Should you rinse after brushing your teeth? Experts don't entirely agree

Brush your teeth, spit out the toothpaste, then reach for a glass of water. For many people, that final rinse is simply part of the routine. It's how they've brushed their teeth for years, without giving it much thought.

But is rinsing really necessary, or could this everyday habit be doing more harm than good? The answer might surprise you, especially if you've always assumed that washing your mouth out is simply the natural final step.

Why some experts say you should spit, not rinse

The NHS recommends brushing twice a day with fluoride toothpaste, spitting out the excess and avoiding rinsing with water immediately afterwards.

The reason is fluoride. This mineral helps strengthen tooth enamel and protect teeth against decay. After brushing, some fluoride remains in your mouth. Rinsing with water washes away part of that residue, reducing the amount left behind.

The Oral Health Foundation gives similar advice: spit out the excess toothpaste rather than washing it away. You don't need to swallow anything or deliberately keep a mouthful of toothpaste in your mouth. Simply spit and leave the remaining residue alone.

Why Dutch guidance takes a different view

In the Netherlands, Ivoren Kruis takes a more relaxed approach. Its guidance says there is no absolute yes-or-no answer: people can choose whether to rinse after brushing or simply spit.

The organisation points to research that did not find the expected additional benefit from avoiding rinsing. In the clinical experiment it cites, spitting without rinsing did not lead to fewer cavities or a difference in the amount of fluoride found in dental plaque.

Interestingly, Ivoren Kruis also refers to research suggesting that taking a small sip of water, mixing it with the remaining toothpaste and rinsing for one minute before spitting it out may lead to fewer cavities.

That doesn't mean a big glass of water is recommended. A small sip is very different from thoroughly washing your mouth out. And these findings shouldn't be taken as proof that rinsing is always better: the research behind the different approaches needs to be considered in context.

What both sides agree on

Despite the difference in advice, the fundamentals are the same. Brush your teeth twice a day for around two minutes, use fluoride toothpaste and spit out the excess when you're finished.

The key disagreement is whether leaving the remaining toothpaste in your mouth without rinsing offers enough additional protection to make it worth changing an established habit.

If you follow British guidance, the recommendation is straightforward: spit, don't rinse. If you follow Ivoren Kruis, you have more flexibility, including the option of a small sip of water.

There's another mistake to avoid with mouthwash

The timing of mouthwash matters, too. The NHS advises against using mouthwash immediately after brushing, even if it contains fluoride. It can wash away the more concentrated fluoride left by your toothpaste.

Instead, use mouthwash at another time of day, such as after lunch. A fluoride mouthwash can help protect against tooth decay, but it shouldn't replace brushing with fluoride toothpaste.

The bottom line? You don't need to panic if you've always rinsed after brushing. But if you want to follow the British recommendation, try spitting out the excess and leaving the residue behind. Whichever approach you choose, brushing thoroughly twice a day with fluoride toothpaste remains the habit that matters most.