- It's irrelevant to know if flossing "improves" overall health...what is relevant is that it will not worsen it, and you are removing rotting stuff from your teeth, and worst case scenario you just waste 2-3 minutes and have a more pleasant breath..why overcomplicate things?
It doesn't worsen your health, it either does nothing or improve it, so it is reasonable to do it
Medical literature is full of these things: do you need people to prove it with several studies that it's good for you to go for a walk every day? Try to weight the cost-benefit of your actions...if the cost is small, the risk non-existant, and the potential benefit high, it's usually a good idea
There are thousands of wives tales and pseudoscience remedies I don't need to waste my time on. If not backed by actual science, this type of recommendation is no better than any of them.
Basically, good current dental hygiene practice is to brush and floss like the experts tell you.
Of course it is difficult to definitely prove whether or not vitamin C supplements reduce the duration of a cold. That doesn't mean that we should all just abandon empiricism and start gulping vitamins because it is "common sense."
What if someone's "common sense" leads them to believe that use of a an abrasive cleaning technique like flossing might damage their gums? I can think of any number of non-scientifically backed rationalizations one could use for or against flossing.
So, even if not-definitive, what research is there on whether flossing improves oral or overall health?