How Bad Is It to Fall Asleep Before Brushing My Teeth?

It could be okay, it could be bad, but it sure as hell isn’t good.


Most of us have been guilty of not brushing our teeth at bedtime now and again. Maybe it’s because we forgot to pack a toothbrush when traveling, maybe we’re just too tired to deal with brushing before getting into bed, or maybe it’s because we’ve been partying so hard we completely forget proper dental hygiene procedures even exist. But we only skip it once in a while. What’s the harm?

Here is the harm. At the end of the day, there are millions of bacteria hanging out in your mouth, munching the same food you’ve been eating all day, secreting acid that eats away your tooth enamel. When you don’t brush before you go to bed, all the food particles that have accumulated in your mouth throughout the day hang out like an all-night buffet. The bacteria have the oral equivalent of an all-night rager, still secreting acid, but also sometimes merging with the food particles and mouth juices to form plaque, which also causes tooth decay, of course.

“You know it’s best for you to brush your teeth twice a day, but if you’re only going to do once, it’s better to do it right before you go to bed,” says Advanced Family Dentistry’s Vince Vargas. “Our saliva basically washes everything [in our mouths] constantly, cleaning everything every single day. But when you sleep, your saliva dries out until the morning, when you wake up.” Meaning that bacteria have been eating good and partying, uninterrupted, for hours, giving them ample time to wreck up the place.

There is good news. “Decay happens slowly, so it’s not like you’re going to get a cavity because you missed one day,” says Vargas. “So as long as you keep up brushing you’ll be okay.” However, some people will be okay-er than others. 

There’s no one single number of nights you can get away without brushing because everyone’s natural oral health is different. The only way you can hazard a guess is how your dental health has been so far. Can you make a dentist appointment every five years and remain cavity-free? Or do you brush twice a day, floss religiously, and see your dentist every six months and still find out you need a root canal? That’s the number of nights you can safely ignore your toothbrush. There’s no mathematical equation that can take your dental history and produce the number of skip nights you can safely have, but the worse teeth you have, the bigger gamble you’re taking when you don’t floss before bed.

It’s not fair, but it’s the tooth truth. Sometimes, it hurts.