The Unexpected Reason You Should Skip Rinsing After Brushing Your Teeth

Brushing your teeth twice daily is a habit instilled in most people from a young age. However, one part of the routine—rinsing with water immediately after brushing—might undo the benefits of the entire process.

Dentists have increasingly warned against rinsing the mouth with water or even mouthwash right after brushing. The reason? It washes away fluoride, the ingredient in toothpaste designed to protect against cavities and tooth decay.

Fluoride is a naturally occurring mineral that strengthens tooth enamel and makes it more resistant to acid attacks. It helps prevent cavities and can even reverse early signs of tooth decay. Since the 1940s, fluoride has been added to public water supplies in many countries to support oral health, and its benefits are widely recognized.

The U.S. Centers for Disease Control and Prevention lists water fluoridation as one of the top public health achievements of the 20th century. To get the most out of toothpaste fluoride, it needs time to sit on the teeth and do its job. Rinsing it off right after brushing cuts that process short.

Dr. Arash Ravanbakhsh, a Canadian dentist and owner of Inglewood Family Dental in Calgary, explained in an interview with the New York Post:

“Once you have finished brushing your teeth, you should spit out any residual toothpaste. By rinsing your mouth with water immediately after brushing, you wash away the fluoride, which is there to help prevent things like tooth decay.”

After brushing, skip the rinse and let the fluoride work its magic.

Spitting out the excess toothpaste without reaching for the faucet helps ensure that the fluoride stays on the teeth longer and provides maximum protection.

This advice isn't limited to water. Using mouthwash immediately after brushing can have a similar effect unless the mouthwash contains fluoride and is specifically recommended by a dentist.

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According to Scottish dentists Clement Seeballuck and Nicola Innes, both from the University of Dundee, skipping the rinse is especially important at night. In an article for The Conversation, they explained that saliva production decreases during sleep, which means the mouth has less natural defense against bacteria and acid.

“At night, you produce less saliva than during the day. Because of this, your teeth have less protection from saliva and are more vulnerable to acid attacks,” they wrote. “That’s why it’s important to remove food from your teeth before bed so plaque bacteria can’t feast overnight.”

The dentists also stressed that the fluoride in toothpaste needs as much time as possible to work, especially overnight.

“Once you’ve brushed, don’t rinse your mouth with water or mouthwash – you’re washing away the fluoride! This can be a difficult habit to break, but it can reduce tooth decay by up to 25 percent.”

That percentage isn’t insignificant. Making one small change—skipping the rinse—can lead to a noticeable drop in dental problems over time.

Understanding Fluoride's Role

Dr. David Perlmutter, a renowned neurologist and author, emphasizes the crucial role fluoride plays in dental health. His research indicates that fluoride strengthens tooth enamel, making it more resistant to decay. Rinsing immediately after brushing can wash away the concentrated fluoride, thus diminishing its protective effects.

He recommends waiting at least 30 minutes before rinsing or consuming anything after brushing. This simple step can significantly enhance the toothpaste's efficacy and promote better oral health over time.

Next time you brush, skip rinsing so the toothpaste can keep working.

For those used to rinsing, breaking the habit can initially feel strange. Many people associate rinsing with a clean mouth, and old habits can be tough to change. But with a bit of consistency, the adjustment becomes second nature.

Dentists often suggest brushing with a pea-sized amount of fluoride toothpaste, spitting out the excess foam, and leaving the remaining layer of toothpaste on the teeth without rinsing. After that, it’s best to avoid food or drink (except water) for at least 30 minutes, or ideally, leave it overnight.

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Making one minor tweak to your brushing routine can pay big dividends for your teeth, and it won’t cost you a cent or add any extra chores. After brushing, spit out the excess toothpaste and skip the rinse.

Leaving a thin fluoride film on your enamel gives it more time to strengthen and protect your smile. It’s a tiny change with a surprisingly powerful payoff: better cavity defense, stronger enamel, and a brighter, healthier mouth—all without buying new products or fussing over extra steps.

Dental researchers suggest that proper timing is essential for maximizing fluoride benefits. Dr. Chris Kresser, a functional medicine expert, points out that many patients overlook the importance of this detail. His advice includes utilizing a pea-sized amount of toothpaste and avoiding rinsing to allow fluoride to work effectively.

This approach not only strengthens teeth but also promotes overall oral health. Incorporating this habit can lead to fewer dental visits and lower long-term costs associated with cavities and other dental issues.

In summary, the practice of rinsing after brushing may seem harmless, but it can undermine the benefits of fluoride in toothpaste. Dental experts like Dr. Perlmutter and Dr. Kresser remind us that adopting simple changes in our oral hygiene routine can yield significant long-term health benefits. By delaying rinsing and allowing fluoride to act on our teeth, we can enhance our dental health and reduce the risk of decay.

Future dental care should focus on education around these practices, ensuring patients are informed about the most effective methods for maintaining their oral health.