2. Is Mercury Released from Fillings? The Patient Asks "Does the mercury come out of my fillings when I eat or chew gum?" The ADA Answers "Recent advances in both equipment and measurement techniques have allowed researchers to detect extremely low levels of mercury vapor in patients' breath after they have chewed vigorously. Very small quantities of this mercury vapor are absorbed by the body instead of being exhaled. But no evidence exists that associate this minute amount of mercury vapor with any toxic effects." IAOMT Response The ADA answer is false. Published experimental evidence as early as 1926 has demonstrated that mercury is not locked in, but is released from fillings.(16) More recent research has shown that both chewing and tooth brushing release mercury vapor into the human oral cavity.17, 18, 19 Recent advances in both equipment and measurement technique have allowed researchers to find intra-oral mercury levels thirty to one hundred times higher that the United States Environmental Protection Agency's (USEPA) maximum allowable concentration for air quality (0.3 part per million). 20, 21, 22, 23, 24, 25, 26 Toxicology authorities maintain that there is no threshold level of mercury exposure which can be considered totally harmless. 27 28 Dental fillings release mercury. The mercury release dramatically increases with pressure or heat stimulation to the fillings and does not return to baseline for more than 90 minutes. 29, 30 This continual release of mercury will inevitably result in measurable exposure from the 17,000 breaths that a person inhales daily. Once this mercury is inhaled 74% to 100% of the mercury is absorbed from the lung into the blood stream and distributed throughout the body.31 Personal habits such as chewing gum, grinding teeth and mouth breathing will greatly increase an individuals daily dose exposure to dental amalgam mercury. The 1/2 life for mercury in humans is approximately 70 days. Thus, small multiple daily doses of mercury will result in a significant accumulation over time. The critical issues are the potential for exposure to the developing fetus and mercury accumulation in children because of their low body weight. To study these possibilities Vimy et al. (1990) designed an elegant animal experiment utilizing sheep and radioactively tagged mercury 203. Twelve occlusal amalgams were placed in the molars of pregnant sheep. The mothers femoral vein, the placental sack and the femoral vein of the fetus were cannulated. 32, 33 Radioactivity measurements determined the presence and quantity of mercury from the dental amalgam fillings in the various body tissues of both the mother and fetuses. The experiment is specific for mercury from fillings, since radioactive mercury is not a naturally occuring substance in the environment. The design of this experiment eliminates the issue of mercury source. Within 3 days after amalgam placement mercury was found in the maternal blood, amniotic fluid, fetal blood, and maternal urine and feces. By 16 days after amalgam placement the maternal mercury levels were highest in the kidney, liver, G.I. tract, and thyroid. The mercury levels in the fetus were highest in the pituitary, liver, kidney, and placental cotyledon. At 33 days after amalgam placement (birthtime), most fetal tissues had higher levels of mercury than the maternal tissues. Specifically, the fetal liver, epiphysial bone, bile, bone marrow, blood, and brain. During lactation there was 8 times more mercury in the milk than maternal blood serum. This resulted in an increase in mercury exposure to the neonate. Seventy-three days after amalgam placement, mercury levels in the maternal kidneys, liver, parotid glands, pancreas, pituitary glands, urine, bile, brain, and thyroid were still rising slowly. The researchers concluded that mercury vapor released from dental amalgam fillings is readily absorbed in lung, gastrointestinal tract and jaw bone and progressively accumulates in maternal and fetal tissues with exposure duration. Neonatal mercury exposure from this dental material occurs via milk. They stated in their conclusions that, "our laboratory findings in this investigation are at variance with the anecdotal opinion of the dental profession, which claims that amalgam tooth fillings are safe." The ADA Answers "Recent advances in both equipment and measurement techniques have allowed researchers to detect extremely low levels of mercury vapor in patients' breath after they have chewed vigorously. Very small quantities of this mercury vapor are absorbed by the body instead of being exhaled. But no evidence exists that associate this minute amount of mercury vapor with any toxic effects."