Dublin dentists have their say on flossing stories

Dr Richard Lee Kin and Dr Barry Dace give their thoughts

Two Dublin dentists who limit their practice to periodontics, have their say on the recent flossing stories in the media:

Dr Richard Lee Kin, whose Dublin practice is limited to periodontology and implant dentistry said: “It’s great to see a discussion on oral hygiene in the media and it has captured the public’s attention.

“The current evidence supporting flossing is weak, however, that does not necessarily mean there is no association. There is no evidence that flossing doesn’t work either.

“Long term double blinded studies are needed, but they are likely to be unethical and getting approval is going to be unlikely.

“There is no doubt that biofilm disruption through mechanical plaque control and personal oral hygiene is an integral part of periodontal therapy.

“As each patient is unique, a specific oral hygiene strategy tailored to the individual is key. Their therapeutic response to therapy can be evaluated and modified as necessary and that strategy, I believe, still includes flossing. It removes interproximal plaque and reduces inflammation, particularly in those areas that are inaccessible e.g. severe imbrication.

“Practically speaking, it is also not time consuming and inexpensive for the patient.

“Given that the vast majority of individuals are unable to demonstrate optimal oral hygiene, flossing still plays an important but perhaps less significant role.”


Dr Barry Dace, practice limited to periodontics, Blackrock, Dublin, said: “The recent Associated Press (AP) investigation into the evidence supporting the benefits of dental floss, and subsequently the dropping of flossing from the recommendations of the US government departments of health and human services and agriculture, raise some interesting points in our era of evidence based dentistry. In dentistry and medicine, its so important that we base our recommendations on sound clinical evidence – no matter what the conventional wisdom might be.

“It’s important to remember, in this case, that the US government departments are not dropping flossing from the recommendations because it doesn’t work – they’re saying that we just don’t have good enough studies to stand over claims that it has such benefits. Indeed, much of the research on flossing is of poor quality, often in the form of short-term studies on healthy subjects, and often funded and carried out by the manufacturers. What we really need are independent large-scale studies, over a long period of time, to truly see if there are dental health benefits for flossing. It takes a long time for periodontal problems to develop, we simply don’t know whether daily disruption with floss will prevent that, as the available studies are too short in duration to assess it.

“These are very difficult, time consuming and expensive studies to undertake – and there are precious few of these around to help us make recommendations for the general population. So, it may be some time before we know the true answer to the question of whether flossing really does prevent cavities and gum disease from forming.

“And this is the difficulty with interpretation of such decision processes through the filter of the media. We careered from this complex issue about a lack of evidence, to stories about how floss doesn’t work, and in two reports that I read, how floss can be dangerous, even causing bacteria in the bloodstream. We all know that if you have gum disease, even brushing your teeth (or indeed chewing) can cause transient bacteraemia, but of no significance for the vast majority of incidences.

“So, my concern here is that the media distillate of this story contorts the issue so much that it becomes counter productive to the population who can’t (quite rightly) interpret the information.

“Now, to get back to what to say to patients who ask us. We know that floss will disturb plaque between tight teeth. Since plaque is necessary to cause gum problems and cavities, our best guess (in the lack of evidence) is that such cleaning is probably helpful, and is easy to do. But, if the gaps between teeth are wider (as is more often the case in adults) then there are better ways of removing plaque from between the teeth – such as little interdental brushes.

“Lets not forget though, that when gum disease is present (as in an alarming percentage of our adult population), it has to be treated by us as professionals, as chastising patients for their lack of flossing will never address this.”