I happened across a great article in the New York Times (readers of this blog may have come to the realization that I’m an avid reader of this publication) that sang the praises of the dental sealant. It still comes as a shock to me to hear of members of my own profession who still don’t place sealants on a routine basis. At our practice, most of our patients have sealants placed; the rare instances when we elect not to place them are for patients with extremely shallow grooves, easily cleaned teeth and a history of no cavities. Otherwise, we are HUGE believers in the value of sealants.
Consider this – most members of the Silent Generation, and even Boomers have a mouthful of fillings, crowns, implants, partial dentures and even full dentures. One of the unheralded medical discoveries of the past century, was that of fluoride, and it’s role in the prevention of dental cavities. In fact the Centers for Disease Control and Prevention (CDC) named the fluoridation of drinking water as one of the Ten Great Public Health Achievements in the 20th Century. And its impact has been seen in the substantial decline in dental disease in both the USA and around the world. However, there are still pockets of resistance in certain population groups (ie. low income communities, individuals with poor access to dental care) where dental caries is still prevalent. Surveys by the CDC show that 21% of children between 6 and 11, and 58% of adolescents have had cavities. So there is still work to be done in decreasing caries especially among the younger members of our population.
That’s where sealants come in. Sealants are a plastic-like tooth colored coating which is easily applied, fills in all the grooves and pits of a tooth where food tends to stick, is cost effective, and has been shown in countless studies to prevent cavities. Where fluoride works well in preventing what’s known as smooth surface (parts of the teeth that are smooth such as in between teeth) caries, it is less effective for preventing caries in the pits and fissures of teeth. It is these areas that are found to disproportionately develop cavities in the teeth of adolescents. And that’s exactly where sealants do their anti-cavity work.
I won’t bore you with the numbers, but the takeaway from the Cochrane study (which looked at 34 well designed sealant studies involving 6000 plus children/adolescents) is that in a population of cavity-free children with a 40% chance of getting a cavity in the next two years without sealants, application of sealants would reduce the rate to just 6%. (For those interested in more scholarly evidence, click here.) Admittedly not zero, which is every dentist’s goal but pretty darn close.
If Evidence-based dentistry is the use of current scientific evidence to guide decision making in dentistry, one should clearly be a believer in the important role sealants play in reducing cavities.
What if you, as a parent who has a very young child with a cavity, is told that instead of a 30 minute long appointment consisting of the dreaded shot, drilling, and no small amount of drama, that we could very simply, in less than a minute paint a magic substance on your child’s cavity, and voila, cavity is taken care?
Well, what if we told you that such a substance has been used in Japan for the past 80 years, can apparently basically ‘freeze’ cavities in place eliminating the need for placing a filling, and that the cost of such treatment is fairly low. Sounds good doesn’t it?
That magic substance is Silver Diamine Fluoride (SDF). It is a colorless liquid consisting of 24-28% silver and 5% fluoride. The FDA recently approved this for use as a cavity varnish placed on enamel to reduce tooth sensitivity. Though it hasn’t been technically approved for use in the treatment of cavities, some dentists have started using SDF ‘off-label’ (which is allowed) for management of the aforementioned cavities.
As we alluded to in the introduction, the dentist simply dries the tooth with the cavity, swabs a small amount of the SDF liquid on the tooth, allows it to dry (1-2 minutes), and you’re done – the cavity is arrested (which means it kills the bacteria causing the cavity, hardens dentin, and promotes re-mineralization or hardening of the surrounding enamel).
Of course, as with any treatment option, there are some downsides to this treatment. The most significant is that any tooth treated with SDF will turn black in color. To be completely fair, only the cavity turns black, but when we say black, we mean BLACK. Not a slight discoloration, or graying. Black.
It also requires multiple applications for complete success, cannot be used in individuals who have silver allergies, can cause irritation to gum tissue, and has a slight metallic taste when first applied.
While SDF has been used for decades in not only Japan, but also Brazil, Peru, Australia, Thailand and a slew of other Asian countries, studies looking at its efficacy, and safety in the U.S. are limited. To date, there have only been 14 reputable studies on SDF; 7 of which have been completed, 5 that are recruiting, and 2 that have not yet begun recruiting.
Despite it’s drawbacks, there is probably a place for SDF in dentistry. Patients who are unable to tolerate extensive or any dental treatment such as the very young, very old, and/or medically compromised seem like candidates who would benefit from this very non invasive treatment. However, it needs to be understood, that this is not a cure for cavities – it is simply managing a disease process until such time that more definitive treatment (ie. filling, crown) can be completed. Furthermore, more research need to be done around issues of effectiveness, long term safety and treatment protocols.
(Click here for a recent New York Times article on this issue)