Amalgam (al-malgam = ointment), Liquid mercury dissolves many metals, especially copper, silver, gold and alkali metals (lithium, sodium, potassium, ...). Amalgam can be solid, soft or liquid. Mercury also gives amalgam with some non-metals. The hardness and softness of amalgam depends on the amount of metal added.
The most obvious feature of amalgam is the decrease in the activity of the metal dissolved in them. For example, sodium, which reacts very violently with water, reacts very slowly in amalgam. Silver amalgam is used as a filling material in dentistry. Again, tin amalgam was used in the past to make mirrors. In metallurgy, various metals are separated by making amalgam. Amalgam is used as a catalyst in chemical reactions. Most amalgams decompose when heated due to the vaporization of mercury. However, copper amalgam softens when heated and hardens again when cooled.
Amalgam used in dentistry is also known as black or silver filling. Although it contains many types of metals, it is also called this because it is a metal alloy that is predominantly silver. The powder consisting of 70% silver, 23% tin, a small amount of copper and zinc is mixed with mercury in a special mixer and brought to a certain consistency, then applied to the tooth and waited for it to harden.
It has been used as a filling material in dentistry for over 150 years. During this time, it has been used in the filling of millions of decayed teeth. As a filling material used for so long, its durability and economic suitability have been proven. Despite this, rumors about amalgam are still being put forward. However, the mercury in amalgam fillings is not poisonous. When mercury combines with other metals, its chemical structure changes and it becomes harmless. The amount of mercury released in the mouth as a result of chewing and grinding is much smaller than the amount taken in water, air and food. Despite these rumors against it, it is reported by the dentists' associations of developed countries that "amalgam can be used safely in dental fillings". Amalgam should only be used in those who are definitely allergic to mercury, which is a probability much lower than one percent. Amalgam fillings should not be removed unless necessary. Because it both causes unnecessary expense and increases the possibility of damaging the tooth.
Things to consider after amalgam
The patient should not use the side where the application was made for at least one hour and should be asked to avoid chewing hard objects in that area for the following 24 hours. The patient should be given a second appointment for polishing after 24 hours. This application will both improve the metallic properties of the amalgam and provide the opportunity to review the restoration anatomically and functionally after use.
There may be a short-term hot-cold sensitivity after amalgam fillings, which disappears over time. However, although rare, some people may experience sensitivity due to electricity when there are various metals in the mouth or when another metal such as a fork is inserted. In cases of persistent sensitivity, after making sure that the sensitivity is only due to this reason, replacing the restoration with a non-metallic restorative material may be the solution.
Amalgam Indications
- In areas that may be subject to excessive load, in the back group of teeth with large caries
- In teeth with excessive tissue loss, in cases where other restorations that can be made would be more expensive,
- In individuals with poor oral hygiene,
- In patients with saliva control problems,
- For economic reasons, it can be used easily in individuals of all ages.
The American Dental Association stated in a statement
For more than 150 years and in the mouths of more than 100 million patients, amalgam filling material has been used as a reliable, healthy and durable material, and the chemical reactions of metals such as silver, copper, tin, and mercury in its content cause hard, They say that it creates a stable and safe structure.
In the extensive research conducted by the American Public Health Service in 1993 and the American National Health Institute, Dentistry Research Department in 1991, and the reports they presented as a result of these researches; "Amalgam can be used safely except for those who are extremely allergic to the substances it contains...." We take in many times more mercury from the air, water and food than we would take in from the evaporation of mercury in the amalgam filling in our mouths.
Despite being a material used for 150 years, no serious side effect more serious than the allergenicity of amalgam has been reported in scientific publications. Allergy cases do not exceed only 100 cases in 150 years. In 1991, the World Dental Association, Dental Materials Panel concluded that "There is no reason to remove amalgam fillings without a significant complaint..." The American Public Health Service stated in 1993 that "Removing and replacing amalgam fillings does not have a convincing effect that will benefit a person's health..." On the contrary, "unnecessarily removing amalgam fillings will damage the structure of healthy teeth."
Claims such as multiple sclerosis getting better with the removal of amalgam fillings or that amalgam causes diseases such as arthritis (rheumatism) and Alzheimer's are completely untrue and have no scientific basis.
The American Dental Association supports studies conducted to develop an alternative to amalgam but at least as effective and safe. However, they believe that composite resins, which are currently shown as alternatives to amalgam, are not as long-lasting and effective as amalgam, especially in large fillings.
Again, the American Dental Association and the American Public Health Service agree that "the use of amalgam for oral health is still valid..."
A study published in the November 1995 issue of the American Dental Association Journal found that 1,700 dentists had their urine tested and found very insignificant levels of mercury. If the safety precautions regarding the use of amalgam in offices are followed, there is no mercury vapor in the environment and therefore no harmful effects on the personnel.
Antithesis Arguing That Amalgam Is Harmful
Amalgam containing mercury does not only remain as a filling material in the cavity of the tooth that is decayed, as seen in the picture, but can also cause chronic mercury poisoning by slowly spreading throughout the body. If we summarize some other publications on mercury poisoning in parallel with these studies;
Animal experiments have shown that mercury spreads very quickly throughout the body and can negatively affect sensitive organs. Approximately 1 month after amalgam fillings made by Canadian scientists in sheep and monkeys, mercury accumulations were found in the stomach, intestines, kidneys and gums, and kidney functions in sheep slowed down by 50%.
After autopsy studies on humans, mercury accumulations were detected in the brain and kidneys, and the more amalgam fillings a person had in their mouth, the more mercury was found in the brain and kidneys.
Researchers Hannes Stähelin and Gianfranco Olivieri showed in laboratory studies that mercury plays an important role in the development of Alzheimer's disease when compared to normal people with deceased Alzheimer's patients who had previously had fillings made using amalgam. In addition, research on Parkinson's and MS is ongoing.
In addition, mercury negatively affects the baby while in the womb, and the more amalgam the mother carries, the more the placenta and breast milk are affected.
An Article from Türkiye
The use of dental amalgams as restorative materials has always been a controversial topic due to the mercury they contain. Although it is known that there are microleaks of mercury from amalgams, studies conducted in the last 30 years have not shown that this situation causes serious health problems.
This is a subject that has been discussed for a long time by dentists, public health experts and epidemiologists. Dental amalgams containing mercury have been in use since 1818 and have been held responsible for the development of various diseases since 1830. Especially those dealing with neuroepidemiology have been trying to shed light on this issue for years. It has been known that systemic mercury absorption has increased with this use since the 1920s.
Dental filling materials contain high amounts of mercury and the transported mercury can pass through the blood-brain barrier. Although there are many publications on the neurotoxicity of mercury, the effects of small amounts of repeated mercury exposure on the nervous system have not been clarified. Some studies have shown that there is a correlation between the amount used and the free mercury detected in the mouth and the amount of mercury in the blood and urine.
Against those who argue that mercury, like other metals, can be tolerated at low levels, some researchers state that mercury inhaled or taken orally can never be tolerated. The same authors blame dental amalgam in the etiology of some neurological diseases such as chronic fatigue syndrome, multiple sclerosis and Alzheimer's disease.
Today, the prevailing view is that amalgam does not pose an additional health problem for patients, and care should be taken in dental clinics regarding the occupational risks that free mercury exposure may pose to physicians.
