I wanted to say a few words on this topic… since it is one people ask me about often – and I found excellent articles in the CAND’s Vital Link Spring 2010. Thank you to Dr Gary Fortinsky and Dr Tawnya Ward. Here is a summary:
Chronic mercury exposure and toxicity can lead to organ damage of the central nervous system, glands, kidneys, liver, and fetus as it crosses both the blood-brain and placental barrier. I will not go into all the possible effects of mercury on the body, since there is too much information on this topic, however I wanted to bring to your attention the sources of mercury and specifically, how it relates to dental amalgams.
Mercury has two forms: organic (methyl, ethyl, and phenyl), and inorganic (elemental)
Methyl mercury is commonly found in contaminated fish and ethyl mercury is found in some vaccines, opthalmological solutions, skin-lightening creams, and some traditional/natural medicines (therefore it is very important to purchase good quality vitamins, supplements, or herbal formulas) (1).
Inorganic mercury is found in dental amalgams, foods, mercury products such as make-up, and from occupational exposure.
High-fructose corn syrup can have traces of inorganic mercury in order to adjust the pH via mercury grade sodium hydroxide. Membrane grade sodium hydroxide is a more suitable alternative. Citric acid and sodium benzoate contain inorganic mercury (2).
In dental amalgams, elemental mercury vapour off-gases to the lungs where it enters the blood-stream. 80% is absorbed via this route (3).
94% of organic methyl mercury is absorbed through the gastro-intestinal tract, while only 1% of inorganic mercury is absorbed.
Organic and inorganic mercury can be converted into each other in the gastrointestinal tract.
The amount of mercury released from dental amalgams increases after drinking hot liquids, chewing, or brushing teeth (3). However, the amount absorbed is highly debated. Some conditions that can be as a result from chronic low-dose mercury inhalation include heart palpitations, chest pains, inflammation of the oral mucosa, elevated blood pressure, increased salivation, decreased hemoglobin and hematocrit, tremors, and muscles pains.
Some dentists do not support removal of amalgams because mercury is released during removal. And, concurrently, the American Dental Association does not acknowledge the release of mercury from amalgams. The position of Health Canada states that amalgams do not pose a risk, however one large-scale study did demonstrate a significant exposure:
The Health Canada report entitled « Assessment of Mercury Exposure and Risks from Dental Amalgam » was prepared for the Medical Devices Bureau by Dr. Mark Richardson and released in November, 1995. It was the first comprehensive risk assessment in Canada of mercury exposure from dental amalgam.
This study made an estimate of the exposure of the Canadian population to mercury from amalgam, food, and the environment. The study did not include laboratory research or clinical investigations. It reviewed the international literature on the health effects of mercury and used sophisticated computer modelling techniques to calculate mercury exposure from amalgam. This calculated exposure was then used in standard risk assessment procedures to estimate a tolerable daily intake level (TDI) for mercury.
Using this model, the report estimated that for Canadians with amalgam-filled teeth, the average daily mercury exposure (the amount of mercury absorbed by the body) from all sources of mercury ranges from 3.3 µg for toddlers to 9.4 µg for adults aged 20 to 59. Estimates of exposure from amalgam alone ranged from 0.8 µg for toddlers to 3.4 µg for adults aged 20 to 59.
The Monte Carlo simulations indicated that amalgam contributes about 50% of the daily mercury exposure of the average Canadian. This makes amalgam the most significant single source of mercury exposure, compared to food, indoor and outdoor air, drinking water, and soil.
Health Canada Stakeholders concluded that adverse effects such as – tremors of the forearm as seen in industrial workers – is the endpoint measure for mercury exposure, and not tolerable daily intake. Here is the link for more information: http://www.hc-sc.gc.ca/dhp-mps/md-im/applic-demande/pubs/dent_amalgam-eng.php#a8
If there are no protective measures for amalgam removal, there is an increase in blood mercury for three to four days. Protective measures include rubber dam, or suction. It is best to space-out the removal of the amalgams over several days.
Some patients feel ill and malaise for a few days after amalgam removal, however this is usually short-lived. Positive effects may not be seen immediately after removal, rather, after a detoxification and chelation of mercury stores in the cells, as the removal of amalgams takes out the source of continued exposure.
Dental work causes trauma to the teeth, and under normal circumstances the tooth will recover. If a tooth or nerve dies, an abscess can form. Tooth extraction or root canals are possible treatments in this case. Taking homeopathic remedies can greatly decrease the negative side effects of dental work.
Mercury can be excreted in stool and urine via bile (3).
Hope this helps answer some questions!!
(1):Mahaffey, KR. (2005) Mercury exposure: medical and public health issues. Trans Am Clin Climatol Assoc. 116:127-153
(2): Dufault, R et al. (2009) Mercury from chlor-alkali plants: measured concentrations in food product sugar. Environ Health. 8:2
(3): Fritz, LL et al. (1995). Mercury exposure from silver tooth fillings: emerging evidence questions a traditional dental paradigm. J Dent Res. 64:1072-1075