[msteinert]

I believe the logic goes something like this: Research shows that perio disease may be linked to heart disease [1]. Flossing has been proven to reduce your chance of heart disease so it also reduces your chance of heart disease.

I'm not going to try and dig up a bunch of studies to back this up. I drank the Kool-Aid years ago. It appears to have paid off for me in the dentists chair!

[1]: http://www.perio.org/consumer/heart_disease

[schoper]

Correlation. Causation. Not the same.

People who floss twice a day tend to have all sorts of good habits. In fact, they tend to be the sort of people who just plain "take care of themselves."

[msteinert]

Agreed! For the causation you'll have to read the extensive literature on periodontal disease.

[run4yourlives]

Which won't help much, given that the second line in your link is: While a cause-and-effect relationship has not yet been proven

[msteinert]

Agreed, the cause and effect between heart disease and periodontal disease is not well proven. However, the beneficial effects of flossing in preventing periodontal disease is well understood and you're welcome to read the literature yourself if you don't believe me. I believe this is exactly what I said in my original comment.