Is Flossing Necessary to Prevent Cavities?

Every time I go to the dentist I get badgered on how I need to floss more. Floss, floss, floss and every time I leave the dentist I tell myself I’m going to floss every single day. That usually lasts for about eh… a week. I’m horrible at staying on top of my flossing habits. From a person who has never had any cavities though (jinx, knock on wood!), I wonder if there is truly any correlation between flossing and getting cavities. My mom always tells me to floss so I don’t get cavities but so far, for 18 years I’ve been doing pretty well with minimal flossing.

Here we have four possibilities:

  1. Lack of flossing causes cavities (Direct Causation).
  2. Cavities cause a lack of flossing (Reverse Causation).
  3. A third variable like poverty causes both cavities and a lack of flossing.
  4. The correlation between flossing and cavities is due to chance alone.




First let me explain to you why dentists insist on flossing. According to bbs’s article titled Should you floss or not? Study says benefits unproven, dentists claim that flossing between your teeth removes plaque and food build up. They believe that the removal of plaque will decrease the chances of getting cavities or gum disease. According to the bbc article though, the Associated Press says that the American Dental Association’s claims about flossing are old.

So where did flossing come from? According the bbs’s article Should you floss or not? Study says benefits unproven, flossing began being promoted in 1908. Way back in the 1800’s though is when Levi Spear Parmly invented flossing. So as you can see, flossing has been around for a very long time.


Levi Spear Parmly

In a recent Washington Post article by Timothy Levine, he mentions that the ADA (American Dental Associate) and the American Academy of Periodontology admitted that there is a lack of knowledge when it comes to the history behind flossing, but they still recommend it. Sounds a little weird right? Even though flossing was invented a long time ago, there is still no scientific reasoning behind it. It’s based on an anecdote alone (Levine 2016). Keep in mind that Andrew mentioned in class how anecdotes tend to be weak inferences and lack a lot of certainty.

In 2006, there was a study conducted to test the correlation between flossing and the chances of a cavity according to a Forbes article titled Dentists Say You Need to Floss. Science Says You Don’t. According to the author, Steven Ross Pomeroy, the study was conducted with children ages four to thirteen. Half of the students got their teeth flossed professionally for 5 days of the week for 1.7 years. Those kids had a 40% decrease in the chance of getting cavities in contrast to the kids who were taught to floss and did it on their own. Those kids had no reduction. This shows that letting kids go off and floss on their own is as beneficial as having them not floss at all. The problem they found with this study though was that they could not trust that everyone was brushing correctly with fluoride. That made it hard for them to determine if flossing did anything as an addition to brushing well with fluoride (Pomeroy 2013).

Tooth decay


In 2012 an experiment was published, seeing the effects of flossing in addition to brushing on gingivitis and plaque buildup (Levine 2016). In the scientific study, mentioned in the Forbes article by Steven Ross Pomeroy, there were 582 participants who were flossing and brushing in opposition to the 502 (the control group) who were just brushing. Of the 12 trials that were conducted, only 7 of them had no big bias. From the results, the study in the Forbes article showed that flossing and brushing was better in prevention of gingivitis (but very minimal). When it came to plaque reduction, there wasn’t really much evidence to support that flossing in addition to brushing helped with plaque reduction according to the study mentioned in the Forbes article by Pomeroy.

In the end though, although the studies are unreliable, you should still floss. For the sake of avoiding gingivitis and for precautionary measures just floss because there’s really no cost and a few low risk to flossing, according the bbc’s article. In a way, the reasoning behind why you should still floss is similar to the pop quiz we had on the mice and if exposure to dim light at night caused depression. It’s extremely easy to just close the blinds, just like it is extremely easy to floss to avoid a possible future issue. Again, we should keep in mind that flossing has been proven to cause gingivitis according to The evidence for flossing’s benefits is not good enough. But it’s all we’ve got by Timothy Levine. Beyond that, it has been said that gingivitis leads to periodontitis, an intense gum disease, that can easily be avoided with flossing (Levine 2016). Floss your teeth as a precautionary measure, but don’t freak out if you haven’t been flossing all along!


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5 thoughts on “Is Flossing Necessary to Prevent Cavities?

  1. lkr5215

    i totally see where you are coming from with the dentist thing. I also get told all the time to floss though i do not really floss. I currently have no cavities but have had some in the past. Maybe my experience can be something to consider when discussing flossing. My dentist always just says to floss or rinse with mouth wash. Will i floss after reading this blog? it made me consider it more than it did before when a dentist would suggest it. It also surprises me there is not a real reason behind flossing other than it being highly recommended.

  2. Allison Maria Magee

    This topic is very interesting to me because it seems I have had a similar experience to you. I have never had a cavity and every time I visit the dentist, they remind me that I should be flossing everyday. I know I should be flossing but I always seem to forget, and I feel that it is even harder to remember now that we are living in a dorm. I found an interesting article that shows a black floss that was invented in order for the flosser to be able to better see the plaque coming off of their teeth. I find this an interesting concept!

  3. Kate Billings

    Hi Jillian! I completely relate to your feelings about flossing. Every time I got to the dentist they tell me to keep up my flossing (even thought I haven’t been flossing) and to floss more regularly. They say that flossing prevents cavities yet being honest with myself and my dentist I don’t floss regularly. I have always been a little skeptical of flossing and the information in this post doesn’t surprise me. I know that my mom has always told me to floss but I really am not sure there is a correlation between flossing and the reduction of cavities. I was a little surprised to read that there is no scientific reasoning behind flossing. You would think that if dentists are telling all of their patients to floss they would have science to back up their reasoning as to why they tell people to floss. Maybe flossing doesn’t do anything at all. It’ll be interesting to see if any developments on this topics come up in the future.

  4. Sean Kyle Reilly

    Hey Jillian!

    One thing to keep in mind about dental industry is the fact that they are just that – an industry just like hundreds of others. They market their products for consumption in the name of health benefits, and act as a key third variable to your findings. Maybe dental offices have some type of partnership with specific dental brand companies, such as Colgate-Palmolive or Johnson and Johnson, and are sponsored by them? Ultimately, there is hardly enough evidence to support not flossing, yet, do not rely solely on opinions of dentists and others in the industry, as they may have an inherent bias for the continuous use of a product known to hardly benefit our livelihood. Always look into the source behind these studies and findings, and continue to question their relevance in today’s modern practices.

    Otherwise, I found your post to be informative about the topic of flossing. Well done, and best of luck with the rest of the year!

  5. Alex Felton

    This topic is so controversial especially because I was just told I had a cavity due to lack of flossing. I think evidence could possibly change and maybe flossing is just an old-school method of keeping your teeth clean but I agree with the low cost of flossing to potentially avoid the damaging effects. Great post.

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