Understanding Fluorine Uses: How a Gas Becomes a Tooth-Strengthening Compound

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If you flip over a tube of toothpaste and read the ingredients list, you're likely going to see fluoride listed as an active ingredient. Fluoride is a mineral that you'll find in soil, rocks and natural sources of water, as the American Dental Association (ADA) notes. It forms when multiple chemical elements combine together, and fluorine is one of the key elements needed to create fluoride. Learning how fluorine uses relate to your teeth can help you better understand the composition of fluoride and its role in your oral health.

Understanding Elements and Molecules

To understand the difference between fluorine and fluoride, it helps to know the basics of chemistry. Everything in the universe is made of atoms, and elements are simply substances that are made up of a single type of atom and cannot be broken down, such as oxygen, iron or hydrogen, explains the U.S. Nuclear Regulatory Commission. Fluorine is also an element.

When two or more atoms combine together, they form a molecule. It's possible for elements to combine with themselves or with other elements to create a molecule; for example, O2 is a molecule formed by two oxygen atoms, while the H2O molecule (aka water) is formed by two hydrogen atoms and one oxygen atom.

What Is Fluorine?

As the Royal Society of Chemistry (RSC) points out, fluorine is the most reactive of all the elements. In its gaseous form, it's especially attracted to metals, and steel wool can burst into flames in the presence of fluorine. Its volatility means it bonds easily with other elements to form compounds. Apart from when scientists may isolate the gas to experiment with fluorine uses — which requires special storage containers — you don't have to worry about encountering fluorine gas when you're out and about in the world. Because it's so reactive in its elemental form, it's only found on Earth as part of a compound, such as fluoride, as the National Center for Biotechnology Information (NCBI) notes.

How Does Fluorine Turn Into Fluoride?

So, how do you get from highly reactive fluorine to good-for-your-teeth fluoride? It has to do with the attraction between positive and negative ions and the bonds they make. Fluorine, which is negatively charged, turns into fluoride when it bonds with a positive ion, such as sodium, reports the American Dental Association (ADA). Once bonded together, the ions' charges are neutralized.

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

How Does Fluorine Help Your Teeth?

The combination of fluorine with either sodium or tin helps your teeth once it's in your mouth. When you use a product containing fluoride, such as 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, explains the ADA. 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 damage and help prevent cavities.

Where Can You Find Fluoride?

As the 13th most common element in the Earth's crust, fluorine is often found in minerals, according to the RSC. You don't have to go digging for rocks to get access to fluoride, though. Many municipalities add fluoride to water supplies. The Centers for Disease Control and Prevention reports that nearly 75 percent of the U.S. population has access to fluoridated tap water.

You'll also find either sodium or stannous fluoride in many toothpastes that have the ADA seal of approval. If you are concerned that you aren't getting an adequate amount of fluoride from your toothpaste and tap water, you can always talk to your dentist about in-office fluoride treatments to see if they are a good option for you.

This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to be a substitute for professional advice, diagnosis or treatment. Always seek the advice of your dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.

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You can get the benefits of fluoride from different places. It can work from an external source and from the inside of your body. To work the best, you need to get it from both. At home, you and your family should brush with fluoride toothpaste at least twice a day for two minutes, especially after eating breakfast and before bedtime.