The following post is a collaborative effort between myself and science-based dentist Grant Ritchey DDS. Dr. Ritchey is a co-host of the always excellent The Prism Podcast, most recently interviewing Dr. Robert Weyant and discussing how to teach critical thinking to dental and medical students. He can also be found on Twitter at @SkepticalDDS. Dr. Ritchey has written for SBM before on the topic of cranial osteopathy in dentistry.
As a pediatric hospitalist, I don’t deal with issues of dental health very frequently. Sure I see plenty of oral mucosal lesions, as occur during a primary herpes outbreak or a case of Kawasaki disease, but not many problems with the teeth themselves. I do admit a few dental abscesses here and there that need to be cooled down with IV antibiotics prior to definitive surgical drainage. And as a hospitalist that sees a fair amount of newborns, I also discover the occasional natal tooth. That’s when a baby is born with a tooth, usually a central mandibular incisor, having already erupted.
But as a pediatrician, I care deeply about the overall health of children and the network of caregivers that surround them. I guess you could say that I take a holistic approach, but I would prefer that you didn’t. Although we aren’t dentists, pediatricians recognize that oral health is integral to the well-being of a child and that many long-term dental maladies develop during the first two decades of life, often before the first tooth even appears. The most common, and one which non-dentist health care providers can have a major impact on, is the development of dental caries, or “cavities”.
Why not just let dentists take care of teeth?
Again, pediatricians are interested in every aspect of the health of their patients. Non-dentist health care practitioners that see kids also typically have access to them long before they ever see a dentist. The American Academy of Pediatrics (since 2003), American Academy of Pediatric Dentists and the American Dental Association all recommend that children be seen by a dentist at or near their first birthday, which leaves a lot of time for problems to develop. And pediatricians are often asked about dental health, particularly about fluoride and brushing.
It is critical in the first year of life for assessment of risk, and intervention in high risk patients, to be performed in order to prevent tooth decay. And it can be prevented. But there are a number of stumbling blocks that prevent children from receiving appropriate dental care. In many areas, dentists will not see young children, and the nearest pediatric dentist may practice a few towns over, limit what insurances they accept, or simply be too swamped to accept new patients. It is often very difficult for children of any age that are on Medicaid to find a dentist, and even when there is availability many parents don’t think of early dental care as a priority so they don’t make the appointment.
But some pediatricians are also to blame. Until 2003, the AAP did not recommend that most children first see a dentist until age three. And as with many aspects of medical care, there has been sluggish adoption of new recommendations by established practitioners. So the pediatrician and family doctor often find themselves providing dental care and education on cavity prevention.
What is dental caries and who gets it?
Simply put, caries is tooth decay. Often called a “cavity”, caries is actually one of the most common infectious diseases in humans, right up there with the common cold. In fact, it is the most common chronic disease in the pediatric age group. The process starts early, often in the first couple of years, and almost nobody is spared. Roughly 90% of us will have some degree of tooth decay during our lifetime. The other 10% must be on the Paleo Diet. I kid. Want an easy way to know if your diet is probably bogus? If it’s capitalized. Nobody capitalizes “the eat fewer calories” diet.
Breaking incidence down by age groups shows a steady increase in the prevalence of caries over time, which makes sense because a large portion of the risk is related to repeated exposure to cariogenic foods (sugar) and the bacteria that love them. The National Health and Nutrition Examination Survey (NHANES) III revealed that about a quarter of children ages 2 to 4 years were found to have decay in their primary, or “baby”, teeth. This increased to half of kids aged 6 to 8 years and roughly 60% of adolescents, with these being secondary, or “permanent”, teeth.
Rates of caries are higher, and it occurs much earlier, in the poor. Not surprisingly, it also tends to be worse. There are significant numbers of children out there not receiving any treatment for their dental decay, but poor children are considerably more likely to slip through the cracks.
But we are all at risk for the development of caries, even the most wealthy and privileged among us. But certainly some individuals are more prone to decay for a variety of reasons. As mentioned above, folks below the federal poverty line are more at risk and those above 200% of it are somewhat protected. The reason for these trends, though not completely understood, is likely the impact of the mélange (calm down Dune fans) of variables unique to groups, such as cultural practices, education, diet, hygiene and the availability (or lack of) dental care.
There are a number of additional risk factors which are child- or caregiver-specific. Kids who have had caries in the past are obviously more likely to develop it again. Children with visible dental plaque, who frequently expose their enamel surfaces to sugar, who don’t brush regularly and who have inadequate fluoride exposure are also at increased risk.
Remember that this is considered to be an infectious disease, and kids frequently swap oral flora with their parents. For this reason, I do not recommend spit cleaning a pacifier, but particularly if the caregiver has problems with caries. It appears that the worse off a caregiver’s mouth is, the more likely their child will develop decay, and this may be from spreading around cariogenic bacteria. This includes having multiple involved teeth and actual tooth loss. Modeling of behavior likely plays a big role as well. Parents who brush less than the recommended two times per day, or who express a lack of concern regarding oral health, teach their kids to do the same.
But it gets even more complicated because there is emerging evidence that genetics may contribute significantly to the risk of developing caries as well, perhaps as much as 50%. How the tooth is formed, the composition and flow of saliva, the affinity for ingesting high sugar foods and the immune response to the presence of cariogenic bacteria all likely play a role. Tooth decay truly is a complex, multifaceted process that clearly isn’t as simple as forgetting to floss every day or even the socioeconomic status.
The goal of dentists, and ideally all pediatric healthcare professionals, is to prevent the development of caries in the first place. And again, this is very possible. But as the numbers show, this rarely happens. Many of the risk factors listed above, which are more fully fleshed out by the American Academy of Pediatric Dentistry’s Caries risk Assessment Tool, are based on clinical findings or established habits and dentists are often playing catch up anyway. A great deal of damage has already been done by the time a child is seen in their office, with many children only referred to a dentist once there are complications.
Risk assessment ideally should take place before the first eruption of teeth, or very soon after, so that children at high risk for caries can be referred to a pediatric dentist, or at least one that will see an infant. Placing all children who live below 200% of the federal poverty level on the most intense caries prevention program is probably the easiest approach, but is likely not cost effective. Combining this with questions about the dental health of biological parents is probably the best means of flagging high risk kids. If done right, when the first teeth begin to appear sometime between five and eight months of age, true primary prevention can be initiated.
There are a few other risk factors for tooth decay which should prompt a referral to a pediatric dentist, if available. These include breast or bottle feeding past a year, use of a bottle at bedtime, visible plaque and enamel pits or defects. If there isn’t a dentist that will see a high risk child, which as you now know is fairly common, there are caries prevention strategies besides just education that can be implemented in the non-dentist’s office, the best for a variety of reasons probably being the application of a fluoride varnish. I’ll discuss this at length in a bit.
Why do we care about tooth decay?
Ultimately, untreated dental caries leads to loss of teeth. This is commonly seen as a minor inconvenience in children, with many unfortunately considering it to be a sort of rite of passage. In some communities I believe that a learned helplessness has set in, and the rotten teeth and subsequent telltale mouth full of silver crowns is accepted as inevitable. In my home town of Baton Rouge, this is an extremely common site. But although important for a variety of reasons (chewing, speech development, holding a space for adult teeth), those are typically primary teeth and will be replaced by an adult version. Loss of adult teeth is a much larger concern because we aren’t sharks. With rare exceptions, there are no more in the pipeline.
In children with untreated tooth decay, toothache is common with pain emanating from the tooth leading to thousands of emergency department and primary care practitioner visits each year. As untreated caries progresses, inflammation and infection of the gums (gingivitis) sets in, potentially followed by involvement of deeper tissues and surrounding bone (periodontitis). Or the tooth can just become loose, because the periodontal ligament is involved, and simply fall out. Finally, an abscess can form in the tooth or surrounding tissue that requires surgical intervention and sometimes admission to a hospital. Kids miss school. Parents miss work. All this costs money, but tragically this is still not the worst complication.
Here is a 2007 case where a child died because of untreated caries which apparently led to meningitis or a brain abscess. It’s difficult to tell from the article. But it highlights the issues I’ve raised very well. The author states that “Deamonte Driver’s life could have been spared if his infected tooth was simply removed– a procedure costing just $80.” While true, it’s important to point out that his life would likely also have been spared if he had been appropriately flagged as high risk and had a fluoride varnish applied by his pediatrician or family doctor, or perhaps even just counseling on better oral hygiene.
Tooth anatomy (Ritchey)
There is a large subset of children who see their pediatrician but don’t regularly see a dentist. And to dovetail with what Clay has already discussed, I think it would be worthwhile to briefly describe how fluoride works to reduce the incidence of dental caries, because fluoride is the best weapon in our arsenal against tooth decay and is something that can be understood and put into use by health care practitioners who didn’t go to dental school.
As we all learned in grade school and demonstrated in our 4th grade science fair projects, tooth enamel is the hardest substance in the human body. It is the translucent, whitish covering of the crown of the tooth, that part that is above the gum line. It averages a millimeter or so in thickness and protects the softer underlying dentin and pulp (nerve) tissues.
Tooth enamel is composed of approximately 96% minerals, with the rest consisting of water and a small amount of organic material. If you want to impress your friends at parties, you can nonchalantly drop that enamel is a crystalline structure composed of hydroxyapatite (HAP), arranged in parallel “rods” that extend from the external surface of the tooth toward the center. While this extremely hard hydroxyapatite structure allows us to chomp ice and have a dazzling smile, its Achilles’ heel is that it is susceptible to erosion from acids and mechanical forces (e.g. chewing, aggressive toothbrushing, etc.), in much the same way that acid rain and years of footsteps will erode the limestone steps of an old building. Once this demineralization occurs, it becomes a site where further bacterial colonization can occur, and when this happens, you have a cavity!
Role of fluoride
This is where fluoride comes in. Tooth enamel, when exposed to fluoride either systemically during tooth development or topically via toothpaste, fluoridated water, or professional application, becomes strengthened. The fluoride ion becomes incorporated into the hydroxyapatite crystalline structure to form a substance called fluorohydroxyapatite (FAP), which is significantly more resistant to acid attack and subsequent decay. Moreover, the presence of fluoride in saliva helps demineralized teeth absorb calcium and phosphate ions so that damage can actually be reversed, a process known as remineralization. Last, fluoride ions affect the bacterial plaque directly by interfering with a step in carbohydrate metabolism. This not only reduces the amount of acid the bacteria can produce, it retards the reproduction of bacteria, resulting in slower-growing plaque.
So, the bottom line is that fluoride is a triple threat in the fight against tooth decay, a veritable hat trick of protection. In fact, the Centers for Disease Control (CDC) has recognized water fluoridation as one of the top 10 public health achievements of the 20th century, right up there with vaccinations, birth control, and figuring out that smoking is not that good for you.
What’s the catch?
There’s a catch. There’s always a catch. Over the 100 years or so that fluoride has been investigated by dental researchers, it has been recognized that too much fluoride can have a negative effect on the teeth, and in extreme instances, bones.
The most common adverse effect of an excess of fluoride is dental fluorosis. During tooth development in children (essentially from gestation until age 8 or so), fluoride is incorporated into the enamel as it forms. Usually this is a good thing, as it strengthens the tooth as described above; however, if too much fluoride is present, it can disrupt the formation of enamel, resulting in cosmetic blemishes on the surface of some or all of the teeth. This can start with mild fluorosis, in which small, almost imperceptible white spots are found on a single or a few teeth. The spectrum then continues to moderate fluorosis (in which more teeth are involved and are more apparent), up to severe fluorosis, where the tooth becomes mottled and the stains are brown and quite unaesthetic. Severe fluorosis actually increases the risk of decay.
There is also a condition known as skeletal fluorosis, in which excessive environmental fluoride can become incorporated in the bones, resulting in pain, limited movement, and disfiguration. It must be emphasized that skeletal and severe fluorosis of the teeth do not occur as a result of any sort of community water fluoridation, or because of fluoride in toothpastes or professional fluoride treatments. They occur in areas with naturally occurring fluoride levels far in excess of what is safe, and are rare in the United States. In these areas, a defluoridation process must be undertaken to return the water concentration of fluoride to safe and optimal levels.
So what is a safe and optimal level of fluoride?
Great question! I’m glad you asked.
For decades the optimal level of fluoride in drinking water fell in the range between 0.7 parts per million (ppm) and 1.2 ppm, according to the American Dental Association (ADA). This has been adjusted according to region and was affected by temperature (less fluoride in hotter areas), water hardness, and other factors. But trends in water intake, and significant increases in bottled beverage consumption, have led to a recent recommendation to decrease fluoride levels in community water supplies to 0.7 ppm across the board.
How much water people drink these days depends less on regional temperature variations, and the intake of bottled beverages that contain fluoride has increased dramatically. If a product is made with fluoridated water, it’s no different than drinking fluoridated water from your tap. So in many areas without fluoride in the community water, more kids are getting some in other ways and this has equalized the relative risk somewhat when comparing communities. If not taken into account, this might make the benefit of a community water fluoridation program seem less impressive.
Not all ingested fluoride comes in the form of water or water based products. There is also fluoride-containing toothpaste, and then supplement drops that have historically been used in children living in areas with low levels in the drinking water. In an individual kid under the age of 8 years, it is recommended that the daily intake of fluoride be in the 0.05 to 0.07 mg/kg. That seems to be the sweet spot between too much fluorosis and too many cavities. Research has shown that these levels are extremely safe, minimize any untoward side effects such as fluorosis, and maximize the protective benefits of fluoride in tooth enamel.
Fluoride drops have gone out of favor for the most part. They require a prescription, are more expensive than fluoride-containing toothpastes and don’t provide the benefit of topical fluoride once teeth have erupted. They also increase the likelihood of developing fluorosis. In many countries, including the United States, fluoride toothpaste is recommended in young children, although how young it should be initiated has been debated.
Current recommendations in the US are to begin using a fluoride toothpaste to brush with the first tooth in high risk children, and to start at age 2 years when the risk of caries is low. Most experts recommend an amount equal to a grain of rice in young children with an increase to a pea sized amount from 2 years on with each brushing. In reality, starting all children in infancy would be fine considering that the amount of fluoride in a smear the size of a grain of rice would be below the level that would cause fluorosis even if completely swallowed twice a day.
Another recommendation, and one which I’ve found surprises many people, is to not have children rinse after brushing. But it makes perfect sense once explained. Young children don’t know how to rinse and spit anyway, so will actually swallow more of the toothpaste if an attempt is made. And when a child is old enough to do so, the act nullifies the benefit of having topical fluoride in the first place. If you must rinse, it is best to use a fluoride containing product, but many of these contain less than what is in a pea sized amount of toothpaste so the fluoride will still be diluted.
Does it really work?
The American Academy of Pediatric Dentistry published their Guideline on Fluoride Therapy, an excellent document summarizing the current research and recommendations on fluoride use. Their conclusions are as follows:
1. There is confirmation from evidence-based reviews that fluoride use for the prevention and control of caries is both safe and highly effective in reducing dental caries prevalence.
2. There is evidence from randomized clinical trials and evidence-based reviews that fluoride dietary supplements are effective in reducing dental caries and should be considered for children at caries risk who drink fluoride-deficient (less than 0.6 ppm) water.
3. There is evidence from randomized controlled trials and meta-analyses that professionally applied topical fluoride treatments as five percent NaFV or 1.23 percent F gel preparations are efficacious in reducing caries in children at caries risk.
4. There is evidence from meta-analyses that fluoridated toothpaste is effective in reducing dental caries in children with the effect increased in children with higher baseline level of caries, higher concentration of fluoride in the toothpaste, greater frequency in use, and supervision.
5. There is evidence from randomized clinical trials that 0.2 percent NaF mouthrinse and 1.1 percentNaF brush-on gels/pastes also are effective in reducing dental caries in children.
The fluoride controversy
Despite its 50+ years of study, and positive track record of proven benefits, there remains a strong anti-fluoride sentiment in many people. Won’t go into it too much here, as Steve Novella wrote an excellent article on the subject; however, suffice it to say that there is a small but active movement in the US and worldwide to put forth their agenda of the evils of fluoride. Evidently, Big Fluoride is attempting to sap and impurify our precious bodily fluids.
Their concerns primarily come down to four claims, all of which are unfounded:
1. Fluoride is a potent toxin. It’s even on the warning labels on toothpaste to call poison control if ingested while brushing!
2. Adding fluoride to community water sources amounts to forcing a medication on the public!
3. Individual choice is not taken into account. People who want it can just take a supplement!
4. Adding fluoride to community water leads to a variety of ill health effects, including lowering IQ, broken bones, joint problems, dementia and cancer!
Fluoride is a naturally-occurring substance in water everywhere, often at levels much higher than what is recommended in community programs. And it isn’t unique among many beneficial substances in the fact that excessive amounts can be harmful. But to compare the adverse effects of fluoride to these other substances, many of which have no safe level of consumption, is absurd. The safety data is abundantly clear. There is no credible evidence to suggest that fluoride lowers IQ, causes intellectual impairment, or increases the incidence of any cancer. The benefit far outweighs the risk of fluorosis.
Fluoride also isn’t being used as a medication to treat a disease but as a means of prevention on a population level. There is little difference between putting fluoride in the water and folic acid in bread. And yes, there is even potential toxicity from too much of that too. Relying on people who want to take fluoride to do so would be a disaster. Many people would be unable to obtain it and it doesn’t work as well as topical fluoride once the teeth have erupted.
What can non-dental health care providers do? (Jones)
I grew up in Baton Rouge, the capital of Louisiana and home of the LSU Fighting Tigers. I don’t live there anymore but I’m proud to call the state my home. I’m also very thankful for the existence of Mississippi and Arkansas, bordering states which do a great job preventing us from being the worst state in the union when it comes to health. Louisiana is behind in a number of parameters, not the least of which is the overall state of pediatric oral health. Oral health in general is abysmal in the Sportsman’s Paradise. An assessment by the Louisiana Department of Health in 2010 revealed that we met essentially none of the goals set out by the CDC’s Healthy People 2010 objectives for improving oral health.
Focusing on pediatric concerns, the numbers really do look bad. For instance, a full two thirds of third graders in Louisiana have had dental decay, with a little over 40% being untreated. Both of these issues are more than 10% more prevalent compared to the national average. This jibes with my personal experience practicing medicine in Baton Rouge for four years before my recent move to the Northeast. There are a lot of rotten teeth in Baton Rouge children, because Baton Rouge has yet to develop a community program to bring fluoride levels in drinking water up to the recommended amount. That and roughly 70% of the children are on Medicaid.
Pediatric dentists have several fluoride-containing options to address cavity prevention and treatment in individual patients. There are foams, gels, rinses and toothpastes containing higher amounts of fluoride than the OTC variety. Historically non-dentist providers did their best counseling parents and children on good oral hygiene and trying to make referrals. Now, in places like Baton Rouge and Houston, where a majority of children have dental caries and access to a pediatric dentist is spotty at best, some offices are beginning to apply fluoride varnishes in high risk kids.
Fluoride varnish is highly concentrated and applied like paint with a special brush. The coating releases fluoride when plaque is present and an acidic environment begins to develop. There is very good data showing this to be highly effective in children of any age. All they need is a tooth and no special preparation is necessary. It is also very easy to apply, doesn’t taste bad, is portable and well-tolerated. So it is perfect for use in clinics, even schools perhaps. Insurance, even Medicaid, will pay non-dentists for the application in many, but not all states. Hopefully this will change.
Fluoride varnish is technically off-label at this time when used to prevent caries, but is approved for use as a desensitizing agent and cavity lining. But it has been used effectively in many other countries for years. And there is good evidence in support of the current recommendations to apply the varnish at least twice yearly in high risk children. Of note, in England varnish is recommended twice yearly in every child, and three to four times per hear in those at high risk. So varnish works, but is it cost effective? There is the rub.
From available data, it does not appear that the application of fluoride varnish is cost effective if done in every child. This is unfortunate because even low risk children receiving optimal daily fluoride exposure still can get cavities, and varnish is extremely safe. But when an appropriate risk stratification is performed, and varnish applied to only those who are at high risk for caries, it very likely would be cost effective. There isn’t data to support that assumption that I could find at this time, however.
Another intervention, this time at the community level, is the implementation of classroom-based toothbrushing programs. There is actually very good evidence from other countries that this is effective, but none in the US so far. Supervised brushing is part of our Head Start programs by the way.
Conclusion: Tooth decay is not good, fluoride is
Tooth decay is extremely common and much more than a simply nuisance. There are significant possible downstream effects. All children are at risk for developing caries, but some are at high risk for a variety of reasons, many of which are likely genetic. Having someone assign risk early in life, when true primary prevention is a possibility, is ideal and the non-dentist pediatric health care professional is well suited to do just that.
In a perfect world, every kid would see a pediatric dentist around their first birthday, or earlier if they are high risk, but there are huge gaps in access. This is particularly a problem in children living below the federal poverty line. Pediatricians are great at educating parents on how to improve oral hygiene but that isn’t always enough. The application of fluoride varnish in the clinic is a great possible intervention in high risk kids, although it is unclear if it is a cost effective one. At the community level, supervised brushing with fluoride containing toothpaste in the classroom is almost certainly another great means of decreasing rates of tooth decay.
Finally, don’t be afraid of fluoride. It is one of the best public health measures every devised and is extremely safe. Despite the vocal minority of anti-fluoridation folks, and numerous websites touting all manner of bogus adverse effects, there is no evidence to support fluoride as a cause of cognitive impairment, dementia, or cancer.