So by now, most everyone in the country has heard the shocking and breaking news published by the Associated Press that stated that there is "weak evidence" that flossing actually reduces gum disease and prevents cavities, which then caused the federal government to drop flossing as a "general public health recommendation." Since we have had several patients ask about the report, I decided to write a BLOG that looks into the backstory behind the current confusion over the flossing debate!So how did all of this confusion come about? Starting with Mark Twain's famous quote about "lies and statistics," he used this phrase to talk about the persuasive power that numbers have and how they can be manipulated by individuals to push a public agenda, which can be used to describe the recent AP story by reporter Jeff Donn that has made big news regarding flossing these past few weeks!
Back in August of 2016, the AP released an investigative report citing "weak evidence" behind the importance of flossing. This report has been mentioned on more than 150 different news sites that have called into question the once-obvious recommendation by the dental community to their patients on the need for flossing to be included into their oral hygiene routines.
The background behind this AP report started in 2012, when an orthodontist who was treating the son of the AP Reporter Jeff Donn, asked if Donn would be interested in a story about flossing stating that there was no evidence that flossing actually worked. As an investigative reporter, Donn began reviewing the research on flossing. After prodding the federal DHHS agency, he received a letter of response stating that the committee had done no research on flossing, which caused the DHHS to quickly drop flossing from their "general public health recommendations."
In Donn's report, he states that he looked into 25 different studies on flossing and found that the studies "were unreliable" in their testing methods and/or "contained a large bias" as they were funded by flossing manufacturers. In his article, he implies that there is a definite financial motive to keep flossing relevant due the fees that the American Dental Association receives from each manufacturer that achieves and maintains the ADA seal of approval.
Although Donn is correct in stating that there is a shortage of good studies on flossing, he has done a disservice to the public by not explaining what statistics mean and how they can be used to show something as obvious as the benefits of flossing as invalid. When examining evidence-based medicine, typically there is a hierarchy of how studies rank in levels of credibility. The studies with the highest credibility/level of evidence are randomized, long term controlled trials, and those with the least credibility are expert opinions.
In addition, one of the problems with the "highest credibility level" trials is that they are very hard to conduct and can be extremely costly. Furthermore, short-term, case controlled studies or observations of proof by professionals are assigned a proof of "weak evidence" simply because they are not randomized controlled trials.
To prove the point on how statistics can discredit important data, a study was conducted on the use of parachutes to prevent bodily damage when descending from places of high altitude (i.e., jumping out of a plane). This study showed that because no randomized long-term clinical trials have been conducted on this subject, there was "a weak amount of evidence" to prove that parachutes prevented death and bodily trauma from gravitational challenges. This ridiculous conclusion was based on the fact that no good long term randomized controlled studies have been conducted on this particular subject. That same ridiculous conclusion can apply to the case for floss. Of the 25 studies that Donn looked at on flossing, many were flawed. Many of these studies were either short term, not well run, participants weren't given instructions on flossing, or the data was inconsistently recorded.
Unfortunately, what many people take away from the article written by Mr. Donn, is that a "lack of evidence" is somehow proof that flossing has no benefit. As in, no flossing is better than flossing if the evidence is not high quality. The bottom line is that a lack of high-quality evidence is not proof of ineffectiveness, especially when there has been little effort to obtain "high-quality" evidence to discredit the benefits of flossing in the first place. In other words, based upon the methods of conducting clinical trials, it may be true that "the evidence that flossing is beneficial is weak...but the evidence that it is NOT beneficial or harmful is even weaker."
Finally, when the AP Reporter Jeff Donn was asked during an interview if he would still floss in light of all of evidence that he presented in his investigative article on flossing, his answer was YES! Very interesting!!
Sorry that this BLOG has been quite a bit longer than my usual comments, but I really felt that the report needed to be thoroughly discussed and reviewed so that you could know the complete story! If you have any questions or comments, call our office at 918-455-0123!
God Bless,
DRT
