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by Elaine K Howley

February 5, 2021

Yellowing and browning can be a consequence of chemical exposure while swimming, but these tips can help

Making teeth whiter is big business—valued at more than $3.15 billion globally in 2016, according to a market analysis by Technavio Research. For swimmers, the interest in teeth whitening may be even more urgent because repeated exposure to pool chemicals can discolor the teeth.

Why Do Teeth Change Color?

There are many reasons why teeth change color. Teeth naturally yellow with age, and trauma to a tooth can cause it to turn a brownish color. Smoking is a sure-fire way to make your teeth go brown. Many foods and drinks, such as tea, coffee, red wine, soda, tomato sauce, and soy sauce can also darken your teeth by staining the outer enamel layer.

But chemical exposure can also dim the brightness of your smile—and for swimmers, this problem is sometimes referred to as swimmer’s calculus. This is the yellowing or browning of the teeth that many swimmers notice after regularly swimming at the pool for long periods of time.

Chemicals in the pool water that are designed to kill potentially infectious microbes, such as bacteria and viruses, elevate the pH level of the water above what’s typically found in saliva. This rise in pH kills the germs but also causes the salivary proteins to break down faster, leaving the teeth less protected and creating the right environment for organic matter to deposit onto the teeth, causing staining. Over time, this build up can eventually cause cavities or gingivitis, inflammation of the gums.

If the water you’re swimming in is either too alkaline or too acidic, that can create issues ranging from staining to enamel erosion. The latter is a loss of the protective outer layer of enamel on the tooth, which creates tiny cracks in the enamel, leading to nooks and crannies where staining particles can take up residence.

A 1983 study found that 15 percent of daily swimmers had enamel erosion, compared to 3 percent of infrequent or nonswimmers. This erosion can happen quickly. A study from 1986 found that just 27 days’ worth of exposure to acidic water led to noticeable dental erosion.

The Centers for Disease Control and Prevention recommends chlorine concentrations between 1.0 parts per million and 3.0 parts per million and that the pH level of pool water should be maintained between 7.3 and 7.7, about the same pH as the average human body. State and local public health agencies check on public pool operators to ensure that the water is being tested regularly and that the chemical balance is correct.

How Can I Reduce Tooth Staining?

Even if your pool is properly maintained, it’s entirely possible that your teeth have gone a bit brown after lots of regular lap swimming. Optimal pH levels of pool water are slightly alkaline. In such an environment, the calcium and minerals present in the mouth can still harden onto teeth rather than dissolve as they would if the environment were more acidic. This tendency, in conjunction with antimicrobial chemicals in the water, can cause proteins in the mouth to bind with minerals to form a hard, yellowish-brown mineral deposit—calculus—on the teeth.

But there are some things you can do to help reduce the effect:

Talk to the pool operator

Find out what type of chemicals they’re using and find out whether they’re adhering to pool maintenance best practices. If not, it might be time to find a new pool.

Look for a pool that uses a salt-water system

This approach to pool water sanitization still uses chlorine. The chlorine is freed up when salt molecules are split into its constituent parts, sodium and chloride. But the levels of free chlorine in the water tend to be a little less than in pools that use liquid chlorine to treat the water, and thus, may cause less teeth staining.

Brush your teeth before each swim

You take a cleansing shower before you get in, right? (You should, because trace amounts of organic matter on your skin, such as sweat, urine, and fecal matter, can disrupt the careful balance of pool chemicals and cause an excess generation of chloramines—gaseous byproducts of sanitizing chemicals neutralizing that organic material.) So why not clean your mouth, too? The cleaner you keep your mouth, the less plaque and other organic matter there is to stick to your teeth and cause staining. Brush before each workout to reduce the tooth-staining power of a long swim.

Rinse, but wait to brush after swimming

Although it’s wise to brush before you swim, you should wait to brush afterward. That’s because the enamel surface of the teeth may be softened if the water is acidic and be more easily damaged by brushing. Instead, immediately after swimming, rinse with plain water or a fluoride mouth rinse to help bring the pH level in your mouth back to neutral and help your mouth replenish its protective saliva layer. 

Visit your dentist regularly

Most healthy adults with no major dental problems are advised to visit the dentist for routine cleaning and checkups every six months. This is a key means of reducing the staining of the teeth that can result from swimming, according to a Spanish study of 404 participants conducted between July 1996 and March 1997. That investigation found that 60.2 percent of the frequent swimmers showed evidence of dental staining, even though the pools in the study were kept well within sanitization guidelines. Although the study noted that competitive swimmers are at high risk of dental staining, it also found that “professional dental cleanliness was a protective factor,” meaning those who kept up with their routine oral health needs saw less browning.

Monitor your mouth for changes

As with any other aspect of your health, it’s important to stick with a good oral hygiene program and make the time to visit your dentist, especially if you’re noticing any changes in your teeth or oral health. Dental health is a key component of overall health, and you don’t want your swimming habit to become a detriment to your winning smile.


  • Health and Nutrition


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