Dietary Guidelines Omit Flossing, but Patients Shouldn't
The latest version of the Dietary Guidelines for Americans issued by the US Department of Agriculture (USDA) and US Department of Health and Human Services (HHS) has given the brushoff to some time-honored advice: floss your teeth daily.
The change comes after a review of 25 studies published within the last decade suggested the evidence for flossing is weak, according to an article published by the Associated Press (AP). But medical and dental experts say the lack of a guideline does not mean patients should skip flossing.
"Our position is that flossing is still good," said Robert Wergin, MD, board chair and immediate past president of the American Academy of Family Physicians. "There's not much of a downside. Cleaning between the teeth is an important part of oral health, and good oral health is part of total health."
Dr Wergin told Medscape Medical News that the issue may be more absence of evidence, rather than clear evidence that flossing has no benefit. "One of my staff members conducted a literature search on the long-term benefits of flossing, and there wasn't a lot," he said. "There's no data that [flossing] is harmful, but are there evidence-based data to make recommendations [to floss]? No."
The AP conducted the review after filing a Freedom of Information Act request last year for the evidence used by the HHS and USDA to make the recommendation. Federal law states the dietary guidelines must be evidence-based.
The evidence for flossing is " 'weak, very unreliable,' of 'very low' quality, and carries 'a moderate to large potential for bias,' " AP National Writer Jeff Donn notes in a description of the review. He cites one paper in which the authors conclude that most of the studies fail to demonstrate that flossing helps with plaque removal.
The strongest evidence in favor of flossing was in a study of children 4 to 13 years of age with low exposure to fluoride. Professional flossing in that population every school day for 1.7 years was associated with a 40% reduction in the risk for caries (relative risk, 0.60; 95% confidence interval, 0.48-0.76; P < .001). Self-flossing, however, did not affect caries risk.
An HHS spokesperson explained in an e-mailed statement that "since neither the 2010 nor 2015 Advisory Committees reviewed evidence on brushing and flossing teeth, the authors of the current edition decided not to carry forward the information on brushing and flossing included in past editions of the guidelines. By doing so, they were not implying that this is not an important oral hygiene practice. It is also important to note that, although dental floss was mentioned in past editions of the Guidelines, it was most likely identified as a supporting recommendation along with brushing teeth, with the primary emphasis being on the nutrition-based recommendation to reduce added sugars." The 2010 guidelines mention flossing only once, as one of the components of an oral health regimen.
The type of evidence required for the dietary guidelines "cannot be obtained," Paulo Camargo, DDS, MBA, told Medscape Medical News. "Dental caries and periodontal disease take a long time to develop, so to really study the effects of flossing, researchers would have to compare people who floss to those who do not floss and follow them for many years, and that would be unethical." Indeed, many of the studies cited in the AP analysis followed patients for 6 months or less.
Oral diseases are caused by bacteria that completely cover the teeth, said Dr Camargo, chairman of the Department of Periodontics, University of California, Los Angeles, School of Dentistry. Anything that can get between and along the sides of the teeth helps disrupt this bacterial growth. Floss, interdental brushes, and even wooden toothpicks all are effective, "but flossing is easiest and least invasive. I think it's a disservice to patients to tell them they don't need to floss regularly."
"The success of flossing in preventing periodontal disease shows up over a lifetime," said Matthew Messina, DDS. Dr Messina, consumer advisor to the American Dental Association (ADA) and a private practitioner in Cleveland, Ohio, said he asks patients to brush their teeth and then floss, and to look at the debris flossing removes. "The ADA started advocating flossing in 1908, and it's been a tremendous success. We now have people living into their 80s and 90s and keeping most or all of their teeth. Why go back and re-research something when we know intuitively it works? We forget how much better Americans' oral health is today than it was 50 years ago."
But not everyone agrees those improvements are tied to flossing. "Oral health is better today thanks to the use of fluoride products and sealants, and less smoking, not the use of dental floss," said Philippe Hujoel, DDS. In fact, "the evidence is pretty good that flossing has not contributed to the improved oral health of Americans," continued Dr Hujoel, professor of oral health sciences and adjunct professor of epidemiology at the University of Washington School of Dentistry, Seattle.
The two main causes of dental disease are sugar and tobacco, Dr Hujoel told Medscape Medical News. He believes one danger of urging people to floss is that it may lull them into thinking it can compensate for poor lifestyle habits. "Flossing is definitely not a magic antidote if you continue to eat sugar and smoke."
Flossing does decrease gingival inflammation, Dr Hujoel said. "But don't make a leap of faith to say it prevents destructive periodontal disease; there's a lot of evidence that that's not true."
If patients eat an unhealthy, sugar-laden diet or smoke, Dr Hujoel urges them to use fluoride toothpaste and mouth rinses. Mechanical interventions such as brushing and flossing can help with bleeding gums.
Beyond that, he said, "you've got to tell the truth: there's no good evidence that flossing prevents cavities."
Bright Futures in Practice: Oral Health—Pocket Guide
The pocket guide is designed to be a useful tool for a wide array of health professionals including dentists, dental hygienists, physicians, physician assistants, nurse practitioners, nurses, dietitians, and others to address the oral health needs of pregnant and postpartum women, infants, children, and adolescents. It offers health professionals an overview of preventive oral health supervision and is designed to help them implement specific oral health guidelines. The guide includes information about family preparation, risk assessment, interview questions, screening, examination, preventive procedures, anticipatory guidance, measurable outcomes, and referrals.
In addition to this online version, Bright Futures: Oral Health—Pocket Guide, 3rd edition is also available in a PDF version, which can be downloaded for offline use, for example, in a reading app on a mobile device.
A Wisconsin clinic provides free dental care so that poor rural residents can get their teeth fixed. But in most states people aren't so lucky. Millions of people have no access to dental care.
Read this story
I had a conversation in a dentist’s chair on Tuesday morning that is echoing in my memory.
I’m new to this particular dentist, and so I had never before met the hygienist who would be responsible for cleaning my teeth. I shook her hand and learned her name – for the purposes of this story, let’s call her Emily – before she produced her tools and began to work.
In common with many medical procedures, there is something odd and awkward and intimate and vulnerable about dental work, there is something inherently goofy about a stranger digging around in your mouth. Most of the time, we fend off that goofiness by engaging in what our culture calls small talk, in conversations carefully designed to avoid big experiences and big feelings. During those brief intermissions when the dental tools are out of our mouths, we chat about our plans for the weekend or sports or the song that we just heard on the radio.
But on Tuesday, Emily and I accidentally touched on something big. I remarked to her that I had heard that dental care is hard work emotionally, that a disproportionate number of dental professionals are depressed because their patients are so often unhappy to see them. Emily agreed immediately, citing the famous and appalling statistic that tells us that the suicide rate among dentists is twice that of the rest of the population. And then she told me about an experience from her own life.
Emily had just graduated from school and was beginning her work as a hygienist. And she greeted the patients in her new workplace with enthusiasm. But she was continually surprised and disappointed by the dark cloud that folks carried with them into the office. Emily would say, “How are you?” to one patient after another. And one patient after another would reply by saying something like, “I’m good – but I’m sure not happy to see you.”
About a week in her new career, Emily abandoned the expectation that any of her patients would be happy.
She then explained that the reason that she was so surprised by her patients’ behavior in that first week was that, during her time in school, she and her classmates had cleaned the teeth of impoverished people. And all of the poor people who had come to see them had been profoundly grateful to have dental care.
Now, I’ve preached and written about gratitude a lot. Gratitude is one of my “go to” subjects; I agree absolutely with David Steindl-Rast when he tells us that gratitude is “the heart of prayer.” And so I will confess to being shocked by Emily’s words – or, more accurately, I will confess to being shocked by what her words told me about my own behavior. That’s because, like many of her patients – like many of you – I have had the privilege of having access to excellent dental care my whole life. And I’m embarrassed to say that I have taken that privilege for granted. Prior to sitting in that chair on Tuesday morning, I’m not sure that it had ever occurred to me to be grateful to be in a dentist’s office. I had always chosen to focus instead on the minor discomfort of having my teeth cleaned.
The irony is that I know a good number of people who have suffered from the absence of dental care. My own father, for instance, tells the story of enduring a paralyzingly painful toothache as a young man; I don’t even want to imagine what that kind of hurt must be like. I really like having a good dentist. I really appreciate the reality that, most of the time, the worst pain that I experience in my mouth comes from the occasional ice-cream induced brain freeze.
And so I want to take my conversation with Emily as a challenge. I want to extend my commitment to gratitude into the dentist’s office, I want to walk through its doors thankful that there are people who will help me to care for my teeth, I want to remember the lesson taught to us by the impoverished folks who come to the dentist full of thanksgiving.
Next time, as I sit down in Emily’s chair, I want to be grateful to see her.
The Rev. Martin Elfert