Is fluoride bad for you?

Brian Maurer
June 30, 2021
Hygiene Tips and Recommendations
minute read

You may have heard something about fluoride in your dentist’s office a time or two. You may have also noticed that it shows up as an ingredient in many dental care products like toothpaste, mouthwashes, gels, and mouth rinses.

And, at some point, you may have heard about kids’ teeth being weak and stained because they were exposed to too much fluoride.

So why are they putting something in all these products if it can mess up your teeth? Is fluoride harmful? Or is it genuinely beneficial?

Let’s find out.

What is fluoride?

Let’s dig into the science for a second and talk about what fluoride is. Fluoride is a negative ion of fluorine and is notated by F- in chemistry class. But fluoride gets an A+ when it comes to dental health and cavity prevention, which we’ll explain more in a minute.

Fluoride is found in trace amounts in many natural elements, including water, soil, air, plants, rocks, and some foods. About 99% of the fluoride in your body is stored in your bones and teeth and serves to help mineralize them. This keeps your teeth and bones healthy and strong.

What does fluoride do to our teeth?

Fluoride plays a key role in the process of mineralization. What is mineralization, and how does it help your teeth?


Tooth enamel is the hardest substance in the human body, but it is not superhuman. When exposed to acid, it begins to lose minerals.

You might wonder how you’d expose your teeth to acid since you don’t make a habit of drinking it. However, many of your favorite foods and drinks are slightly acidic. These include coffee, lemons, oranges, wine, etc.

While overexposure to acidic foods can be problematic, the worst offender is the presence of bad bacteria in your mouth. These colonies produce acidic waste by breaking down sugars and carbohydrates, and this sits on your teeth, slowly leaching minerals from your enamel.

If the process is not stopped, enough minerals can leech away that your tooth enamel becomes damaged leading to cavities and other issues. Once lost, you cannot regrow new tooth enamel.


Before it gets to this point, however, you can remineralize your enamel. To do that, you need healthy, strong minerals, and fluoride fits the bill perfectly.

It also slows demineralization by raining on the harmful bacteria’s parade. The presence of fluoride not only reduces the level of bacterial enzyme activity but also may inhibit bacterial growth. Less acid in your mouth = less demineralization.

This process is what makes fluoride useful from an oral health standpoint. It helps prevent cavities, the second most common disease in the United States (behind the common cold).

Because of these benefits, communities began adding fluoride to public water supplies in the US in the 1940s. Currently, about 70-75% of the US population is receiving fluoridated water.

Is fluoride in toothpaste bad for you?

One potential drawback is that consuming too much fluoride over a long period may lead to fluorosis. 

There are two main types of fluorosis — dental and skeletal fluorosis.

Dental fluorosis

Dental fluorosis is less severe and affects the teeth. Most commonly, mild cases are seen and are characterized by white spots on the teeth.

Severe cases lead to unsightly brown stains and weaken the tooth enamel. This only happens in children when their teeth are forming, and the most critical period is under the age of two.

However, rest easy because your kids will have to ingest a lot of fluoride for these problems to occur. This generally only happens if they get way too much fluoride in their water or eat copious amounts of fluoridated toothpaste.

Brush their teeth with less than a pea-sized amount of toothpaste, and be sure they rinse and spit. It can be a good idea to use toothpaste without fluoride until they are able to spit and clean out their mouth consistently.

Skeletal fluorosis

Skeletal fluorosis is the most severe and also very rare. You have to be exposed to high fluoride levels for many years to develop this bone disease.

It happens when you start storing too much fluoride in your bones. At first, you might feel a bit of stiffness and joint pain, but eventually, symptoms can include calcified ligaments and altered bone structure.

Skeletal fluorosis mainly occurs in areas with a high fluoride concentration in the water, such as India and China. High levels of fluoride are defined at 8 parts per million (ppm). In US communities, the amount of fluoride in the water is generally around 0.7 ppm.

Assessments by expert groups

According to the American Dental Association (ADA), drinking water fluoridation in communities is perfectly safe. With over 75 years of research backing it and an approximately 25% reduction in dental caries (cavities) in both adults and children, the benefits are worth it.

The CDC also named water fluoridation one of the top ten great public health achievements of the 20th century.

How much fluoride is unhealthy?

When it comes to fluoride, there is definitely a sweet spot. Small amounts of fluoride are safe and highly beneficial; too much, and you may have problems.

Fluoride poisoning

An optimal dose of fluoride is between 0.05 and 0.07 mg F/kg of body weight. High doses of about 5 mg F/kg can cause fluoride poisoning.

Fluoride poisoning is rare but most often happens in children younger than 6.

Cancer risk

In recent decades a number of studies have looked into the possible link between water fluoridation and cancer risk. However, the concerns are generally unfounded. Fluoride exposure appears to have no effect on cancer risk.

Should you get fluoride products if you have a high risk of cavities?

With all this negative talk about the dangers of too much fluoride, you might be worried about using fluoridated products. However, don’t be too concerned about it. The benefits of using fluoride outweigh the risks, particularly if you have a high risk of cavities.

There is plenty of evidence that brushing with fluoride toothpaste daily is beneficial to your oral health.

Topical exposure to fluoride in toothpaste helps to remineralize the teeth and inhibits the growth of acid-producing bacteria, the true culprit behind tooth decay. Brushing helps dislodge plaque and tartar, which provide homes for the bad bacteria.

Curious how likely you are to develop cavities? There is a simple way to find out. We can analyze a small saliva sample to check the bacterial balance in your mouth. With minimal amounts of bad bacteria, you can enjoy good dental health and a low risk of cavities.

Send us a sample today to find out if you should be adding fluoride toothpaste to your daily dental hygiene routine!

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