The standard dental amalgam used to fill cavities in children’s teeth is comprised of 50% mercury.  It is estimated that 70 million fillings using mercury amalgam are performed yearly in the U.S.  Because mercury is a neurotoxin, there have been concerns for years that people with mercury fillings may be exposed to a health hazard.

Recently, two large studies examined whether using mercury fillings is cause for concern.  One of the studies was a randomized clinical study of 534 children followed for 5 years that looked at kidney function and neuropsychological function and kidney function.  Researchers assessed the children for IQ, memory, kidney function, and visuomotor ability before their teeth were filled and again after five years.  The control group used a filling made without mercury while the experimental group used a filling made with mercury.  The researchers found no difference between the two groups and concluded that “There is no reason to discontinue use of mercury amalgam as the standard of care for caries in posterior teeth.”

A similar study was conducted in Portugal on 507 children randomly assigned to a treatment group that found similar results.  These children were 8-10 years old and followed for 7 years and were assessed for memory, attention and concentration, nerve conduction, and motor and visuomotor domains before receiving fillings and again after seven years.  No difference was found between the two groups.

It should be noted that further research is still needed to demonstrate safety over longer periods of time.  However, currently there does not appear to be a measurable risk from using the standard dental fillings.

Sources:  Bellinger DC, et al. (April, 2006).  Neuropsychological and Renal Effects of Dental Amalgam in Children. JAMA, 295:1775-83; DeRouen TA, et al. (April, 2006). Neurobehavioral Effects of Dental Amalgam in Children. JAMA, 295:1784-92.