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By Jennifer Garvin

Two studies in the April 19 issue of the Journal of the American Medical Association conclude that children with dental amalgam fillings do not experience adverse effects related to neurobehavioral, neuropsychological (IQ) and kidney function, reinforcing the ADA's longstanding position on the safety of dental amalgam.

The ADA reports that both independent studies "reinforce the substantial body of peer-reviewed scientific literature that supports the safety of dental amalgam."

	Timothy DeRouen: Studies are the "first bit of objective evidence."

According to JAMA, both articles, "Neurobehavioral Effects of Dental Amalgam in Children" and "Neuropsychological and Renal Effects of Dental Amalgam in Children," are the first randomized controlled trials comparing the health effects in children treated with amalgam fillings with those treated with composite resins. The former was conducted in Lisbon, Portugal, and involved 508 children, ages 8 to 10, who were randomly assigned amalgam or composite fillings. The latter took place in Boston and Farmingham, Maine, and comprised 534 children, ages 6 to 10, who also were randomly picked to receive amalgam or composites. Both studies were funded by the National Institute of Dental and Craniofacial Research and were made up of children who had no previous restorations.

"It's the first bit of objective evidence other than heated opinion and observational studies," said Timothy DeRouen, Ph.D., lead author of the Lisbon study and executive associate dean for research and academic affairs at the University of Washington School of Dentistry.

In a press release sent to media outlets across the United States, the ADA says, "These studies support existing scientific understanding that the minute amount of mercury released by amalgams during eating and drinking does not affect health adversely." The Association goes on to reinforce that "both studies support the continued use of dental amalgam as a treatment option."

The studies conclude that there were no clinical adverse effects on neurological and kidney function in children with dental amalgam fillings and health effects of amalgam restorations should not be an issue when choosing a restorative material. The studies also noted mercury in urine increased in children exposed to amalgam restorations, but remained within the range of normal background levels.

Good vs. bad science: ADA Executive Director James Bramson (left) gives his "Facing the Future" report to the Council on Scientific Affairs during its April 20 meeting. Dr. Bramson praised the council by telling them, "it's a huge responsibility to educate our members on what's good science." Dr. Douglas Dederich, CSA vice-chair, is shown at right.

"These studies actually sacrificed some statistical power to undergo a mid-trial analysis of data by their respective data safety monitoring boards," said Dr. Fred Eichmiller, director of the ADA Foundation's Paffenbarger Research Center. "The monitoring board broke the randomization code and did a complete statistical analysis of the results. This is something that is very much over and above what would be done in most clinical trials and was done to specifically address the possibility of some adverse response occurring in these children. The mid-trial analysis did not find any adverse response, and the trials went on to completion.  The findings were definitive enough that they still had excellent power in the statistics, even after sacrificing some with this mid-trial analysis." 

The April 19 JAMA also includes a "misleading" editorial by child psychiatrist Herbert L. Needleman, M.D., that "draws conclusions supported primarily by his own speculation and dramatically at odds with the published science," the ADA says.

"It is important to note that his opinion contradicts much of the hard science presented in the two published studies, as well as a huge body of existing, peer-reviewed literature," the ADA said in a statement. "The public deserves health care treatment which is based on the weight of scientific evidence, not speculative opinion. The ADA is committed to promoting sound health care policy based on science, not conjecture."

The ADA's press release to the public says, "The bottom line for consumers: Dental amalgam remains among several safe, effective options for treating dental decay."

For comprehensive information about restorations and all other aspects of dental care and oral health, visit www.ada.org/prof/resources/topics/amalgam.asp.

Additionally, members are advised to direct patients seeking more information to www.ada.org/goto/fillings.