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I've heard that rinsing with water after teeth brushing lowers or negates the benefits that fluoride provides to our teeth, but I've also heard everything in between; from there's no problem with it, to rinse with as little water as possible, to mix water with toothpaste and rinse with it.

Example from http://www.theguardian.com/lifeandstyle/2011/feb/08/how-to-brush-your-teeth:

So, should you rinse your mouth out with water when you have finished brushing or leave some toothpaste in your mouth? "For children, I would say wash out, because if they still have adult teeth that have yet to come through, they may end up with too much fluoride in their body, which can damage their teeth. For adults, it's good to leave a film, but in moderation – you don't want a mouthful of toothpaste. I have a semi-rinse: I put a tiny bit of water in my mouth to brush away the toothpaste on my tongue."

and from http://lifehacker.com/5978107/dont-rinse-your-mouth-out-after-brushing-your-teeth:

I know this this is not common practice, but it is actually quite important! Fluoride, one of the active ingredients in toothpaste, doesn't spend much time in contact when your teeth when you are brushing. Thus, it is crucial to let it work after you have already brushed your teeth. According to dentist Dr. Phil Stemmer, from The Fresh Breath Centre in London, "Rinsing washes away the protective flouride coating left by the toothpaste, which would otherwise add hours of protection." If you are thirsty drink a glass of water before brushing your teeth!

In contrast, this article quotes http://www.oralanswers.com/rinse-after-brushing:

Previous studies have indicated that rinsing the mouth with a beaker of water after toothbrushing may compromise the caries reducing effect of fluoride toothpaste. It is concluded that post-brushing rinsing with water, under the conditions of this study, does not significantly affect the caries reducing effect of a fluoride toothpaste.

and

I think the reason that there is some disagreement on this subject is because not rinsing after brushing appears to be only beneficial if you are at a high risk of getting cavities.

And as two commenters said below, not rinsing feels kind of counter intuitive, but seems to be the way to go. Is it?

Assuming normal and healthy teeth, what's actually better? Which one carries the most benefits? Should we rinse with water or not? Are there studies about this? Is there a consensus yet?

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    You are just thinking about flouride? Think about all of the bacteria you have just scrubbed off your teeth. Do you want to digest all that stuff or do you want to rinse it and spit it out? – Kenshin Jun 27 '15 at 23:57
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    @NinjaDoc - You swallow approximately a liter of saliva a day. That liter contains approximately 100 billion microbes. Brushing your teeth is more to remove surface bacteria/plaque that produce the acids causing tooth decay. Rinsing and spitting to get rid of the toothpaste is a good idea, but it's not really related to digesting a bit of extra bacteria,. – JohnP Jun 28 '15 at 3:38
  • @NinjaDoc That's what I thought, but if you google around you'll find several sources suggesting that rinsing with water right after brushing is not a god idea. – Lyd Jun 28 '15 at 8:03
  • @JohnP Why is it a good idea to rinse and spit to get rid of the toothpaste, then? – Lyd Jun 28 '15 at 8:04
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    @JCPedroza - So you don't swallow the fluoride contained in the toothpaste. It's not a huge risk, but unnecessary. – JohnP Jun 28 '15 at 13:01
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The previous answer does not refer to clinical studies so I thought I would have a look.

TLDR; the clinical studies I've seen suggest not to rinse with water after brushing.


According to Doméjean, et al. (2018), you should not rinse after brushing.

For maximizing the topical effect of the fluoride toothpaste, patients should be encouraged to spit out excess toothpaste and not rinse with water after brushing (Doméjean, et al. 2018).

Ashley, et al. (1999) looked at the DMFT (Decayed, Missing or Filled Teeth) levels for rinsing with water and no rinsing, and the DMFT levels were lower amongst those who rinsed by other methods or did not rinse after brushing. However, those who claimed not to rinse had a lower mean DMFT than the other subjects, which was "on the borderline of significance".

The mean DMFT of the 1,137 subjects who rinsed with a cup or beaker of water after brushing was significantly higher (mean 3.97, SD 3.74) than those who rinsed by other methods or did not rinse (mean 3.61, SD 3.79, p= 0.012, table 1). This represents a 9% difference in DMFT when compared with those who did not use a beaker. The 69 (2%) who claimed not to rinse had a lower mean DMFT (2.91, SD 3.24) than the other subjects, which was on the borderline of significance (p= 0.063) (Ashley, et al. 1999)

So to answer your question

Should we rinse with water after brushing our teeth?

Looking at the DMFT levels after rinsing with water compared to not, and looking at Doméjean, et al. (2018), the clinical studies suggest not to rinse with water after brushing

References

Ashley, P. F., Attrill, D. C., Ellwood, R. P., Worthington, H. V., & Davies, R. M. (1999). Toothbrushing habits and caries experience. Caries research, 33(5), 401-402. doi: 10.1159/000016540

Doméjean, S., Muller-Bolla, M., & Featherstone, J. D. (2018). Caries preventive therapy. Clinical Dentistry Reviewed, 2(1), 14. doi: 10.1007/s41894-018-0025-5

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Rising removes the material the toothbrush detached. I see no reason NOT to rinse. The main use of tooth paste is actually to provide a suspension where the food and other particles can be incorporated during brushing. If you don't rinse, they will deposit again.

Source: https://www.choice.com.au/health-and-body/dentists-and-dental-care/dental-products/articles/toothpaste-whats-the-difference "Tartar is the build-up of hardened plaque that can lead to gum disease. Although regular brushing can minimise its build-up, tartar can only be properly removed by a dentist. Of the toothpastes we looked at, almost all contain a tartar suspension agent – the most common being pyrophosphates and xanthan gum – designed to suspend tartar particles in saliva and prevent them from clinging to teeth."

Other source: http://www.stab-iitb.org/newton-mirror/askasci/chem03/chem03188.htm

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    This post has the makings of a very good answer, but here on Health, we strongly encourage using references. They are the only way in which we can tell if information is reliable or not. If you are struggling to find good sources, check out, What are reliable sources? If you want to learn more about our site's stance on answers without references, check out, Should answers without references be immediately deleted? Thanks :) – michaelpri Sep 2 '15 at 17:01
  • The source I provided is no an academic one but the names of the compounds can be searched further by people interested in the details. – FarO Sep 3 '15 at 15:30
  • " I see no reason NOT to rinse. " -> From the OP question: "'ve heard that rinsing with water after teeth brushing lowers or negates the benefits that fluoride provides to our teeth" – Franck Dernoncourt Nov 9 '18 at 19:44

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