How does flossing help to prevent tooth decay and gum disease? -

Knowing how flossing prevents dental disease will help you understand what you need to accomplish when you floss.

The ins and outs of flossing to prevent dental disease.

While it may not surprise you to learn that tooth decay and gum disease can be prevented by flossing, there's a good chance that you don't really understand the specifics involved with each, and how ineffective flossing habits can ultimately still leave you at risk for both.

Only the use of proper flossing technique can lead to prevention success.

Practicing effective flossing takes a lot more than just slipping your dental floss between your teeth and then back out.

Instead, it requires the use of the floss in a methodical manner. One where it's used to scrub and clean the full extent of those tooth surfaces it can reach, and especially those that your toothbrush can't.

But accomplishing this doesn't have to be all that difficult.

When it comes to preventing tooth decay and gum disease, there are specific locations where plaque build up between teeth most frequently causes problems.

So even though your flossing results need to be meticulous, if you know where to focus your efforts, accomplishing a high level of effectiveness can be much easier than you might expect.

And that's the goal of this page. Outlining for you those locations where plaque accumulation between teeth is most likely to be troublesome, so you're sure to get those areas clean when you floss.


Locations where dental plaque tends to accumulate between teeth.

When it comes to understanding how plaque causes gum disease and cavities, it's necessary to understand the locations where it tends to accumulate, and what tends to occur if it does.

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Protected locations for plaque accumulation between teeth include their contact point and under the gum line.

Areas of concern and their possible related consequences:

  • Plaque accumulation at the contact point of adjacent teeth. - (Pointed out by the upper blue arrow in our illustration.)

    Dental plaque accumulation at the contact point is typically the cause of cavities that have formed in between your teeth.

    In fact, the routine (bite-wing) x-rays that dentists often take at 6 or 12 month intervals are specifically taken so they can evaluate this location (especially with children, but with adults too).

  • Plaque that accumulates subgingivally. - This is that below-the-gum-line space that exists between a tooth and its surrounding gum tissue. (Pointed out by the lower blue arrow in our illustration.)

    It's the waste products of bacteria that have colonized this area that are responsible for causing gum disease (gingivitis, periodontitis).

    Removing dental plaque from this region is so important that any periodontist (gum specialist) will volunteer the information that curing your gum disease is essentially impossible unless you start to do so.


Our categorization of just two locations is overly simplistic. Dental plaque forms a continuous film, of varying thickness, on all in-between-the-teeth tooth surfaces. But the two areas we have mentioned are especially notable and problematic when it comes to the formation of dental disease as we've described above.

They also happen to be two very protected locations, in the sense that other than by using dental floss it's essentially impossible to cleanse them. This is an astoundingly important point to realize.


A) How flossing helps to prevent tooth decay.

The process of cavity formation will only take place during those periods when a tooth's surface is covered with dental plaque.

  • When plaque is present, the decay process has a chance to progress. (This is referred to as demineralization.)
  • When the same tooth surface is plaque free, it's possible for a healing mechanism to take place that helps to reverse the effects of cavity formation. (A process termed remineralization.)

This is why you brush and floss.

As far as preventing tooth decay goes, this is pretty much what tooth brushing and using dental floss is all about.

These activities help to minimize the amount of time dental plaque is on teeth so the scales are always tipped in favor of the healing process rather than cavity formation.

Persistent plaque accumulation at the contact point can lead to cavity formation.

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Flossing to prevent cavities.

Where most cavities form.

As previously discussed, a location that's particularly vulnerable to cavity formation is the point of contact between two adjacent teeth. (The circled area in our diagram.)

Fortunately, almost any flossing technique, even the most haphazard, tends to clean this region. That's good because this is an area where the bristles of a toothbrush literally can't reach.

Areas where cavities can also form.

We should also mention that while not classically the most at-risk region, those in-between-the-teeth portions of a tooth's surface that lie beyond the contact point can be at risk for decay too.

Only a technique that includes pulling the dental floss up against the tooth's surface and working it up and down will be effective in cleaning these areas and keeping the person safe from decay.

B) How flossing helps to prevent gum disease.

Plaque that has accumulated below the gum line must be removed.

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The dental plaque that accumulates on a tooth's surface at and below its gum line can lead to the formation of gum disease.

Plaque accumulation below the gum line leads to the formation of gum inflammation.

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How? / Why?

Dental plaque doesn't just contain bacteria. It also harbors the waste products and toxins they have produced.

Each of these is a tissue irritant that can trigger an inflammatory response in a person's gums.

Some of the signs of this inflammation (which is actually gum disease) are tissue redness and swelling.

Additionally, inflamed gums are often tender and tend to bleed when a person brushes or flosses their teeth.

What flossing technique is needed to prevent gum disease?

Many people, including a large portion of those who do floss regularly, simply don't understand what steps are needed to clean away the dental plaque that's most likely to cause gum problems. (Specifically, plaque that has accumulated in the areas outlined by the circles in our illustrations.)

The solution is to floss "subgingivally" (meaning using the string to scrub and clean the in-between-the-teeth portions of each tooth that lie at and below their gum line).

Doing so takes a little bit of effort and time but it's vitally important to do so. For details how, we provide instructions on this page.

Flossing regularly may help to keep you in good physical health.

Researchers have identified a statistical relationship between having gum disease (periodontal disease) and experiencing heart disease, stroke, or pregnant women delivering prematurely. However, these studies have not positively identified the underlying basis of this correlation.

One theory blames the persistent state of inflammation that occurs with gum disease. It suggests that chemical mediators associated with gum inflammation wind up distributed throughout the person's body via their blood stream. These chemicals then in turn have a contributory impact on inflammatory diseases already taking place in other parts of the person's body.