Dental surface restorations composed of dental amalgam, a mixture of mercury, silver, tin and other metals, significantly contribute to prolonged mercury levels in the body, according to new research from the University of Georgia’s department of environmental health science in the College of Public Health.
[Photo: Dr. Xiaozhong “John” Yu (left) and Dr. Lei Yin]
This research, which analyzed data from nearly 15,000 individuals, is the first to demonstrate a relationship between dental fillings and mercury exposure in a nationally representative population. The results were published online last week and will be available in the print edition of the journal Ecotoxicology and Environmental Safety in December.
“Tooth decay is one of the most prevalent chronic diseases,” said Dr. Lei Yin, a scientist in the department of environmental health science and the study’s lead author. “I think a majority of people have experienced dental fillings, but the kind of materials the dentist uses isn’t something that’s really discussed.”
Mercury exposure from dental fillings is not a new concern, but previous studies were inconsistent and limited, according to Dr. Xiaozhong “John” Yu, assistant professor of environmental health science and co-author of the study.
“This study is trying to provide the most accurate levels of exposure, which will form the scientific basis to make future risk assessment,” Dr. Yu said, adding that the study was the first to also control for age, education, ethnicity, race, gender, smoking and seafood consumption, which is a known contributor to mercury levels in the body.
The researchers further analyzed exposure by specific types of mercury and found a significant increase in methyl mercury, the most toxic form of mercury, related to dental fillings. Dr. Yu said this result suggests the human gut microbiota, a collection of microorganisms living in the intestines, may transform different types of mercury.
The results show that individuals with more than eight fillings had about 150 percent more mercury in their blood than those with none. The average American has three dental fillings, while 25 percent of the population has 11 or more fillings.
The study also looked at dental composite resins, a mercury-free alternative for dental fillings that can release small amounts of bisphenol A, or BPA, which may cause developmental or reproductive damage. The results found no association between dental fillings and urinary BPA, but further research is needed to understand BPA exposure from resin-based materials.
Read the entire article at: https://www.publichealth.uga.edu/ehs/news/dental-fillings-raise-levels-mercury-body-uga-study-says