Dental Amalgam, also known as Silver Filling material is a mixture of Mercury and Metal Alloy’s used to fill a hole in a tooth after decay has been removed by a dentist. Amalgam commonly consists of Mercury (50%), Silver (35%), Tin (13%), Copper (2%) and other trace metals like Zinc. Dental amalgams were first documented in a Tang Dynasty medical text written by Su Kung in 659 AD, and appeared in Germany around 1528. In the 1800s, amalgam became the dental restorative material of choice due to its low cost, ease of application, strength, and durability. Recently however, concern for appearance, environmental pollution, health, and the availability of improved, reliable, composite (white) filling materials have diminished its popularity. In particular, concerns about the toxicity of mercury have made its use increasingly controversial.
What is Mercury and why is it so toxic?
Mercury is a chemical element with symbol Hg and atomic number 80 (which is a pretty high number). It is commonly known as quicksilver. The reason that Mercury is so dangerous is that Mercury is the only metal that is liquid at standard temperature and pressure: in fact, there is no other metal that can remain liquid in a wider range of conditions. This is mostly due to the abnormal behavior of the electrons orbiting the atom and makes it one, of the only 5 elements, to be liquid in a normal state.
But the real dangerous property of mercury is its density. Mercury is 13.5 times denser than water. It’s liquid and gas forms are highly poisonous. When inhaled or ingested, Mercury can accumulate in the body, slowly degrading the membranes of important organs like the brain, nervous system, kidneys or liver. It can cause varying effects from eye irritation and vomiting to DNA and chromosomal damage. Mercury can be found naturally in the environment, present around the world as “Cinnabar”. Although it has always been released into the environment through normal weathering, the recent rise in its quantity on the globe has many people worried. Because it is not naturally found in food, there is a worry that we could be ingesting dangerous amounts of it simply as a result of the natural food chain,