There's a claim (Day9 / Centre for Clinical Interventions) out there that goes:

Don’t brush your teeth immediately after vomiting. While the teeth are covered in stomach acids, the vigorous action of the toothbrush may scratch the tooth enamel

However, I can only find official looking information when in context to pregnancy. Is the amount of damage done neglectable in non-pregnant adults?

Also, wikipedia lists gastric acid having a pH value of 1-3, while sciencebuddies.org (listing it at 1) mentions lemon acid is a 2 on the pH scale. If brushing your teeth with traces of acid in your mouth really is dangerous, shouldn't we hear about it without mentioning of vomit?

  • 2
    If it helps others to find an answer, I've heard that especially when womitting often, like some gallstone attacks, like every 10 minutes for hours until you fall asleep exhausted (been there, done that, no longer have a gallbladder), if you brush your teeth every time, your teeth will turn bad. But that is not womitting twice a year and brushing your teeth afterwards.
    – Bent
    Jul 8, 2016 at 13:26
  • You don't normally have a mouth full of undiluted lemon juice or vinegar. The "net pH" (probably not technically correct term) of vomit is probably lower (more acid) than most other things that spend time in your mouth.
    – IMSoP
    Jul 8, 2016 at 13:48
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    I don't marinate my teeth in vomit either
    – npst
    Jul 8, 2016 at 13:57
  • 5
    Regarding your last paragraph, I have heard it recommended not to brush your teeth too soon after drinking orange juice. I think it might have been making the rounds on the evening news a little while back. I might be able to find a reference for that. Jul 8, 2016 at 14:05
  • 2
    To @iamnotmaynard's point, this answer says that, quoting an authority.
    – Oddthinking
    Jul 8, 2016 at 14:19

1 Answer 1


If brushing your teeth with traces of acid in your mouth really is dangerous, shouldn't we hear about it without mentioning of vomit?

Yes, and we do (from Colgate):

You should know, however, that brushing your teeth after eating can sometimes affect your tooth enamel. According to the Mayo Clinic, if you've consumed anything acidic, you should avoid brushing your teeth for at least 30 minutes. Foods containing citric acid, like oranges, grapefruits and lemons, weaken tooth enamel. Brushing too soon after eating them can damage the enamel in its weakened state.

If you don't trust corporate sources, note the Mayo Clinic link that says the same thing. Avoid brushing teeth immediately after exposing them to acid. That source doesn't mention vomiting, but here's a link from a bulimia support group that does mention vomiting. It agrees with your original source. Do not brush your teeth immediately after vomiting. Rinse with water (can add baking soda) instead.

A more formal research overview says

It is concluded that keeping tooth unbrushed for at least 30 min after an erosive attack is necessary for protecting dentin (Attin et al., 2004).

Which it cites as from "Attin T, Siegel S, Buchalla W, Lennon AM, Hannig C, Becker K. Brushing abrasion of softened and remineralized dentin: an in situ study. Caries Res. 2004;38(1):62–66. doi: 10.1159/000073922. [PubMed] [Cross Ref]".

You may only be seeing this in pregnancy sources because of morning sickness. For most people, vomiting is rare enough that it's not going to be a big deal. Bulimics and pregnant women simply vomit more often and therefore get more advice. For most people, fruit (citric) juice is going to be more dangerous.

Note that they aren't telling people not to brush their teeth. Just to wait a while. Or to brush before the acid exposure, which is of course easier with citric acid than vomit.


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