By the time we’re adults, most of us probably think we’ve got brushing our teeth figured out. We’ve been doing it everyday for most of our lives, after all. However, there is one part of the process that many people get wrong: they rinse their mouths after brushing!

After brushing your teeth, you should be spitting out the toothpaste, not rinsing then spitting. If the fact that you’re not supposed to rinse your mouth after brushing comes as a big shock, don’t feel bad. This is a very understandable misconception. From what we can tell, patients think of toothpaste like soap: something that aids in the removal of debris then gets washed away. But toothpaste isn’t like that for one very important cavity-preventing reason: fluoride.

Fluoride in an ingredient in toothpaste that prevents tooth decay by re-mineralizing and strengthening teeth. However, the less time the fluoride is on your teeth, the less time it has to prevent tooth decay. By rinsing with water you are limiting fluoride’s active time on your mouth to the amount of time you’ve been brushing. And given that most people don’t even brush for the full two minutes that the dentist recommends, that is not nearly enough time!

Upon hearing this prohibition of rinsing, one of the biggest questions we hear about is the dangers of swallowing toothpaste. While you should never swallow significant amounts of toothpaste, ingesting a tiny bit mixed with saliva after brushing your teeth is unlikely to do you harm (especially when compared to the risks of gum disease and tooth decay). But if you’re still very worried about it, you can rinse a little using this method: sip about a teaspoon (5 mL) of water and swish it in your mouth with the toothpaste to create a toothpaste slurry, then spit.

If the thought of having chemicals other than fluoride lingering in your mouth bothers you, you can try finding an all-natural fluoride toothpaste that has fewer ingredients. If it’s the lingering minty flavor that bothers you, there are toothpaste flavors other than mint out there, including bubblegum, watermelon and cinnamon. Just be sure they still have fluoride.

As an added bonus, not rinsing can also be better for the environment. Many of us unconsciously leave the water in the sink running as we brush our teeth, in anticipation of rinsing our mouths and the brush out at the end, wasting about 3 gallons (12 liters) of water each time. People who rinse their mouths are much more likely to waste water than those who don’t, so once you stop rinsing, you’ll probably stop wasting too!

A dry mouth is a uniquely uncomfortable feeling and should not be dismissed as a trivial issue for one very important reason: a dry mouth can make it more likely that you’ll get tooth decay! The presence of saliva in your mouth is an important part of keeping your teeth healthy.

Dry mouth, which is called xerostomia by dental professionals, is sometimes just a temporary feeling caused by regular activities such as strenuous exercise of speaking aloud for a long period of time. However, some people experience chronic dry mouth, which can lead to big problems over time: in other words, tooth decay.

The saliva in your mouth helps wash away cavity-causing bacteria as well as the food debris that such bacteria might feed on. In addition, saliva contains minerals that help strengthen teeth and can ever re-mineralize weak areas that might be at risk for tooth decay. All of these benefits of saliva are what makes its absence in the case of dry mouth so troublesome.

One of the most common causes of dry mouth is medication. Many medications (some say over 400!) can cause dry mouth, such as anti-depressants, diuretics, and antihistamines. Dry mouth can also be a side effect of radiation treatment in cancer patients because it can interfere with the salivary gland’s ability to create saliva.

Whatever the cause of dry mouth, it’s important to start treating it right away to reduce the risk of tooth decay. One easy solution is to sip water throughout the day to keep your mouth moist. You should also talk to the dentist about your symptoms and see if you may need to use a special mouthwash or artificial saliva product.

If your dry mouth could be a side effect of a medication, you can also talk to your primary care doctor about changing the medication to something that might not cause dry mouth. You should also avoid mouthwashes that contain alcohol, as these can make dry mouth worse. There are many alcohol-free mouthwashes that are just as tasty and effective.