What Is Fluoride?

If you thought fluoride was a synthetic chemical additive to many oral care products, you are not alone. Actually, fluoride is a naturally occurring mineral that is found throughout the Earth's crust and widely distributed in nature. Some foods and water supplies contain fluoride as well. Fluoride is often added to community drinking water supplies that do not already have it at sufficient levels to help strengthen teeth and reduce tooth decay.

The effectiveness of fluoride in fighting cavities was discovered, in the 1930s, when researchers found that children who grew up drinking naturally fluoridated water had less tooth decay than people living in areas without fluoridated water. Studies since then have repeatedly shown that when fluoride is added to a community's water supply, tooth decay decreases.

The American Dental Association, the World Health Organization and the American Medical Association, among many other organizations, have endorsed the use of fluoride in water supplies because of its effect on tooth decay. It's even been referred to as "nature's cavity fighter," according to the American Dental Association (ADA).

How Does Fluoride Work?

The “how” behind the fluoride gets a little more technical – let’s dive in. Fluoride works during the demineralization and remineralization processes that naturally occur in your mouth. The demineralization process is started by the bacteria in the plaque on your teeth. The bacteria feeds on sugar and other carbohydrates in your mouth and produces acidic saliva that weakens tooth enamel. Fluoride helps control and protect against the damage caused by the demineralization process, keeping teeth resilient to its negative effects.

Other times, when your saliva is less acidic, fluoride helps by replenishing the calcium and phosphate ions that make your teeth harder and more protected. This process is called remineralization. Too much loss of minerals without enough replacement leads to tooth decay.

What Are the Benefits of Fluoride?

Fluoride helps teeth in two ways. When children eat or drink fluoride in small doses, it enters the bloodstream and becomes part of their developing permanent teeth. Additionally, fluoride becomes part of the saliva and helps strengthen teeth from the outside, so acids are less able to damage tooth enamel. This process keeps your teeth strong while also helping to prevent cavities and tooth sensitivity.

Origin of Fluoride: Fluorine

Now it’s time to get mineral. Fluorine is an element and, as the Royal Society of Chemistry (RSC) points out, it is highly reactive. Because it's so reactive in its elemental form, fluorine easily forms compounds. One of fluorine’s most well-known compounds is fluoride. This means that fluoride is a natural ingredient when used in fluoride toothpaste.

Some examples of fluoride compounds include calcium fluoride, sodium fluoride, sodium monofluorophosphate, and stannous fluoride (sometimes called tin fluoride). Sodium fluoride and stannous fluoride are two types that are often used in toothpaste.

How Does Fluoride Strengthen Teeth?

When you use a product containing fluoride, like toothpaste, the fluoride ends up in your saliva. When your teeth are coated in that saliva, the enamel (the outermost layer of the teeth) ends up absorbing the fluoride. Once there, the fluoride bonds with the calcium and phosphate that naturally exist in your enamel to create fluorapatite, which is a strong material that can resist decay and help prevent cavities.

Is Fluoride Safe?

Fluoride is safe and effective when used properly and in appropriate doses, but like anything else, it is possible to get too much of a good thing. After decades of research, the main risk linked to fluoride overuse is dental fluorosis, a condition that kids can develop if they're exposed to excessive fluoride for an extended period of time when they're too young.

Affected children may have teeth with white spots or lines, and in some cases, even brown or gray discoloration on the enamel of their teeth. Since all water fluoridation systems in developed countries are checked to maintain safe fluoride levels, fluorosis might occur when children swallow too much fluoride toothpaste. That’s why it's important to supervise them while they're brushing to ensure they're spitting along the way. It’s also best to keep fluoride tablets stored safely away from young children. You can discuss any concerns with your dental professional and they can recommend the best course of action for your child.

The Centers for Disease Control and Prevention (CDC) confirms that both the safety and benefits of fluoride are well documented. There has never been any scientific evidence linking fluoride to adverse health effects when consumed in the correct amounts. In fact, the evidence consistently shows that fluoride is safe and effective in the amounts your toothpaste and household tap provides.

It's not just the CDC that upholds the merits of fluoride, though; according to the American Dental Association (ADA), more than 125 organizations around the world also recognize its safety and value. These organizations include the ADA, the American Medical Association and the World Health Organization.

Fluoride Treatments and Supplements

Fluoride Treatments

You have a few options when it comes to fluoride treatments. Topical fluoride products are applied directly to the teeth, and they include toothpaste, mouth rinses and professional fluoride treatments in your dental office. Although they are only in the mouth for a short time, topical fluoride treatments cause fluoride levels in the mouth to remain higher for several hours after use.

As long as you have healthy teeth to begin with, the combination of fluoridated drinking water and fluoride toothpaste is likely sufficient for your daily routine. If your tap water isn't fluoridated, or if you drink bottled water that doesn't contain fluoride, your dentist may recommend in-office fluoride treatments to make sure you're getting the protection you need.

Professional fluoride treatments are applied as a gel, foam or varnish. The fluoride used for these treatments has a higher strength than prescription or over-the-counter mouthwashes or toothpastes and should only be applied by a professional.

Fluoride Supplements

If you are worried that your child isn’t getting enough fluoride, ask your pediatrician or dentist about a prescription for fluoride supplements. Fluoride supplements are best for children between 6 months and 16 years old who do not drink fluoridated water. They are available in liquid form for younger children and tablets for older children and teens.

A dentist or pediatrician can also prescribe fluoride rinses and gels if your child needs a higher level of fluoride than supplements can provide. Either way you go, always make sure to carefully supervise your children when they use any fluoride product and keep fluoride supplements out of reach from children.

Proper oral health starts with a good plan of attack. That means brushing at least twice a day and flossing daily to remove plaque that collects between each tooth, and don’t forget: schedule regular dental cleanings.

Oral Care Center articles are reviewed by an oral health medical professional. This information is for educational purposes only. This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your dentist, physician or other qualified healthcare provider. 


What's behind your smile?

Take our Oral Health assessment to get the most from your oral care routine


2.3 billion

people worldwide suffer from tooth decay


What's behind your smile?

Take our Oral Health assessment to get the most from your oral care routine


2.3 billion

people worldwide suffer from tooth decay