Does Fluoride Toothpaste Work?

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Hi, I’m Dr. B, practicing functional dentist for 35 years. I graduated from the Dugoni School of Dentistry in San Francisco, CA in 1987 and am a member of the American Academy of Dental Sleep Medicine (AADSM), Academy of General Dentistry (Chicago, IL), American Academy for Oral Systemic Health (AAOSH), and Dental Board of California. I'm on a mission to empower people everywhere with the same evidence-based, easy-to-understand dental health advice that my patients get. Learn more about Dr. B

Does fluoride toothpaste really work? You might be surprised to hear that the answer is…not really. While fluoride is proven to be effective in remineralizing teeth, it doesn’t have a strong enough concentration in toothpaste in order to be effective.

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Fluoride Toothpaste is Too Weak to Be Effective

Here’s what’s misleading: the concentration of fluoride in toothpaste is too weak to have an effect. That’s because they don’t add high concentrations of fluoride to regular toothpaste.

They add an amount that is safe in case it gets swallowed by a child, but not strong enough to really do the job of remineralizing your teeth topically.

The water system contains a fluoride concentration that is supposed to strengthen teeth from the inside when you drink water. It’s about .7 parts per million (ppm). (Check out my fluoride article from the first paragraph; the science behind this is actually pretty shaky and ingestion of fluoride over time like this might be doing more harm than good.)

You’re not swallowing toothpaste; you’re applying it directly to your teeth. This is called “topical” application, and you need a higher concentration of fluoride for this to work than you’ll find in over-the-counter toothpaste—around 5,000 parts per million.

Why doesn’t toothpaste just add the higher concentration of fluoride to make it effective? That higher concentration would severely damage developing teeth if swallowed, so the FDA doesn’t allow it.

This is why you can only get fluoride paste, which contains the right concentration for topical application, by prescription only.

Where does that leave us? If you bought your toothpaste without a prescription, then it’s likely too weak of a fluoride concentration to strengthen your teeth.

Fluoride Is Absorbed Best After You’ve Brushed

If you do get a fluoride toothpaste by prescription from your dentist, then you’ll be instructed to brush first before applying the paste.

The uptake of fluoride—in other words, how your teeth absorb the fluoride—isn’t optimal when your teeth haven’t been brushed yet. 

Teeth naturally grow a covering called biofilm, and this is the stuff you remove every time you brush. You have to remove the biofilm by brushing first, and afterwards, apply fluoride paste. This has to be a two-step process.

In other words, you can’t wash and wax your car at the same time!

Prescription Fluoride Toothpaste That Works

You can get a prescription fluoride gel from your dentist that will help with remineralization. I used to recommend (and use myself) Colgate PreviDent 5000 Booster Plus every night before I went to bed.

I chose this brand to treat the areas of my teeth that are sensitive to cold and acids due to gum recession, and only after I’ve brushed to remove the biofilm. At the time, it was the best at remineralizing teeth.

The Toothpaste I Use Instead of Fluoride

I say “used to recommend” above, because I almost never prescribe fluoride anymore (or use it myself).

See, there’s a better product on the market now for most consumers. I’ve been following the research for years and I’m confident that it’s the best option for myself and my family (and yours!) to remineralize cavities.

It’s called hydroxyapatite toothpaste. Hydroxyapatite (Ha) particles make up 90% of the structure of your teeth, so your teeth uptake it with ease.

Ha toothpaste is non-toxic, unlike fluoride toothpastes that require a Poison Control warning on the back. If your little one were to swallow an entire tube of it, the results would be about the same as if s/he drank a cup of bone broth!

The best part? Nano-hydroxyapatite works equally as well or better than fluoride in scientific studies!

Not a lot of these are available to buy yet. However, I now regularly use Boka’s Ela Mint Toothpaste, a nano-hydroxyapatite toothpaste that you can get as a subscription or as a one-time purchase.

Boka’s doesn’t foam much (because it has no SLS), which means it’s easier to hit that two-minute mark you need to disorganize your biofilm properly. It’s also free of other concerning ingredients in some toothpastes, like titanium dioxide, hydrogen peroxide, parabens, or synthetic flavors.

I also love RiseWell’s hydroxyapatite toothpaste, which comes in a fresh mint flavor and a birthday cake flavor, just for kids!

When I Still Prescribe Fluoride

There’s two notables exception to my new stance. I still write scripts for prescription-strength fluoride toothpastes to patients going through chemotherapy and radiation for cancer. I also prescribe it to those with extensive bulimia damage, for which prescription-strength fluoride can really help with tooth sensitivity.

I’ve found that, for these patients, fluoride does the most to decrease their painful sensitivity to hot and cold.

Final Thoughts on Fluoride Toothpaste

Let’s recap.

  1. Over-the-counter fluoride toothpastes don’t contain enough fluoride to actually remineralize your teeth. Plus, they’re toxic if swallowed.
  2. Prescription-strength fluoride toothpaste can definitely remineralize your teeth, but you’re running the risk of exposing yourself to a substance that’s toxic when ingested.
  3. A new development in dental technology, nano-hydroxyapatite toothpaste, works better than fluoride to remineralize teeth.

What other questions do you have about fluoride toothpastes? You can always send me a message by using the “Submit your question” link!

Mark Burhenne DDS

Learn More: The Complete Guide to DIY Toothpaste (And The Recipe I Use)


  1. Vano, M., Derchi, G., Barone, A., & Covani, U. (2014). Effectiveness of nano-hydroxyapatite toothpaste in reducing dentin hypersensitivity: a double-blind randomized controlled trial. Quintessence International, 45(8). Abstract:
  2. Tschoppe, P., Zandim, D. L., Martus, P., & Kielbassa, A. M. (2011). Enamel and dentine remineralization by nano-hydroxyapatite toothpastes. Journal of dentistry, 39(6), 430-437. Full text: