New research from the French National Institute of Health and Medical Research (INSERM) in Paris has found that molar incisor hypomineralisation (MIH), a tooth enamel defect found in children, may result from exposure to the industrial chemical bisphenol A (BPA). This was shown by exposing rats to the chemical from foetal life to 30 days post-birth, and observing that BPA caused enamel defects similar to MIH in humans, especially in male rats.
BPA is an endocrine disruptor, or hormone-altering chemical, that has been linked to numerous adverse health effects in humans. It appears in many plastic and resin household products and food containers, including until recently baby bottles, sippy cups and infant formula packages.
Recent published data show that MIH affects up to 18 percent of children ages 6 to 9 years. Although the cause is unclear, it appears to have an environmental origin, according to the study authors.
Commenting on the value of the study, researcher Sylvie Babajko said: “Human enamel defects may be used as an early marker of exposure to BPA and similar-acting endocrine disruptors”.
In part 2 of the study, the investigators cultured and looked at rat ameloblast cells, which are present only during the formation of tooth enamel, called amelogenesis. This cell-based experiment showed that sex hormones target and influence dental epithelial cells. This finding, said Babajko, suggests possible sexual differences in enamel quality.
Hailing the study a success, Babajko concluded: “Our study shows, for the first time, that BPA affects dental cells, and subsequently enamel synthesis, using similar target molecules as those present in other organs.”