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Amalgams are the name of a group of metal alloys whose main ingredient is mercury. They are formed by dissolving other metals in mercury.
How are amalgams formed?
Amalgams are mercury alloys with metals such as silver, tin, copper, cadmium and zinc. They are formed by dissolving these materials in liquid mercury.
What are the properties of amalgams?
Amalgams are very durable materials that can be easily shaped. For this reason, they have long been used as the basic material for dental fillings. Their plasticity prevented, among other things, the formation of secondary cavities in the teeth, because they filled the places after caries treatment very well, adjusting to the shape of the tooth.
What and when are amalgams used?
Amalgams are used in dentistry to fill cavities in molars that are invisible when smiling or eating. As a rule, amalgams have a dark metallic color, so they are not used for fillings in the front teeth and visible when the mouth is opened. Some dentists also abandon their use in the case of fillings in distant teeth, even in sevens or eighths.
Advantages and disadvantages of amalgams
Amalgams have both advantages and disadvantages. The undoubted advantage of this material used for dental fillings is its durability – it is the largest of all types of fillings, even greater than natural enamel. The advantage is also the ease of placing this type of filling in the cavity and the possibility of a very precise adjustment of it. During hardening, the amalgam material increases in volume (expands), which prevents the formation of secondary caries. It also has a very high durability – the amalgam filling will last up to 40 years (the composite filling – i.e. the white seal – has a lifetime of about 10 years). Contrary to the opinions of some patients, amalgam filling is also not toxic to the person who has it. The disadvantages of this type of fillings include the color contrasting with the color of the teeth, the possibility of discoloration on the teeth, the need to use cement as a base for the filling, and the electrochemical interaction between various metals present in the fillings. Mercury is also a great heat conductor, so teeth with amalgam fillings can cause pain when eating very hot or very cold meals. The main disadvantage of amalgam, however, is that the fillings made of it do not look aesthetically pleasing, so they are currently used only in some cases, with the consent of the patient.
Are amalgams harmful to health?
There is a belief among doctors and patients that the mercury contained in amalgam fillings of teeth is toxic and has a negative effect on health. However, the most exposed to the toxic effects of amalgams are not patients, but dentists. They come into direct contact with the vapors of the amalgam mercury fillings when mixing and applying the filling material. In order to minimize this adverse effect, capsule amalgams are currently used to reduce contact with mercury and the need to inhale its vapors. Scientific studies have shown that the use of cell phones leads to increased levels in the saliva and urine of people with amalgam fillings. Ecologists also emphasize that during the cremation, mercury from amalgams gets into the atmosphere, deteriorating the quality of the air we breathe. Toxic mercury fumes are also released when removing old amalgam or inserting a new one; their concentration increases in the air exhaled by the patient. According to some researchers, chewing gum also increases the release of mercury vapor from amalgam fillings. It also grows when consuming hot food and drinks. For these and other reasons, in 2017, a recommendation was adopted to completely phase out amalgam fillings by 2030. An interesting fact is that over 1/5 of all amalgam fillings used in the European Union are made in Poland. This type of fillings in molars are reimbursed by the National Health Fund, while for composite (white) fillings you have to pay out-of-pocket.
In what cases should amalgam fillings not be used?
Amalgam fillings are not recommended for children under the age of 6 and for pregnant women. They must also not be used in patients who are allergic to mercury. Autoimmune diseases are a contraindication to the use of this material in dental fillings.