amalgam is a mercury alloy that has been used as a tooth filling since 1820. Such mixtures consist half of pure mercury and half of different metals. These include mainly silver, tin and copper, a little iridium and zinc. Silver amalgam is more chemically stable than copper amalgam and has therefore been used almost exclusively since the middle of the 20th century.
Amalgam is very durable, easy to process and superior to any other material as a modeling clay for teeth.
Amalgam is suspected to promote infections, trigger skin eczema such as muscle pain as well as chronic fatigue or headache. The topic is still scientifically controversial to this day. "From a scientific point of view, whether and how harmless or dangerous amalgam is should be viewed in a very differentiated manner; a clear statement on this is not possible due to the studies mentioned here," summarizes the German Cancer Research Center.
A contact allergy to amalgam fillings leads to problems on the mucous membrane of the mouth. More specifically, it is a hypersensitive reaction to mercury, of which amalgam is 50%. Other ingredients are copper, zinc, silver and tin - all of these metals can also cause allergies.
The amalgam allergy arises when amalgam fillings become porous, the dentist inserts or removes them, and the amalgam gets into the organism. The saliva transports it into the gastrointestinal tract and into the bloodstream, it reaches the liver and kidneys, the brain, the tissues and the nervous system.
An amalgam allergy shows up as a burning tongue, as a metallic taste in the mouth and through inflamed gums. Other possible reactions are stress and spots on the skin.
The prick test shows which substance is allergic to. The subject drops various substances on his skin and punctures them with a lancet. Twenty minutes later, the doctor sees if the skin is red or wheals.
During the patch test, the affected person is given a patch with the relevant substance on his back.
If, in the case of amalgam, eczema forms under the patch within three days, there is an amalgam allergy.
Blood and urine tests, which measure the mercury content in the body, do not prove an amalgam allergy, but a possible mercury poisoning. However, these tests are somewhat unsafe because mercury collects in particular in the tissue. It is also not clear whether the accumulated mercury comes from amalgam fillings. Many health insurance companies do not recognize amalgam poisoning as a disease, but they pay for an amalgam allergy.
Anyone suffering from an amalgam allergy, usually a mercury allergy, should avoid food that is contaminated with mercury, in particular fish that is at the top of the food chain like swordfish and tuna.
If there is an allergy, the logical consequence is to remove the amalgam fillings and replace them with other materials, such as ceramic. However, the doctor should first check the new tooth fillings to see whether they also trigger allergic reactions.
The art of the dentist is in demand, because removing the fillings can release amalgam and thus additionally harm the allergy sufferer.
Mercury accumulates in small amounts in the body even with a normal diet. However, if the amount of mercury becomes too large, mercury poisoning will result.
The metal binds to enzymes, nerve cells, neurotransmitters and membranes. The molecules change their structures and therefore no longer work. The mercury is particularly deposited in the liver, kidneys, connective tissue, nervous system and brain.
Mercury poisoning affects brain metabolism, formaldehyde breakdown, fat metabolism, vitamin balance, protein and carbohydrate balance.
With existing ones Amalgam fillings there is a risk that mercury will separate from the fillings and be swallowed or inhaled. In addition, the mercury can be absorbed through the oral mucosa or enter the brain via the olfactory nerves.
The patient takes medicinal carbon powder to protect the mucous membranes and the gastrointestinal tract, then the mouth is "sealed" with rubber so that no amalgam gets into the organism. The amalgam is removed from the teeth with a marginal incision. After removal, the doctor uses sodium thiosulfate to bind and neutralize residual amalgam.
The teeth are then filled with a substance that is compatible with the patient, a temporary filling usually being used for several months.
Ceramic, plastic or plastic-ceramic mixtures (composite) can be used as alternatives to an amalgam filling. Here is a brief overview of the advantages and disadvantages:
- plastic: Simple plastic fillings are cheap and easy to process. However, they wear out quickly and can change color. In addition, the fillings are not 100 percent tight, which can cause tooth decay at the edge of the filling. The shelf life is also rather low at three to five years.
- Composites: With this filling, around 80 percent ceramic is mixed with around 20 percent plastic. This increases the shelf life to over eight years and the look is much more natural.
- Ceramics: From a cosmetic point of view, this filling is the closest to a natural tooth. The shelf life is also remarkable at 15 years and longer. However, ceramic fillings are not included in the basic cash benefits and must be paid for yourself. This can result in costs of € 400 to € 1000 per filling.
Who should be particularly careful?
- Children with milk teeth because the growing body is sensitive to heavy metals.
- Pregnant and lactating women should not be able to use amalgam fillings.
- Retrograde root fillings must not be carried out with amalgam.
- Trepanated and cast crowns must not be closed with amalgam.
- Those with kidney problems should not use amalgam.
(Dr. Utz Anhalt)
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Dr. phil. Utz Anhalt, Barbara Schindewolf-Lensch
- Federal Institute for Drugs and Medical Devices: Brochure Amalgams in Dental Therapy, as of January 2005, agz-rnk.de
- German Bundestag: Possible health consequences for women and children when using amalgam in dentistry, 2016, bundestag.de
- German Cancer Research Center: Amalgam as cancer risk (accessed: August 22, 2019), krebsinformationsdienst.de
- European Commission, Health and Consumer Protection: Dental filling materials amalgams & alternatives (accessed: 22.08.2019), ec.europa.eu