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March 01, 2017

Infrequently Asked Questions: Do I still need to floss?

Don't toss the floss just yet

The Associated Press dropped a bombshell report last summer when one observant reporter noticed flossing had been dropped from federal dental guidelines. It sounds like cause for celebration, but is it really?

Eager to get the lowdown on whether flossing is still recommended, we reached out to Jefferson University Hospital oral and maxillofacial surgeon Robert Diecidue. 

What's the harm of not flossing?

Bacterial plaque is an important etiologic factor in gum inflammation which if left untreated can eventually lead to bone loss and gum disease known as periodontitis. Studies in the past have looked at tooth brushing alone as a method of removing plaque from around teeth surfaces. Toothbrushes are ineffective in reaching the interproximal spaces (areas between teeth) and even after brushing, a small film of plaque can easily be left behind.

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As this plaque continues to build, the type of bacterial colonies within transform from ones that thrive in the presence of oxygen (Aerobic) to those that thrive in its absence (Anaerobic). Certain types of anaerobic bacteria in these transformed colonies have been scientifically linked to the presence of gum disease. In order to prevent bacterial colonies from transforming, cleaning of plaque from spaces between teeth is essential. Flossing mechanically disrupts these bacterial colonies in areas where a toothbrush is unable to reach. The end result is a healthier, cleaner mouth with less inflammation and at decreased risk for gum disease.

Last summer, the Associated Press posted a report claiming there's actually very little evidence to support flossing as beneficial to oral health. They also noted that the federal government removed it from its list of recommendations. What's your response or reaction to that?

If there is little evidence to support flossing as beneficial, there is absolutely no evidence which states it is harmful. Flossing mechanically disrupts the formation of plaque which is due to food particles that are left trapped in spaces inaccessible with just a toothbrush. If the risk of gingivitis is reduced even minimally with flossing, that reduction is worth the effort.

A lot of the report emphasizes that studies are insufficient in how they've tested floss, using small sample sizes and just simply not doing enough studies. Is there one study, though, that you think is pretty illustrative of the benefits of flossing?

Flossing is a technique sensitive intervention which is difficult to observe and study. However, the benefits of professional flossing have been studied in children and the results show when professional flossing is done five days a week, there is a statistically significant reduction in cavities found in between teeth surfaces.

What's the general theory behind flossing's benefits?

The ability of floss to reach food particles in spaces not cleaned by tooth brushing alone prevents the formation of a plaque layer which over time can lead to gum inflammation. As this plaque accumulates, inflammation increases causing bleeding from gums and over time bone loss is observed around teeth.

Do people ask about flossing more now that this report's out?

Most people still continue to floss despite the report. Even minimal benefit can potentially lower the risk of gum disease

So if nothing else, it's fair to say it's better to floss regardless, no? It's certainly only helping to remove food debris.

Absolutely. Establishing a flossing routine in addition to tooth brushing will only help decrease inflammation and hence reduce the risk of gum disease.

Is there a best time of day to floss? For example, maybe you're not actually accomplishing much if you eat yogurt for breakfast and floss after. You're not exactly flossing out as much as you would after eating a burger.

Ideally, flossing after meals would provide maximal benefit. But since this may be too cumbersome, flossing at night may prove most beneficial.

Do you think the poor results from studies might just have to do with people improperly flossing?

Flossing, as mentioned earlier, is a technique sensitive intervention and thus hard to study. Not every study participant can be monitored for technique. It may be worth the effort to learn the method and skill appropriately at your next dental visit.