(NaturalNews) Researchers have found a link between dental fillings made using bisphenol A, otherwise known as BPA, and behavior and emotional problems in children.
Scientists from New England Research Institutes in Watertown, Mass., say the effects generally show up a few years later and they were generally small but were nonetheless measurable.
The study's lead researcher was quick to note that her team did not measure levels of BPA in particular, and did not know if any other chemicals were possibly leaking from the fillings.
"It's a controversial topic in dental research, how much really does leach (from fillings)... and whether or not that would have an effect," said study lead Nancy Maserejian. "It's generally assumed that the amounts leached are tiny."
Maserejian went onto say that fillings made using the substance are starting to become more popular, in part because they are the same color as teeth - as opposed to earlier, silver-colored amalgam fillings, Reuters reported.
FDA wouldn't ban chemical's use in food packaging
According to the Web site "Facts About BPA," the substance is "the key component used to make epoxy resins and polycarbonate plastic, which are used to make consumer goods that make our lives safer and more convenient."
In addition, "BPA helps to make epoxy resins durable and to make clear polycarbonate plastic strong, lightweight and resistant to heat and shattering," the site noted.
Other reports described BPA as a chemical substance that is also found in some food packaging and canned goods. A 2011 study linked prenatal exposure to BPA with hyperactivity and anxiety in girls specifically, though overall its effects are not clear.
In March, the Food and Drug Administration announced it had rejected a petition from the Natural Resources Defense Council (NRDC) asking the agency to ban BPA in food-contact materials.
"The Food and Drug Administration's assessment is that the scientific evidence at this time does not suggest that the very low levels of human exposure to BPA through the diet are unsafe," the agency said on its Web site.
For the tooth study, Maserejian and her team examined data on 534 children, ages six to ten, who had cavities and were then randomly chosen to receive amalgam fillings or one of two different so-called composite fillings. BPA was used in the manufacturing of one of those composite fillings.
Five years later, parents and their children answered a number of questions regarding depression and anxiety, including attitudes at school and behavior overall.
Differences in behavior barely noticeable
The team found that kids who had multiple fillings containing BPA, and who'd had those fillings for quite a while - regularly posted scores of two to six points worse on a 100-point behavioral measurement scale than those children with no such fillings or who'd only had one for a short time.
The study found that behavioral problems were especially frequent among children who had those fillings on chewing surfaces, according to the team's report in the journal Pediatrics. The findings are consistent with the assumption that some fillings could break down over time and thus leach chemicals that could cause harm.
Maserjian said it could be the fillings tested contained residual BPA used in making them, though it isn't supposed to be a main ingredient. But whether or not that's true, and whether the small amounts of chemicals could have affected brain development, is all hypothetical.
"We didn't measure BPA, and we don't know whether BPA was in (the fillings)," she told Reuters. "There are other chemicals used in these composites, and BPA isn't directly used in them. We don't really know what the health effects of these other chemicals are."
To find out, she added, more research will be needed, but in the meantime, she advised parents not to worry too much just yet. That's largely because the difference in behavior between kids with the different types of fillings was small enough "they would not be noticeable for most children."