How Bad Is Falling Asleep Without Brushing Your Teeth?

Here's what happens when you fall asleep without brushing your teeth and why it's much more harmful than you think.

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brush before bed

Falling Asleep Question: How bad is falling asleep without brushing your teeth? Answer: Most people are shocked to hear this, but going to bed without brushing your teeth is like going to bed with poop in your mouth.

poop emoji

How can that be? Every time you have a meal, the bacteria that naturally reside in your mouth feast on the food you eat. Just like every other living organism, these bacteria excrete waste after a meal. This waste is highly acidic and breaks down tooth enamel, causing root decay and cavities.

When you hit the sack without brushing, plaque starts to harden and calcify on your teeth. Once plaque has calcified, it’s impossible to remove with a toothbrush and floss and can only be removed by the hygienist during a teeth cleaning.

It gets worse. The gums see plaque buildup as an infection, so your immune system springs into action to attack that infection. By attacking the plaque buildup, your body starts to destroy the healthy tissues that hold your teeth in place, making the gums begin to pull away from the tooth.

gum inflammation

Inflammation is a good thing that lets your body protect itself, but it can cause damage when it’s present for the long term. When you have the flu, inflammation destroys foreign invaders to get you healthy again. But imagine having the flu for years. Chronic inflammation puts extreme wear and tear on the body and studies have linked chronic inflammation in the mouth to hearing loss, dementia, and heart disease.

Okay, but is all this going to happen in just one night? No, but if you make a habit of not brushing and flossing before bed, this will absolutely happen over time.

So if it comes down to washing your face, changing into your pajamas, or brushing and flossing, you know which one I recommend. Taking two minutes to brush and floss before bed will save you years of pain and even extend your life.

What to Do When You’re Too Exhausted to Brush Before Bed

  1. Keep a toothbrush in the drawer of your nightstand. You don’t need toothpaste; just do a quick, gentle dry brush while you’re lying in bed. I use a snap-on sanitizer to keep it clean and smelling fresh despite the lack of toothpaste.
  2. Keep a flossing stick in the drawer of your nightstand. You can also floss with one hand while you’re lying in bed. Just grab the stick and bite down on the floss.
  3. Run your tongue over your teeth. Feel that? That’s called plaque and it’s like dense, low-cost housing for bacteria. The longer you let plaque sit in your teeth, the more you let the bacteria to proliferate and take hold in your mouth. Run your tongue over your teeth to create the habit; after a while, you’ll start to crave the feeling of slippery, clean teeth before you pass out in bed.

Mark Burhenne DDS

Read Next: Can Rinsing With Mouthwash Replace Brushing?

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Leave a Comment

  1. What if we use mouthwash instead of tooth brushing

    • That’s a great question! Mouthwash isn’t an acceptable replacement for brushing and flossing since it can’t remove plaque. You would think from all the mouthwash TV ads that mouthwash has the ability to swirl around teeth and magically evaporate plaque and tartar, but this isn’t possible. Plaque needs to be scraped off. Imagine scale in your bathtub. Pouring chemicals on it and expecting the scale to wash away doesn’t work — you have to get in and scrub. That’s not to say that this is how hard you should brush and floss — be very gentle, enamel can easily be scraped away! But rinsing with mouthwash just doesn’t cut it. Plus, the alcohol in mouthwash can dry out the mouth, making bad breath worse and disrupting oral health:

      Thanks for asking!

      • What mouthwash do you think is best for oral health?

    • Anonymous says:

      Is it ok to reuse floss?

      • Anonymous says:

        In my opinion no I don’t believe it would be very healthy for any teeth from anyone no matter how clean to reuse floss. The answer would just be, you can think it but don’t do it.

  2. really very informative, also the answer in comments about mouth wash 🙂

  3. A great article, very informative.

  4. Do gums grow back in to support the teeth again over time or is the effect permanent?

  5. Dr. Tubagus says:

    Now i know, why my mom always asked me to brush my teeth before sleep.

  6. What studies show proof of more plaque buildup overnight with brushing vs. without burshing? If one brushes 2-3 times a day but not right before bed is there actual clinical evidence demonstrated by a double-blind non- randomized trial that substantiates such thoughts?

    • Clint, think of this: when you wake up in the morning, what’s the first thing you do? Likely, you swallow and lick your lips. That dry mouth you feel in the morning is a result of sleeping with your mouth open and the reduced saliva production that occurs while you sleep at night. Any time you have less saliva present, you have more plaque buildup.

  7. Wow, now that I know what happens when I don’t brush, I’ll always keep in mind that it is like having poop in your mouth. lol

    • Poop breath says:

      Yeah, because you have poop breath like me. TWINSIES!!!!!!

  8. admire tarasana says:

    this is reall a nice piece of advice. .thank u dr

  9. Can cavities lead to swollen eyes in the morning?

  10. I am only 15 and I get swollen eyes every day so can cavities be the reason for that?

  11. I read about the gums and how there are pockets between them and the teeth. When brushing, would it be a good idea to angle the toothbrush in order to “dig” into the pockets so that they get cleaned out? Or would that cause the gums to recede more?

  12. Anonymous says:

    So if I don’t brush my teeth in the morning or during the day, but I brush them before going to bed, is that good?

    • It’s better than nothing! But ideally, you’d add a morning brush to your routine. Biofilm develops rapidly and once a day is just not enough.

  13. The gums around your teeth, can they tighten up again, or grow back? Or will it stay loose permanently? Is there any way to get them back the way they were before?

  14. Anonymous says:

    Everything is very open with a clear description of the challenges. It was definitely informative. Your site is very helpful. Thanks for sharing!

  15. Hello doc.. What food should we eat i read that i should stay away from onion and garlic but try eating citrus fruits because it helps..
    i never knew that when ykur mouth is dry bacteria builds easily.. thankyou

  16. Anonymous says:

    I usually treat my teeth very well. But there have been three separate days where I fell asleep and didn’t brush. Do I have cavities? Help!

  17. Thank you sooo much for the last section on “what to do when you’re too exhausted to brush before bed”!

  18. Since reading theses questions and answers to my 10 yr old daughter, she quickly ran into the bathroom got a toothbrush an floss an started right away
    saying I use to taste poop before mom!

    • Lisa, that is so cool! Thanks for taking the time to share. So glad this article could be of help!

  19. Mark, I was told by a dentist that I had no cavities, my teeth were fine, but I have gum disease. Why is it that you can have good teeth but bad gums?. When you clean the bottom teeth, should you angle the toothbrush downwards or upwards ?. And, which way should you angle the brush near the top teeth?. I have Asperger’s Syndrome, and have difficulty brushing my teeth. Also, are Aquafresh toothpaste and Colgate Pro Gum Health Mouthwash good products to use?. I find Corsodyl mouthwash tastes awful.

  20. Okay, this isn’t really a comment but a question. I usually brush at night before sleeping but yesterday, I slept off without brushing. I woke up with a heavy mouth and when I checked it in d mirror, I saw that it was really swollen gum? What can I do about it?

  21. Ok. I get it, always brush your teeth. But what I want to know is, despite it not being the best option, if one is too tired to brush their teeth one night (like, literally about to pass out tired) is it better to at least rinse your mouth out with alcohol free mouthwash than nothing at all? Or does it not make a lick of difference?

  22. Hi I live in New Zealand and I react to all the various flavours like peppermint, colours and additives like sorbitol. I get a really awful headache so I don’t brush that often! I know its bad but it beats having a horrible headache!!!!! What can I do? Also I find the same with mouthwash and floss.
    Please advise on what I can do!

    • Charlotte Coakley says:

      Hi Nicole I know of a toothpaste that might suit you?

  23. Great post here, actually i really learnt a lot in this post. It was highly informative and i think i will make it a habit. Brushing twice a day ain’t a big deal at all. Thanks and thumbs up

  24. Anonymous says:

    How to make things better if I fell asleep without brushing my teeth at night for some time already? I usually brush longer in the morning if I didn’t brush my teeth at night. I’m afraid cavities will start to develop .

  25. It was a quite an informative article on the ‘effect’ side of things and thank you for your effort. Would it be possible to get some tips and solutions on what to do straight afterwards. Additionally tips such as how to make sure no long term effects occur and how to do this, and help stabilize ]the effects of what may have occurred in the mouth/ on teeth. T^hank you.

  26. An excellent article on a very important subject, especially as tooth decay is still a common problem, and as you point out periodontal disease can have widespread systemic effects.

    I also recommend interdental brushes to my patients, in my experience they also work well.

  27. I have gotten myself into the habit of brushing twice a day and flossing once. You’re right; once I got into that habit, I started craving the feeling of clean teeth.

    My only question is (since I can’t find a consensus answer): should we be brushing before meals or after? I heard 30 minutes after eating is good. What is your opinion?

  28. Hi Doc,

    Thanks for your article! The other day I had to be hospitalised for a night because of a high-fever viral infection. I had brushed my teeth the night before, had been offered sweets during the day and, unaware that I would stay in the hospital, I had no toothbrush or floss with me. I could feel my mouth burning from the bacterial build-up and bad smell during the night ( I am sure that the high body temperature was a factor that contributed to the bacterial manifestation) and the only thing I could do was to frequently chew gums that the nurse had offered me. To make a long story short, I went 36 hours with no brushing. Can this have left plaque in my mouth which cannot be now removed by brushing/flossing alone?

    Thanks beforehand!

    • It’s very possible. Plaque of course forms almost immediatey. But tartar or calculus takes longer. It is possible that you did form calculus in that time, but it can easily be removed. One you feel better go see you hygienist for a cleaning. It’s all reversible!

      Sorry you had a fever and for the hospitalization.


  29. Wanda Nelson says:

    What about using a miswah stick?
    What about oil pulling at night instead of brushing?

  30. Ok so, I am 37 and have not been to the dentist since I was 18 years old. I would floss, rinse, and brush everyday for years. I would even scrape the plaque away every six months, on my own (with dental tools). I then started to develop sensitivity, so I started using Sensodyne. Realizing that was only masking the pain, and not really restoring the enamel. I chose a different route…I started to only floss and rinse daily, and only brush twice a week. Amazing results! Sensitivity lessened drastically (I believe all the brushing was brushing away the enamel making my teeth weaker), my breath improved due to ,’the poop’, which is actually good bacteria, believe it or not, and I noticed anytime I began brushing too much again, the sensitivity would always come back. This is my TRUE story…take it or leave it
    I also found out that the celebrity Jessica Simpson, doesn’t brush her teeth very much either. There are also parts of other countries that do not and they’re just fine…although American tooth decay can also have more to do with fluoride. I use fluoride free toothpaste

  31. That’s a mistake I made. I also missed dental cleaning check ups and cleanings for a few years. Now I need more frequent cleanings, interdental brushes and the Waterpik to keep my gums healthy. They made a difference in probing depths. Brushes and floss can’t clean deep pockets. We don’t need to be middle aged to have 6mm pockets.

  32. Hi,
    So I’ve had a horrible habit of not brushing my teeth at night, and even some days of not during the day if I’m running late to work. I’ve unfortunately kept this up for about 9 years, and am very ashamed of it. I want to permanently change these habits; I’m 26, a singer, and already have some signs of gum line cavities and drooping gums. I’d really appreciate a response, even if it is a bit if reassurance that if I make a permanent decision, I can prevent more serious health effects like the ones you described. Thank you again for the article posted with such important information.

  33. i never brush my teeth all my teeth are very yellow and the enamel has worn out can i still get my teeth white and non smelly breath.

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