[npsimons]

Purely anecdotal, but I'm pretty sure I scrape some stuff off my teeth via flossing. In particular, there are areas near the rounded corners of my molars that, even after a good brushing, sometimes have stuff I can feel with my tongue. By looping the floss around as much of the tooth as possible and doing a few (not just one) up and down movements, it seems to get that stuff.

[beagle3]

But the question is, is that stuff bad for your gum or teeth health? That's not something you should assume a-priori.

An analogy: Whenever you bath with soap, you remove a layer of oil off your skin - a layer that your body puts there to keep you moisturized and hydrated. If you bath and soap too often, your skin will suffer, not improve, even though you're "cleaning" your skin.

[npsimons]

True, but the stuff on my molars feels similar to the stuff on my incisors after skipping brushing for a few days.