Mercury Exposure Risks Posed By Dental Fillings, Researchers Warn

The findings of new research raise serious health concerns about the safety of certain dental fillings, indicating that exposure to mercury from a high number of amalgam fillings may cause toxic side effects. 

In a study published this month in the medical journal Ecotoxicology and Environmental Safety, researchers from the University of Georgia found that those with eight fillings or more had 150% more mercury in their blood than those who have less or no fillings, and were at higher risk of side effects.

Researchers examined blood and urine samples of nearly 15,000 subjects, evaluating the association between dental surface restorations and levels of mercury in the blood, including inorganic mercury, methyl mercury, the most toxic type of mercury, and urinary Bisphenol A (BPA). The study focused on both mercury from amalgam fillings and BPA from composite resin fillings.

Mercury, silver, copper, and tin are frequently used in dental fillings. These metals can leach into the body and cause toxic side effects, health experts say.  Mercury is a known toxicant and at high levels it can cause serious side effects to the brain, heart, kidneys, lungs and immune system.

In 2010, the FDA launched an investigation into the side effects of mercury dental fillings on human health. The review was spurred by many organizations that insisted the mercury caused widespread health problems, including neurological damage and Alzheimer’s disease. In 1991 the World Health Organization concluded the largest source of mercury for the general population comes from dental amalgams.

Participants involved in the study were divided into three groups, based on the number of fillings they had. Blood and urine samples were taken from three time periods from 2003 to 2012.

Researchers concluded that participants with eight or more fillings had 150% more mercury in their blood than those with no fillings. On average, American adults have three fillings each, but 25% of American adults have 11 or more fillings, significantly boosting their exposure to mercury and potential for toxicity.

Overall, participants with mercury fillings had higher than normal levels of the metal in their blood.

Conversely, researchers found no link between composite fillings and increased levels of urinary BPA. There was no significant increase in BPA among people with fillings in either period of the study.

Dentists consider amalgam fillings to be safe, and to have antibacterial qualities. They have an average lifespan of 30 to 40 years, so new research isn’t initiated to develop new compounds or types of filings that may be safer for the body.

Alternatives, like composite resins, have small levels of BPA in them and many health experts worry they may pose a risk that has not been discovered, as BPA is a known endocrine disruptor and can cause far reaching health side effects.

Studies have found links between BPA exposure and increased risk of obesity and diabetes, as well as exposure before birth to increased risk of breathing problems. Another study indicate even at low levels, BPA exposure may be more harmful to humans than scientists originally thought.

Researchers say more advanced research is necessary to understand the effects of BPA exposure from resin-based materials as well as side effects to the general population from mercury fillings.