By Dr. Dave Chotiner, DMD
I get asked about fluoride more than anything else, and the question has changed shape over the last two years. It used to be "should I use a fluoride toothpaste." Now it's "my state just stopped fluoridating the water, should I be worried."
Those are different questions with different answers. I want to give you both honestly, including the parts that are inconvenient for a company that makes a fluoride-free product.
What fluoride actually does
Your enamel is built from hydroxyapatite, a calcium phosphate mineral. It dissolves when the pH around it drops below roughly 5.5, which happens every time oral bacteria ferment sugar. Saliva then rebuilds it. Decay happens when dissolving outpaces rebuilding over months and years. More on that mineral here.
When fluoride is present during that rebuilding, some of it gets incorporated into the crystal as fluorapatite. Fluorapatite is more acid resistant than hydroxyapatite. It holds on until roughly pH 4.5 instead of 5.5. That one point of difference is the entire mechanism, and it is real. Fluoride works.
Community water fluoridation started in Grand Rapids, Michigan in 1945. The CDC later named it one of the ten great public health achievements of the twentieth century. I am not going to pretend that record does not exist.
What changed
Two things, and they get conflated constantly.
The science on how it works changed. For decades the assumption was that swallowing fluoride built it into developing teeth from the inside. We now understand the protective effect is overwhelmingly topical. Fluoride works at the surface of the tooth, from contact, not from ingestion. The CDC itself revised its position on this years ago. That matters, because it means the case for fluoride in toothpaste is much stronger than the case for fluoride in your stomach.
The exposure question got louder. In 2024 the National Toxicology Program published a monograph concluding with moderate confidence that higher fluoride exposure is associated with lower IQ in children. The critical detail, which almost nobody reports accurately in either direction: the exposures studied were above 1.5 mg/L. The US recommended level for drinking water is 0.7 mg/L, less than half of that. The monograph explicitly said there was not enough data to draw conclusions at US levels.
So the honest reading is not "fluoride is proven safe at any dose" and it is not "fluoride lowers your child's IQ." It is that the margin between the recommended dose and the dose of concern is narrower than people assumed, and reasonable people are now arguing about whether that margin is wide enough.
The part I will not spin
Utah and Florida have ended statewide fluoridation, and more states are debating it. If you want my clinical read: removing fluoride from water without replacing the protection it provided will increase cavities, and it will hit low income children hardest.
Modeling published in 2026 projected large increases in childhood decay and hundreds of millions in added Medicaid costs from state level bans. I have no reason to doubt the direction of that finding. Water fluoridation is a blunt instrument, but it reaches kids whose parents cannot afford a dentist, and nothing else in the system does that.
That is an uncomfortable thing for me to say. RevitaBite is fluoride free. I still think it is true.
So should you use fluoride
Here is how I actually advise patients, which is more boring than either side of the internet argument.
If you are high risk, use fluoride. High risk means a history of multiple cavities, dry mouth, exposed root surfaces, orthodontics, a high sugar or high snack diet, or a GLP-1 medication that has cut your saliva. Fluoride is the most evidence backed tool available and this is not the place to experiment. Dry mouth in particular changes the math.
If you are low risk and you would rather not, that is a defensible choice now in a way it was not fifteen years ago. Nano hydroxyapatite has real trial data behind it. Japan approved it as an anticaries agent in 1993. Randomized trials since have found hydroxyapatite toothpaste performing comparably to 1450 ppm fluoride toothpaste on caries outcomes. It is not a fringe position anymore.
If your water is no longer fluoridated, do not just do nothing. This is the failure mode I worry about. Somebody hears the water is no longer treated, feels vaguely relieved, and changes nothing else. The protection was doing something. If you are removing it, replace it, with fluoride toothpaste, with hydroxyapatite, with better habits between meals, with all three. The detailed comparison is here.
What fluoride never did
Worth naming, because this is where I think the debate actually misleads people.
Fluoride does not neutralize acid. It does not rebuild lost tooth structure. It does not help when your mouth is dry, because it needs saliva to work with. And it does nothing at all during the many hours a day when you are not brushing.
People treat the fluoride question as if it settles their oral health. It settles one variable. The bigger variable for most adults is what happens in the long stretch between brushing, when acid is being produced and nothing is working against it. That is true whether or not there is fluoride in your water. The full routine matters more than any one ingredient.
Where RevitaBite fits
I built RevitaBite for that stretch, not as a replacement for brushing and not as a statement about fluoride.
It uses nano hydroxyapatite because that is the mineral enamel is already made of, and because it works without needing to be swallowed or to sit in the water supply. Chewing stimulates saliva, which raises pH and carries calcium and phosphate back to the tooth surface. Xylitol suppresses the bacteria producing the acid in the first place. The xylitol evidence is covered here.
If you use fluoride toothpaste twice a day and chew this in between, those two things do not fight. If you have decided against fluoride, this gives you something doing mineral work rather than nothing. Either way the goal is the same: fewer hours where acid is winning unopposed.
I would rather you be well protected with fluoride than poorly protected without it. That is the honest version.
FAQ
Is fluoride bad for you?
At the levels used in US drinking water, 0.7 mg/L, there is no established evidence of harm. The 2024 National Toxicology Program monograph that raised concerns about IQ studied exposures above 1.5 mg/L, more than double the US level, and stated there was insufficient data to draw conclusions at typical US levels. The debate is about how wide that safety margin is, not about proven harm at recommended doses.
My state stopped fluoridating the water. What should I do?
Do not simply change nothing. The protection was having an effect, particularly for children. Replace it deliberately: fluoride toothpaste, or a nano hydroxyapatite alternative, plus attention to snacking frequency and the hours between brushing. The worst outcome is removing a protective measure and not substituting anything for it.
Does fluoride work by being swallowed?
Largely no. The current understanding, which the CDC revised years ago, is that fluoride's protective effect is overwhelmingly topical. It works by contact with the tooth surface during remineralization, not by being ingested and built into developing teeth from within.
Is hydroxyapatite as good as fluoride?
For low risk individuals, randomized trials have found nano hydroxyapatite toothpaste performing comparably to 1450 ppm fluoride toothpaste on caries outcomes. Japan approved it as an anticaries agent in 1993. For high risk individuals, those with multiple past cavities, dry mouth, exposed roots, or orthodontics, fluoride remains the more established choice and is what I recommend.
Why is fluorapatite more resistant than hydroxyapatite?
Hydroxyapatite begins dissolving at roughly pH 5.5. When fluoride is incorporated during remineralization, the resulting fluorapatite holds until roughly pH 4.5. That one point of pH difference is the whole protective mechanism.
Can I use fluoride toothpaste and hydroxyapatite together?
Yes. They are not in conflict. A common approach is fluoride toothpaste at brushing and a hydroxyapatite product between meals, when brushing is not an option. The aim is reducing the number of hours in the day when acid is acting on enamel with nothing working against it.
This article is for general information and is not a substitute for professional dental advice. Decisions about fluoride for yourself or your children should be made with your dentist or physician, who can assess your individual cavity risk.