite made of rod-shaped, uncoated particles of a stated size is safe in toothpaste at up to 29.5% and in mouthwash at up to 10%. It does not apply to needle-shaped particles. The opinion is about the ingredient, not any brand’s finished toothpaste.
How families decide
If you are choosing fluoride-free, you now have real trial data to read rather than slogans. If your child has a history of cavities, bring your toothpaste to the next dental visit and decide together. Tooth Wizard uses 10% nano-hydroxyapatite. It was not part of these trials.
