Well... has flossing been shown to be useful for human health? ETA: quick Google, found one meta-study. Results: "Trials were of poor quality and conclusions

Well... has flossing been shown to be useful for human health? ETA: quick Google, found one meta-study. Results: "Trials were of poor quality and conclusions must be viewed as unreliable. The review showed that people who brush and floss regularly have less gum bleeding compared to toothbrushing alone. There was weak, very unreliable evidence of a possible small reduction in plaque. There was no information on other measurements such as tooth decay because the trials were not long enough and detecting early stage decay between teeth is difficult." http://summaries.cochrane.org/CD008829/flossing-to-reduce-gum-disease-and-tooth-decay http://summaries.cochrane.org/CD008829/flossing-to-reduce-gu... So, pretty weak evidence, though perhaps mostly from lack of trying. It can't be considered as important as brushing. Then again, how do we know brushing is important? Time to find some other studies...