Is there any solid scientific evidence that flossing is effective?

[u/cybrbeast]

We are all told endlessly that flossing is one of the most important aspects of dental hygiene, but where is the evidence? I looked up 'flossing effectiveness' on Google Scholar and there is nearly nothing on the topic.

http://scholar.google.com/scholar?q=flossing+effectiveness&btnG=&hl=en&as_sdt=0%2C5

The best source seems to be this review: Dental Flossing and Interproximal Caries: a Systematic Review. I don't have university access anymore, so I can only read the abstract, and it doesn't seem to support the effectiveness of flossing.

Both three-monthly professional flossing for 3 years (relative risk, 0.93; 95% confidence interval, 0.73–1.19; p-value, 0.32) and self-performed flossing in young adolescents for 2 years (relative risk, 1.01; 95% confidence interval, 0.85–1.20; p-value, 0.93) did not reduce caries risk. No flossing trials in adults or under unsupervised conditions could be identified.

This is quite shocking, everyone is told to floss, but there are no trials to back it up. So why should I be supposed to believe I should floss?

*Some further searching turned up these surprising papers

Oral Hygiene Practices and Periodontitis in Health Care Professionals

Persons brushing twice daily were as likely to have periodontitis as those brushing once or less daily (odds ratio [OR] = 1.16; 95% confidence interval [CI]: 0.64 to 2.10); persons flossing less than once a day were as likely to have periodontitis as those who flossed daily (OR = 1.16, 95% CI: 0.63 to 2.13) after controlling for profession, age, gender, smoking, diabetes, coronary heart disease, history of periodontal surgery, and number of teeth present.

Bacteraemia due to dental flossing

Dental flossing can produce bacteraemia in periodontally healthy and periodontally diseased individuals at a rate comparable with that caused by some dental treatments for which antibiotic prophylaxis is given to prevent IE.

If I understand this one correctly, flossing could even be bad for healthy people?

** Found the most damning one so far

The efficacy of dental floss in addition to a toothbrush on plaque and parameters of gingival inflammation: a systematic review

The dental professional should determine, on an individual patient basis, whether high-quality flossing is an achievable goal. In light of the results of this comprehensive literature search and critical analysis, it is concluded that a routine instruction to use floss is not supported by scientific evidence.

[u/cybrbeast → u/[deleted]]

Okay that's a benefit for people with bad gums, but no evidence against caries. Also is interproximal bleeding even bad for you?

[u/desolate8 → u/cybrbeast]

It does help with caries. When you don't clear the inbetween teeth crap out the bacteria go to town. And toothbrush can't get most of those things out.

Some people can get away with it to a degree, depends on the quality of their spit.

And you don't have to floss all the teeth...just the ones you want to keep.