The AP asked the government for proof that flossing works. The answer: ¯\_(ツ)_/¯ | Hacker News Reader

The AP asked the government for proof that flossing works. The answer: ¯\_(ツ)_/¯

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24 pointssharkweek13 comments

I suspect that our biggest dental hygiene issues originate from sugar decaying our teeth. Maybe I should ask my dentist.

This is odd to admit but I went a year without brushing / flossing my teeth, then went to the dentist and asked about my plaque build-up. Negligible. When I told them about this experiment they were disbelieving.

I attribute it to my strict diet at the time: Keto, no products with added sugar. Few fruits. Mostly vegetables, fats, and some meat. Certain foods would cause bad breath so I limited consumption of those at key times.

Please floss. If you don’t, try it and then smell it. You’ll want to start

You’re telling people to not trust science, just trust some unscientific proxy test. That’s how you get to Feng Shui, homeopathic drugs, ear candling and bleach enemas.

If the statement were so obviously true, it wouldn’t be hard to prove through research. It isn’t so it isn’t actually obviously true.

Not flossing is a frequent root cause of gingivitis, which can degrade to periodontitis and subsequent tooth loss due to damage to the bone that holds your teeth.

If that is really true, it should be pretty easy to show in scientific research, right?

The issue with the article here is that AP asked the government about research concerning this issue instead of, you know, a dental institute.

Which is akin to asking McDonalds about research on asphalt.

You may have skipped reading the linked AP article as the url has changed, the new one is:

https://apnews.com/article/f7e66079d9ba4b4985d7af350619a9e3

Most of the research is sponsored by the manufacturers so if anything you’d expect it to be slanted towards showing positive results. But instead

‘The evidence for flossing is “weak, very unreliable,” of “very low” quality, and carries “a moderate to large potential for bias.”’

The article does read like it's pointing out the lack of randomized controlled trials for parachutes:

https://www.bmj.com/content/363/bmj.k5094

People don't pay for studies of something they think is obvious. That's why you get only poor-quality studies. Dentists can tell who's flossing and who's not just by looking, and they know that their healthier patients floss.

It's not impossible that they're being misled, but it seems more that it's just old but correct observational wisdom that predates modern methodology practice. And if it's wrong it would take a fair bit of effort to disprove it -- so nobody bothers.

> People don't pay for studies of something they think is obvious.

Then why do they pay for a study of the effect of flossing? And why is the result that it really doesn’t help a lot?

> Dentists can tell who's flossing and who's not just by looking, and they know that their healthier patients floss.

But can they? Or do they see someone with healthy teeth and say it’s someone who flosses correctly?

I think most of those poor-quality studies are something they can show the FDA: "We want to put this new variety of dental floss on the market. Here's the crummy study we did showing a bare minimum of effort. Can we?"

(I don't know much about dentistry, but that's what they do with new food ingredients and supplements, with which I have a little familiarity.)

As for dentists, yes, they ask people about their flossing habits. That's not as good as a formal mathematical study, but we're talking about so many people that a real effect would be obvious.

(We put too much weight on statistical significance. It's great to have a rigorous process, but in a lot of ways, if you can't see the effect at a glance, then it's not really going to do all that much good. We have a number of drugs that are better than placebo or alternative drug, but not that much better.)

Right, you don’t know much about dentistry but this is what you think is obviously true, never mind that science shows it’s not.

Anecdotal, but I've never flossed (outside of the dentist's office) and everything is fine. Perhaps some people need to floss more than others?

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