Heavy metals found in dental work do not cause health problems, according to WebMD. The level of mercury that is present in dental fillings is too low to be detrimental to human health.
When cavities are removed, the teeth are filled with dental amalgams that may contain mercury and other heavy metals. At high enough levels, heavy metals are toxic to the body and cause damage to the brain and kidneys, WebMD says. Although there is little evidence that the heavy metal content of dental amalgam is harmful, there are alternatives, such as dental composite, that do not contain heavy metals, according to the American Dental Association.