Bisphenol A (BPA) is an organic compound that is used in plastic containers, baby bottles, pacifiers, and water jugs. It is also used in some dental fillings for restoration of tooth cavities. In recent times, bisphenol A has been surrounded by controversy over the possible health hazards that it may exert when chronic low level exposure occurs in humans. BPA can have weak hormonal effects, and animal studies have shown that it can cause changes in the developing genitor-urinary tract, effect prostate and breast tissue, and produce aggression and hyperactivity. In Canada and the European Union, bisphenol A is considered a toxic compound and its use is banned in baby bottles. The United States Food and Drug Administration has also recently banned the use of BPA in baby bottles and sippy cups. Despite this, BPA is still used in other products that may be harmful to humans.
Researchers, lead by Dr. Nancy Maserejian, have found that children who are exposed to bisphenol A in dental fillings have higher rates of behavioral problems when compared to children with no exposure to the compound. The results of their research were published online in the journal Pediatrics. The researchers analyzed data from the New England Children’s Amalgam Trial, and included 534 children aged 6 to 10 years of age. The study participants were followed for a five year period and had neuropsychiatric assessments performed to determine levels of aggression, mood disturbances, school performance, and interpersonal relationships. It was found that children with higher levels of exposure to bisphenol A based composite fillings had lower scores on neuropsychiatric tests, reflecting a negative influence of the compound on behavior. This association was strongest for BPA composite fillings that were placed in the back of the mouth, where increased wear and tear could cause more release of the compound.
The authors wrote, “These findings indicate that exposure to [bisphenol A]-based dental composite resins may impair psychosocial health in children. With increasing level and duration of exposure to [bisphenol A]-based composite over 5 years of follow-up, children reported more anxiety, depression, social stress, and interpersonal relation problems… Our finding that cumulative exposure to composite on posterior-occlusal (chewing) surfaces was most strongly associated with poorer psychosocial outcomes supports the hypothesis that long-term release of resin components caused these associations”. In addition, the authors commented “Longitudinal trials are needed to examine modern-day resin-based dental materials for the long-term release of their components and health effects”.
Future studies will need to determine if it is bisphenol A in the dental fillings that is causing the observed association with behavioral problems in children. In addition, the exact mechanism for the observed effect will need to be elucidated. With all the health concerns regarding bisphenol A, health regulatory agencies will need to more closely examine the safety of this compound. It will also need to be determined whether it should be completely banned from food containers. Several other countries have already done so, and it may be time for the United States to do so as well.
Nancy N. Maserejian et al. “Dental Composite Restorations and Psychosocial Function in Children” Pediatrics published online July 16, 2012 doi: 10.1542/peds.2011-3374
Sabrina Tavernise “F.D.A. Bans BPA From Baby Bottles and Sippy Cups” New York Times July 17, 2012