FRIDAY, June 6, (News Locale) - Ever since dental amalgam or "silver" fillings gained popularity, there has been widespread concern about the effects of mercury on human health. Now the US Food and Drug Administration has officially admitted that mercury in dental fillings may be harmful to the health of pregnant women, children and fetuses. 

"Dental amalgams contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses," the agency said on its website. "FDA’s rulemaking will examine evidence concerning whether release of mercury vapor can cause health problems, including neurological disorders, in children and fetuses."

Below are few questions and answers about dental amalgam and the FDA's latest ruling

What is dental amalgam/silver filling?
Dental amalgam is one of the oldest materials used in dentistry for filling cavities in teeth. Since the last 150 years, dentists have been carrying out routine restorative work using amalgam. Although newer materials have broken ground, it is widely acknowledged that amalgam happens to be the best material for dental fillings.

Chemically amalgam is composed of equal parts of elemental liquid mercury and an alloy powder that contains (in descending order) silver, tin, copper, and sometimes smaller amounts of zinc, palladium (or indium.)

Why is there a hue and cry over the use of amalgam?
The problem centers over the use of mercury, which is a known human neurotoxin. Mercury is known to cause of chronic illnesses, autoimmune disorders, neurodegenerative diseases, birth defects, and mental disorders.

In fact mercury is implicated in the development of autism as well although no conclusive proof exists.

What has the FDA done to regulate the use of mercury in dental fillings?
In 2002, the Food and Drug Administration said there was no valid scientific evidence to prove that amalgams cause harm to patients with dental restorations. In the same year the FDA proposed to dental amalgam as a class II device with special controls. 

Do studies support the theory of mercury from dental fillings causing health issues?
In 2005 a report by the Freiburg University Institute for Environmental Medicine said there was evidence that removing dental fillings containing mercury resulted in the resolution of chronic complaints by a number of patients in clinical trials.

It added that low-dose mercury exposure was linked to Alzheimer's disease or multiple sclerosis, neurobehavioral changes, autoimmunity, oxidative stress and autism.

However a 2004 review by the Life Sciences Research Office did not find any evidence to show that silver fillings caused any neurological issues.

What prompted the FDA to issue a new statement?
A lawsuit by consumer groups and individuals concerned about mercury exposure forced the FDA to review existing literature on the subject.

What is the FDA advising?
"Pregnant women and persons who may have a health condition that makes them more sensitive to mercury exposure, including individuals with existing high levels of mercury bioburden, should not avoid seeking dental care, but should discuss options with their health practitioner," the FDA has said. If you are concerned about the possible health effects of amalgam fillings, you should talk with your qualified health care practitioner.

How has the American Dental Association reacted to FDA's advisory?
"People depend on the FDA and other government health agencies to help protect their health. It's critically important that public health recommendations are based on sound scientific evidence," states ADA President Mark J. Feldman, DMD. "The ADA will continue to advocate for the best oral health of the public as part of the FDA regulatory process."

What is the FDA going to do now?
FDA reopened the comment period for classifying dental amalgam as a class II device with special controls on April 28, 2008. The comment period will be open until July 28, 2008. After reviewing all comments, FDA intends to issue a final rule classifying dental amalgam.

What should consumers who have amalgam fillings do?
FDA does not recommend that you have your amalgam fillings removed. FDA is engaged in a rulemaking that may lead to revised labeling. It is also reviewing evidence about safe use, particularly in sensitive subpopulations.

The ADA believes that dental amalgam remains a safe, affordable and durable cavity filling choice for dental patients.

For consumers, especially pregnant women and children, it may make sense to go for amalgam alternatives in discussion with their dentist.