…In the last few weeks, I’ve had a few patients asking me what’s the purpose of dental floss and if it’s all in vain..! Some few went even further to give me that suspicious “hmmm -really?” look when I recommended interdental brushes! …and even the most disciplined of my patients have come across the thought that so many kilometres of this tiny white ribbon have been wasted in vain…
So, is it true? Has the world come upside down? Is flossing useless?
Well, to start with, don’t rush to flush the floss down the toilet..! Let’s give it a calmer thought! I think what we are caught up with in the case of flossing is not about a medical myth being busted, but rather yet another example of the so called “evidence based Hysteria”.
Evidence Based Medicine is a concept developed to free the world of healthcare from individual opinions of all sorts of “experts” , “gurus” and allow decisions to be based on unbiased, objective, scientific reserach data. Soon however, this noble cause was misinterpreted by some as the demand for the highest level of research in order to accept that a procedure is justified. The highest level of evidence is a Randomised Controlled Trial (RCT) , something that requires significant time and costs to be materialised and which in some cases is simply impossible for technical or ethical reasons. Full stop, emphasis on the “impossible”.
In the last few years however, many “hysteric” calls have surfaced about several medical procedures, implying that unless there is a prospective or randomised clinical trial to support it, a procedure is based on “weak” evidence or is unfounded.
It is well established that plaque is the cause of periodontal disease and similarly that flossing (or better “interdental cleaning” of which flossing is one way ) can disturb biofilm and prevent disease. Clinical and in vitro studies provide a good understanding for this. However, we do not have the highest level of evidence to prove it, like a randomised trial. This is simply not feasible. Such a trial would take many years and would need to involve many people, as periodontal disease is a very slow process. This people would have to be closely and prospectively observed, to comply for long periods with study requirements and many qualified clinicians to spend time to observe and record the data. The cost of such as study would be huge! The benefits? hmmm…
If you were a funding agency and you sit on one million dollars only, where would you chose to spend? In a study on pediatric cancer or a study about flossing?
Seriously! Furthermore, there is an ethical loophole, as such a study would require a group of patients to be asked to not clean between their teeth for comparison purposes, something no ethical committee will allow!
The recent “mythbusting” news was not saying that flossing does not work. It simply said that the quality of studies we have to show that flossing works is not of the highest level.
Sure. So what? Is flossing yet another conspiracy of the industry?
It is also true that we scientists have great responsibility when embarking on “mythbusting” Cochrane reviews, in order to prevent misinterpretations that actually will cause more public harm than benefit. Maybe it’s time to reconsider the purpose of spending time and man/hours on systematic reviews which merely just state the obvious.
At the end of the day, if the evidence for flossing is weak, is because none of us, Periodontists, bothered to produce it! So if you think a randomised clinical trial about flossing is what we need right now, please, go ahead and do it and show us all the truth.
The rest, in my humble opinion is just too much trouble for nothing.
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