Facts about mouthwash

Originally published at: Facts about mouthwash | Boing Boing


Sounds like the sort of statistics created for an upcoming marketing campaign intending to increase sales of mouthwash.

Dental advice here in the UK is not to use mouthwash immediately after brushing the teeth as it will remove fluoride left by the toothpaste. Likewise, don’t rinse with water after brushing:

To avoid the inevitable British teeth jokes:

Though Tory health policies are working hard on behalf of Hollywood comedy writers and private dentistry alike.


An interesting subpopulation is the immunocompromised. A leading cause of death among us is sepsis, frequently from oral bacteria.


Just one data point, but I used to do mouthwash in the morning and fluoride rinse at night for many years. During covid, I saw the same or similar study and asked my own dentist what she thought. Her advice was to not use mouthwash at all, or only a fluoride non-alcohol one because the nondiscriminatory alcohol allegedly kills off more than just bad bacteria.

I tried several non-alcohol mouthwashes and had negative experiences, e.g. Listerine non-alcohol made the skin peel off my gums. Also went without for a while which left my mouth clearly feeling and tasting worse. So I compromised by upgrading my electric toothbrush and returned to fluoride alcohol-based rinse at night, and now my teeth and gums feel decent again. We’ll see how the next dental appt turns out.

No covid so far, tho.


In college, I got obsessed with the clean feeling of mouthwash.-so I started using it 4-5 times a day. Fast forward a couple weeks and my mouth was coated in white stuff and the campus Dr. confirmed I had thrush - which had taken over due to the lack of good bacteria in my mouth and I had to take a couple pills to knock it out.


Listerine was originally a floor cleaner. Nuff said


I’ve had that issue not only with mouthwash but also with several (most?) modern toothpastes. I’ve narrowed the problem down to a sensitivity to sodium laurel sulfate, which a disturbing number of these products contain. Looking online, it seems like this is a fairly common side effect, and it’s weird (well not really) that the manufacturers have ignored it.


I thought the same, but it’s not product universal for me. Been using Crest Pro-Health for years, which contains it, without issue. I guess YMMV case-by-case.


This is what my dentist recommended. I kind of miss the “burn” I got from alcohol-based mouthwash and find I don’t use it as often as I used to. :frowning:


I use Therabreath Healthy Gums Oral Rinse w/ Added CPC. It’s pricey per bottle, but you use very little at a time. It helped nix the beginning gingivitis I had and doesn’t seem to kill all bacteria, the way Listerine or alcohol based rinses do. Listerine seemed to increase my cavity count and make my breath worse once the too-strong taste wore off. At night I floss, tongue scrape, rinse with this, then brush with toothpaste that has Nano-hydroxyapatite. No rinse, so the nHA has a chance to do it’s remineralizing. Morning is just brushing with the same paste. Seems to work well. No new cavities, healthy gums, shiny teeth, and the sensitivity of some teeth is gone after roughly 6 months.


I 've always had the same concerns as others in the thread about using an indiscriminate and broad-based antibiotic everyday and so never used mouthwash. No breath problems and went decades without a cavity.

However, I was a nervous cheek-chewer as a youth, and have patches of keratinized skin that started to get frequently infected in the last 5 years or so. This year I started using mouthwash every night which has completely prevented further cheek infections but, of course, I had two cavities in my latest visit and my kids now complain about my breath.

One confounding factor: I didn’t go to the dentist for 2.5 years during COVID, and had always been a strict every-6-months guy before then. The last time I had a cavity was college, the previous time I neglected regular dental visits for years at a time…


The only mouthwash I use is Biotene for when my medication causes dry mouth.

My dentist and doctor both recommended it.

Doesn’t happen often but when I do get dry mouth it works well.

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I used Listerine “blue” flavor in my 20s and early 30s, then it started giving me dry mouth and occurrences of thrush. I gave it up and kept the rest of my oral care routine (brush 3 times a day; floss before brushing at bedtime) and have not have any cavities, excessive tartar/calculus buildup, or people commenting on malodorous emanations from my word hole, i.e. mouth.

My hygienist loves working on me because my teeth are so easy to clean, and I have yet to test positive for COVID-19 as well.


My dentist recommends avoiding alcohol-based mouthwash, not because it kills “good” bacteria but because it increases your risk of oral cancer.


Our dentists have recommended full-alcohol Listerine for a few years, as the best buildup remover. No mention of cancer or other issues experienced above.

But the OP reminds me of how little we are really prepared to take care of our bodies. Who taught us to brush our teeth? To wipe? What does our body do, and what does it need? What’s “normal” in any range of parameters? What matters most within those parameters? What’s an optimal way to care for ourselves?

It’d be great to have a better idea of “How Shit Works” in general and not just learn from someone who was embarrassed to learn it from their own parents.


FWIW, from @generic_name’s link:

In conclusion, alcohol-based mouthwash consumption significantly increases salivary acetaldehyde levels in the first few minutes. However, no evidence exists if long-term salivary acetaldehyde levels may increase with a high frequency of mouthwash use. There is still insufficient evidence of whether the use of alcohol-based mouthwash is an independent risk factor for oral or oropharynx cancer. Nonetheless, it does increase the risk when it occurs concomitantly with other risk factors such as smoking or alcohol.

So no current evidence of alcohol-based mouthwash increasing oral cancer risk unless one also smokes or drinks alcohol, in which case one is already at risk.

Similarly, a more recent study confirms the same:

The use of alcohol-containing mouthwashes alone (when no other risk factors are present) does not increase the risk of developing an oral cancer or lead to increased salivary acetaldehyde. However, where other risk factors for oral cancer are present, the use of an alcohol-based mouthwash may further increase this risk.

While I am sure others may, I partake of neither alcohol nor smoking (nor do I have HPV, another risk factor), thus I feel relatively secure with once per evening use of a fluoride alcohol rinse, down from twice a day previously.


This topic reminds me a bit of something I observed as a kid. That every family has their own micro-culture. I was almost grossed out as a kid to learn my neighbors preferred Peter Pan peanut butter over Jif! Hahah. That seems pretty minor but I remember hanging out with them and it almost feeling like I was in another country or a bizarro world or something. Similar to my family but weird and different in little ways.


I’d have to agree that the jury is still out, and in fact my current dentist is the first one to suggest (to me) a link between alcohol-based mouthwash and oral cancer so I don’t know how widespread his belief is. Me, I’m going to play it cautious and avoid alcohol-based mouthwash anyway, if for no other reason than they tend to include artificial colors (and flavors?) that may be bad for you in one way or another.

I think this is a huge failing of society at large. For years dentists have been looking at my teeth and asking if I brush hard, to which my answer is always “no, but I probably did that years ago, before I knew how to brush.” In other words, the damage was done a long time ago, due to lack of training how to brush. People tend to think the harder they brush, the cleaner their teeth get. While that may be true in a technical sense, the damage done by brushing hard outweighs any benefit.

My dentist is also a huge proponent of bite guards, largely to protect against grinding your teeth at night. Again, this is the first time I heard such a thing. So I’m not sure if it’s something dentists tend to ignore because it’s not obvious (like a cavity) or if it just isn’t a thing (yes, I know everybody is different). Or maybe my dentist is just more on the ball about potential oral harm, and likes to err on the side of caution?


This one bothers me to no end! I was 30 years old before a dentist told me I was brushing my gums away and how to brush effectively to avoid gum recession. My anxiety dreams have definitely become more specific since then.