Fluoride Toothpastes vs. Hydroxyapatite Toothpastes – What's the Real Difference? | The Toothpaste Trilogy, Part II
Toothpastes containing hydroxyapatite have gained significant attention in recent years on social media, in the natural cosmetics sector, and on pharmacy dental care shelves. They are marketed as an alternative to fluoride toothpastes, and manufacturers claim they can, for example, repair enamel damage, reduce tooth sensitivity, and whiten teeth.
But how do hydroxyapatite toothpastes actually differ from traditional fluoride toothpastes? Can fluoride be replaced with hydroxyapatite, and what does current research on the subject say?
What is hydroxyapatite?
Hydroxyapatite is the same mineral that makes up most of tooth enamel. Hydroxyapatite consists of calcium and phosphate. Enamel is the hardest material in the human body.
The hydroxyapatite used in toothpastes is synthetically produced. The idea is that the substance would bind to microscopic damage in the enamel and help repair it.
This is based on a real biological phenomenon. The surface of a tooth is not completely static; rather, the enamel is constantly undergoing demineralization and remineralization. During acid attacks, minerals are dissolved from the enamel, and saliva, in turn, returns them to the tooth’s surface.
Hydroxyapatite toothpastes are designed to support this natural remineralization process.
How does fluoride toothpaste work?
Fluoride toothpastes remain the gold standard in dental care. There is very strong scientific evidence spanning decades regarding the benefits of fluoride.
Fluoride helps teeth in two important ways:
- It reduces acid production by bacteria in the mouth
- It strengthens tooth enamel against acid attacks
When fluoride is present on the surface of a tooth, fluorapatite forms in the enamel. Its structure is similar to that of natural hydroxyapatite, but it is significantly more resistant to acidity.
This difference is extremely important.
Hydroxyapatite vs. Fluoroapatite – Which One Withstands Acid Attacks Better?
Throughout the day, teeth are constantly exposed to acid attacks. Every meal, snack, soft drink, or acidic beverage temporarily lowers the pH level in the mouth.
When the environment becomes acidic enough, tooth enamel begins to dissolve.
Natural hydroxyapatite begins to dissolve more readily in an acidic environment than fluorapatite, which is formed with the aid of fluoride. Fluorapatite can withstand a lower pH level. Hydroxyapatite begins to dissolve when the pH drops to 5.5, while fluoroapatite does not begin to dissolve until the pH reaches 4.5; this represents a tenfold difference, since the pH scale is logarithmic. Fluoroapatite thus provides more effective protection for teeth against acid attacks caused by eating and drinking, for example.
In practice, this means that while hydroxyapatite can help repair minor damage to the enamel, fluoride makes the enamel more resistant to acids than natural enamel is on its own.
For this reason, the effectiveness of fluoride toothpastes in preventing cavities remains clearly better established.
Can hydroxyapatite replace fluoride?
At this time, the scientific evidence does not support replacing fluoride with hydroxyapatite.
Studies on hydroxyapatite show promise, but there are still relatively few of them. Furthermore, some of the studies are small in scale or funded by manufacturers, which weakens the strength of the evidence.
However, hydroxyapatite isn't entirely "hocus-pocus." It's entirely possible that it has beneficial effects on tooth enamel and tooth sensitivity.
At present, however, dentists still recommend fluoride toothpaste as the first choice for preventing cavities.
What about toothpastes that contain both fluoride and hydroxyapatite?
There are also toothpastes on the market today that combine fluoride and hydroxyapatite.
In theory, this could be a beneficial combination: fluoride strengthens enamel against acid attacks, and hydroxyapatite may contribute to the remineralization of surface damage.
However, more research is needed to determine whether this combination offers significant additional benefits compared to regular fluoride toothpaste.
Is fluoride toothpaste safe?
Yes. Fluoride toothpaste is safe when used in normal amounts. Sometimes, in discussions, fluoride is confused with the element fluorine, which is a toxic gas. However, the sodium fluoride used in toothpaste is not the same as free fluorine.
It is practically impossible for an adult to get a fluoride overdose from toothpaste under normal use.
Excessive fluoride intake during childhood can cause fluorosis, which is characterized by discoloration of the enamel. Fluorosis does not affect teeth that have already erupted; rather, it develops in the enamel of teeth that are still forming. For this reason, children’s toothpastes contain age-appropriate levels of fluoride.
Which toothpaste should you choose?
Based on current research evidence, fluoride toothpaste remains the most effective and reliable option for preventing tooth decay. Hydroxyapatite is not a substitute for fluoride, although toothpastes containing both fluoride and hydroxyapatite show potential for further development.
In addition to brushing with fluoride toothpaste, it is important to remember to clean between the teeth, maintain a sufficiently spaced-out eating schedule, and use xylitol after meals. These practices continue to form the foundation of good oral hygiene.
