Studies evaluating health effects of dental amalgam fillings in children confirm safety

June 28, 2006

For the first time at a major international meeting, scientists are reporting the results of the first-ever randomized clinical trials to evaluate the safety of placing amalgam fillings, which contain mercury, in the teeth of children. The findings will be presented today during the 84th General Session of the International Association for Dental Research, convening at the Brisbane Convention & Exhibition Centre.

Both studies--one conducted in Europe, the other in the United States--independently reached the conclusion that children whose cavities were filled with dental amalgam had no adverse health effects. The findings included no detectable loss of intelligence, memory, coordination, concentration, nerve conduction, or kidney function during the 5-7 years the children were followed. The researchers looked for measurable signs of damage to the brain and kidneys, because previous studies with adults indicated that these organs might be especially sensitive to mercury.

The authors noted that children in both studies who received amalgam, informally known as "silver fillings", had slightly elevated levels of mercury in their urine. But after several years of analysis, they determined that the mercury levels remained low and did not correlate with any symptoms of mercury poisoning.

The two studies are: the New England study, which was undertaken in the urban Boston (MA) area and rural Farmington (Maine), and the Portuguese study, conducted in Lisbon, Portugal. Each study enrolled over 500 children who had existing untreated decay in permanent posterior, or back, teeth, but no previously placed dental amalgam fillings. Each child was randomly assigned to receive either amalgam or composite resin (tooth-colored) fillings while participating in the research studies. All were evaluated for several years thereafter to determine if any health changes occurred, with emphases on IQ changes in the New England study and on memory, concentration, coordination, and nerve conduction measures in the Portuguese study.

The scientists noted that children in both groups were in great need of dental care. Among those in the amalgam group, children had, on average, 10.1 tooth surfaces treated upon entry into the study. By year seven of the study, they had received, on average, a total of 18.7 surface restorations. Each tooth has either four or five defined surface areas, totaling 128 surfaces in the 32 permanent teeth.
-end-
The studies were supported by the National Institute of Dental and Craniofacial Research (NIDCR), part of the U.S. National Institutes of Health.

This is a summary of two abstracts-- "Randomized Clinical Trial of Neurobehavioral Effects of Amalgam in Children", by T. DeRouen et al., of the University of Washington (Seattle, USA) and the Universidade de Lisboa (Lisbon, Portugal), and "Randomized Clinical Trial of Safety of Dental Amalgam in Children", by S. McKinlay et al., of the Harvard Medical School, New England Research Institutes, Sahlgrenska Academy (Sweden), Forsyth Institute, University of Rochester (NY, USA), and University of Maine (Farmington), to be presented at 1:00 p.m. on Wednesday, June 28, 2006, in the Room M3 of the Brisbane Convention & Exhibition Centre, during the 84th General Session of the International Association for Dental Research.

International & American Associations for Dental Research

Related Memory Articles from Brightsurf:

Memory of the Venus flytrap
In a study to be published in Nature Plants, a graduate student Mr.

Memory protein
When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.

Previously claimed memory boosting font 'Sans Forgetica' does not actually boost memory
It was previously claimed that the font Sans Forgetica could enhance people's memory for information, however researchers from the University of Warwick and the University of Waikato, New Zealand, have found after carrying out numerous experiments that the font does not enhance memory.

Memory boost with just one look
HRL Laboratories, LLC, researchers have published results showing that targeted transcranial electrical stimulation during slow-wave sleep can improve metamemories of specific episodes by 20% after only one viewing of the episode, compared to controls.

VR is not suited to visual memory?!
Toyohashi university of technology researcher and a research team at Tokyo Denki University have found that virtual reality (VR) may interfere with visual memory.

The genetic signature of memory
Despite their importance in memory, the human cortex and subcortex display a distinct collection of 'gene signatures.' The work recently published in eNeuro increases our understanding of how the brain creates memories and identifies potential genes for further investigation.

How long does memory last? For shape memory alloys, the longer the better
Scientists captured live action details of the phase transitions of shape memory alloys, giving them a better idea how to improve their properties for applications.

A NEAT discovery about memory
UAB researchers say over expression of NEAT1, an noncoding RNA, appears to diminish the ability of older brains to form memories.

Molecular memory can be used to increase the memory capacity of hard disks
Researchers at the University of Jyväskylä have taken part in an international British-Finnish-Chinese collaboration where the first molecule capable of remembering the direction of a magnetic above liquid nitrogen temperatures has been prepared and characterized.

Memory transferred between snails
Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro.

Read More: Memory News and Memory Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.