Why You Should Stop Rinsing Your Mouth After Brushing

Why You Should Stop Rinsing Your Mouth After Brushing
Photo: bbernard, Shutterstock

The core pillars of dental hygiene are widespread and well-known. Brush twice a day, floss daily, avoid sugary foods and drinks and — don’t rinse your mouth out after brushing?

Honestly, we just heard that for the first time in our not insignificant time on this Earth — and we were shook. To not rinse the minty conflagration of bubbles that just took over your entire mouth, to instead leave the residue percolating on your teeth seems…somehow wrong.

But according to the Oral Health Foundation and National Health Service of the United Kingdom, it’s right. Your teeth aren’t destined to rot and fall out if you don’t, but there are reasons to consider kicking the rinsing habit.

Why we should “spit don’t rinse”

A 2016 poll conducted by the Oral Health Foundation, an independent, UK-based oral health charity, found that more than 62% of respondents rinse after brushing — but that this habit can make us more prone to tooth decay. The organisation’s CEO Dr. Nigel Carter called rinsing our mouth after brushing “very bad” as it “washes away the protective fluoride left behind by brushing.”

Carter noted the prime importance of fluoride, saying it not only strengthens tooth enamel, making it more resistant to tooth decay, but “also reduces the amount of acid that the bacteria on your teeth produce. By spitting toothpaste out then not rinsing with water, it ensures that the fluoride…will remain on the teeth and continue to be effective.”

The study also revealed that 14% of respondents rinse with mouthwash directly after brushing — a habit we should also kick to the curb, as most over-the-counter mouthwash has less fluoride than toothpaste. (Side note: The study also found that that the majority of people who rinse are more likely to leave the tap running during brushing, wasting an average 11 l of water every time, and 8,706 l per person, per year.) Yikes.

While there isn’t a large body of research on the topic, a 2012 paper published in the British Dental Journal found “some evidence that the rinsing method, especially the volume of water, may impact the preventive effect of fluoride toothpaste.” While acknowledging the evidence base is limited, the authors concluded, “Rinsing with water after brushing with fluoride toothpaste can reduce the benefit of fluoride toothpaste” — and they suggested we “avoid rinsing with water/excessive rinsing with water.”

The argument for rinsing

But what about rinsing not only to flush out excess toothpaste, but also to get rid of any lingering food in your mouth? (Also to avoid swallowing toothpaste, which can cause stomach pain, or in large enough quantities, possible intestinal blockage.) Dr. Michaela Tozzi told the Science Times there is validity to this stance, citing “bacteria in the toothpaste after brushing.” Also, you may simply prefer how it feels. (A notably absent voice on the topic is the American Dental Association, which has made no statement on rinsing.)

The bottom line

While rinsing after brushing certainly isn’t a guaranteed recipe for tooth decay, if you want to get the full benefit of your toothpaste, you may want to let it sit on your teeth longer. (Especially since it’s recommended we brush our teeth for two minutes each time which, uh, isn’t happening).

According to Pennsylvania-based Noll Family Dentistry, it comes down to personal preference, but your general dental health and proclivity to get cavities should be taken into consideration. “If your teeth chip, crack or break easily [or if you consume a lot of sugar] it’s strongly recommended that you do not rinse after you brush to allow the fluoride to do all that it can.”

If you aren’t ready to give up rinsing completely, you can ease yourself in by letting the fluoridated toothpaste set for a few minutes before rinsing, or, as the the British Dental Journal researchers recommend, avoiding excessive water.

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