While most fillings are successful and long-lasting, sometimes they do fail. And according to research published last month in the European Journal of Paediatric Dentistry, mercury amalgam fillings fail a little less often than composite (and a lot less often than glass ionomer) – at least among the 300 children’s teeth that were studied.
Not that this is reason to give three cheers for mercury and call it a day.
As we’ve noted before, there is a wealth of scientific research demonstrating the harm that dental mercury can do. As one recent research review succinctly put it,
the preponderance of evidence suggests that Hg exposure from dental amalgams may cause or contribute to many chronic conditions.
The concern is even greater when it comes to children. Their bodies and brains are still developing, after all, making them even more vulnerable to mercury’s effects. Even the FDA, trusting in amalgam’s safety, only deems it safe for adults and children older than 6.
After all, they explain, “The developing neurological systems in fetuses and young children may be more sensitive to the neurotoxic effects of mercury vapor.” Mercury is a potent neurotoxin.
As for older kids, mercury amalgam supporters often cite the 2006 Children’s Amalgam Trials as evidence of their safety. However, the IAOMT and other mercury and toxicology experts quickly recognized the severe flaws in those trials. Here, Dr. Boyd Haley summarizes those problems and how the findings don’t jibe with what we know about mercury:
“These studies,” remarks the IAOMT, “were poorly designed and tell us one thing of good value – that children with amalgams most likely slowly lose their ability to excrete mercury after about two years of amalgam exposure.”
Though it downplays amalgam’s risk, a 2010 study in Current Problems in Pediatric and Adolescent Health Care reports that the long-term consequences of mercury exposure may affect almost all part of a child’s development:
Because important systems are still differentiating and growing, children have unique susceptibilities not seen in adults—and critical time windows for those susceptibilities. The critical times are preconception, gestation, and postnatal. More than 1 system can be susceptible and different pathology may occur depending on the dose and timing of exposure. The fetus and infant are especially vulnerable to mercury exposures. Of special interest is the development of the central nervous system. With the formation of neuronal cells and the subsequent stages of development, the central nervous system is created. Damage of the nervous system caused by mercury is likely to be permanent. Neurotoxic effects can result from prenatal or early postnatal exposure.
Of course, as is true for adults, not all children will respond to mercury amalgam in the same way. A 2014 study in Neurotoxicology, for instance, found genetic factors at play.
Among boys, significant modification of Hg [mercury] effects on neurobehavioral outcomes over a broad range of neurologic domains was observed with variant genotypes for 4 of 13 genes evaluated.
In contrast, significant modification of Hg effects on neurobehavioral functions among girls with the same genotypes was substantially more limited. These observations suggest increased susceptibility to the adverse neurobehavioral effects of Hg among children, particularly boys, with genetic variants that are relatively common to the general human population.
Even if some children are more susceptible than others, all children may eventually display symptoms of toxicity if exposed to too much mercury. For amalgam is far from the only source. Some contend that environmental factors play an even bigger role than mercury fillings – in which case, it can only compound the problems of children with a mouthful of amalgam.
Obviously, preventing caries and the need for any fillings at all is the way to go, but the fact remains that some children will need them to restore their oral health. Life happens. But you can make sure you rely on a mercury-free, mercury-safe dentist who will ensure that only safe materials are used.
Fillings should be a fix, not a step towards a much bigger problem.
Image by jarmoluk
