Fluoride is a naturally occurring mineral that people add to water, food, and other products. Many toothpastes contain fluoride as it has benefits for protecting tooth health. Too much fluoride can pose risks to health, but the amounts contained in toothpaste are generally safe if a person uses the toothpaste as advised.

Toothpaste is an important part of good oral hygiene. With many options available, it can be difficult to know which one is the right choice.

Many toothpastes contain fluoride, a mineral that is naturally found in soil and rocks. This article examines what fluoride is and why manufacturers add it to toothpaste. It also covers the benefits and risks of fluoride and tips for choosing the best toothpaste.

Toothpaste ingredients

Producers have designed toothpaste to control dental plaque. Plaque is a thin layer that forms on teeth after eating sugars. The bacteria in plaque break down tooth enamel, cause decay, and lead to cavities.

People use toothpaste with a toothbrush to gently sweep away plaque and other debris from their teeth. All toothpastes share some common ingredients :

Abrasives such as calcium carbonate or calcium phosphate. These remove anything sticking to the surface of the teeth without scratching them.
Binders like sodium alginate or xanthan gum. These provide elasticity and form to the toothpaste, and help prevent it from drying out by binding water to it.
Humectants such as glycerol or propylene glycol. These retain water to prevent hardening of the toothpaste.
Foaming agents like sodium lauryl sulfate or sodium alkylsulfo succinate.
Preservatives, to prevent the growth of microorganisms.

Some toothpastes contain other ingredients, depending on their formulation:

fluoride, which strengthens enamel and prevents cavities
flavorings like spearmint, peppermint, or menthol
sweeteners, including sorbitol, glycerol, and xylitol
anti-sensitivity agents including strontium chloride or potassium nitrate

What is fluoride and why is it in toothpaste?

Fluoride is a naturally occurring mineral which exists in:

soil
rocks
water
many foods

It is an important part of tooth development in children under the age of 7, as it strengthens developing enamel. In children and adults it also slows down the acid-producing capability of plaque, which protects teeth from decay.

In many cities and countries, local authorities add fluoride to the drinking water, which has been shown to reduce tooth decay by at least 25%. Fluoride toothpaste provides an additional layer of protection against dental decay and plaque buildup.

Benefits of fluoride

Fluoride protects teeth against decay by helping strengthen developing enamel and slowing acid production of bacteria caused by plaque.

Fluoride protects teeth against a process called demineralization. This occurs when bacteria combine with sugars to create acid that erodes the tooth.

Further, fluoride promotes remineralization. This process brings calcium and phosphate ions to the tooth to create to new surface area which is acid resistant.

Risks

Too much fluoride can lead to dental fluorosis. Fluorosis is a condition that produces a change in the color of tooth enamel. This discoloration usually manifests as white or sometimes brown spots.

Fluorosis usually occurs when children who are in the teeth forming years swallow toothpaste rather than spitting it out. According to the Centers for Disease Control and Prevention (CDC)Trusted Source, the teeth forming years are before the age of 8.

Most cases of dental fluorosis are very mild to mild. In moderate to severe cases, more noticeable and extensive enamel changes happen, including dark spots and pits in the teeth.

The risk of getting too much fluoride from toothpaste is low and primarily a risk for children, who are more likely to swallow toothpaste.

To reduce the risk of dental fluorosis parents should:

supervise children age 6 and under to discourage swallowing toothpaste
use only a pea-size amount of toothpaste between the ages of 3 and 6
consult with a doctor or dentist about the use of fluoride toothpaste for children under 2 years of age. Typically a rice-sized amount of toothpaste is OK for children under 2.

Chronic exposure to high levels of fluoride can also lead to skeletal fluorosis. This occurs when fluoride builds up in bones, causing stiffness and pain. In the most severe cases, ligaments can calcify, causing pain and trouble moving. Typically this is a problem in areas with naturally occurring high levels of fluoride in drinking water.

Is fluoride safe?

While fluoride in toothpaste is generally considered safe, there is a larger, ongoing discussion of overall fluoride intake, from water, food, mouthwashes, and other sources.

The International Association of Oral Medicine and Toxicology (IAOMT), which advocates against the use of added fluoride in water and products, lists the following health problems which it associates with fluoride consumption:

acne
cardiovascular problems, including high blood pressure, cardiac insufficiency, and myocardial damage
diabetes
low fertility rates and early puberty in girls
osteoarthritis, temporomandibular joint disorder, and bone cancer
immune system complications
lower IQ
cognitive deficits, attention deficity hyperactivity disorder (ADHD), and neurological deficits
thyroid dysfunction

One 2016 study of children in Mexico found that higher levels of fluoride exposure before birth could result in lower cognitive abilities for babies when tested at ages 4 and 6–12. Researchers tested fluoride levels in 299 pregnant women, and in their children at ages 4 and 6-12. The results suggested a link between high levels of fluoride in the mothers and lower IQ scores in their children.

But other researchers who evaluated this study said the fluoride level used was double or triple the level found in drinking water in the United States. Researchers also failed to take into account other factors that could have contributed to lower IQ scores in the study.

Researchers evaluating other health concerns have also found problems with unreliable data and poor study design.

Overall, researchers have determined that studies linking major health conditions with fluoride are unreliable.

Fluoride has been used in drinking water for 75 years and research has proven its safety. As with many substances, too much can lead to problems such as fluorosis, but the right amount can provide important dental protection and minimal negative health effects.