Silver amalgam has been the material most widely used by dentists around the world to restore premolars and molars for more than a century, despite its potential toxicity due to the mercury it contains. What are the real risks for patients, and what can you do to keep a beautiful smile?
Silver amalgam is a metal alloy made up of silver (22-32%), tin (14%), copper (8%), palladium, indium and a liquid component, mercury (50%). Each of these elements is potentially toxic, but mercury is the one that worries researchers most because it is volatile at body temperature. This means that mercury vapour is constantly released from the surfaces of teeth restored with amalgam and absorbed through the mouth and, by breathing, the lungs.
The question of whether this material is dangerous to health is almost as old as the material itself and has led researchers to produce a vast body of scientific literature. According to several studies, the mercury in amalgam fillings could damage physical and mental health, while according to many others the levels of toxicity are irrelevant to human health.
Although it is known that mercury, once it enters the body, can have a toxic effect on the nervous system and kidneys, the effects of continuous exposure to minimal levels of mercury are harder to demonstrate.
However, the recent identification of numerous genes susceptible to mercury toxicity, together with the identification of subtle but not negligible side effects associated with chronic exposure to low doses of mercury, has raised the level of concern.
Norway and Sweden banned its use some years ago, mainly because of its impact on the environment, while Germany and Canada advise against using it to fill the teeth of pregnant women and children. And in Italy? The use of amalgam for fillings is expected to be banned completely from 2020.
In the meantime, since January 2019 we have complied with European regulations by equipping our clinic with an amalgam separator, so that when old restorations are removed no particles of the material are released into the waste water.
Possible symptoms caused by mercury exposure
- Chronic fatigue syndrome
- Depression, anxiety
- Fibromyalgia
- Difficulty concentrating
- Sleep disorders
- Gastrointestinal disorders
- Frequent infections
- Swollen lymph nodes
- Dry mouth
- Migraines
- Memory problems
The toxic effects of mercury are many and often appear only after a long time. Mercury toxicity frequently alters the structure and function of enzymes. These mechanisms weaken the body’s defences by causing oxidative stress, which in turn disrupts other biochemical processes, often interactively, such as the biosynthesis of certain neurotransmitters including serotonin, dopamine and noradrenaline, which can lead to depression, anxiety and other problems.
Further research is needed to better understand the link with conditions such as chronic fatigue syndrome and fibromyalgia. However, the fact that removing amalgam fillings often coincides with relief of symptoms suggests that the toxicity of the mercury in fillings may play a central role in the clinical investigation of many chronic illnesses, particularly those involving depression and chronic fatigue.
For many years, alternatives to amalgam have been available that are not only healthier but also more aesthetic (composite resin and ceramic). Composite resins in particular, which are the subject of a great deal of research, have the advantage of bonding firmly (“gluing”) to the tooth tissue and of being tooth-coloured, which makes restorations invisible.
Contact our clinic to have your fillings checked, and always remember that the best treatment is the one you never need, thanks to prevention!
Source: Janet K. Kern, David A. Geier, Geir Bjørklund, Paul G. King, Kristin G. Homme, Boyd E. Haley, Lisa K. Sykes, Mark R. Geier, Evidence supporting a link between dental amalgams and chronic illness, fatigue, depression, anxiety, and suicide, Neuroendocrinology Letters Volume 35 No. 7 2014
