Amalgam fillings are super reliable, last forever, and are tried and true in the sense that they have been used in dentistry for a century or so. So why is every dentist trying to tell you to replace your amalgam fillings with something that needs to be replaced from time to time? Is it just a ploy to grab more money off of patients by providing a subpar but acceptable service, or is there something about amalgam fillings that makes them unacceptable to today’s dentists? Sadly, the answer is in the latter.
The problem with amalgam fillings is a twofold story: they are bad for the environment and for your health. Both of these problems have to do with the fact that amalgam fillings contain high levels of mercury. Mining mercury is extremely problematic, as the only liquid metal on the periodic table is highly toxic, and contaminates ground waters and aquifers, as well as the soil it drips into, and processing it also has run offs and by products that kill anything they touch. This is why the Minamata convention was formed, to stop developed nations from using mercury, and to ban the mining and trade of mercury globally, as it is so problematic. Almost all countries in the world have signed, with the notable exception of the United States.
The other main problem with mercury is that it is toxic, and although it exists as an amalgamation with tin, silver and other stabilising elements in amalgam fillings, there is still an amount of leaching and that causes problems. The mercury negatively affects the central nervous system, and causes a variety of cancers, like leukaemia.
There are many alternatives to amalgam fillings, but each has a problem with it that makes its spread outside of the Western world very unlikely. The go to replacement is white fillings, or composite resin. This is an artificial resin that is the same colour as teeth, and that has considerably less negative health effects, but it also leaches BPA, although this is much less harmful than mercury. The problem is that it is less durable and needs to be replaced every 4-5 years or so, depending on the position of the filling and its size.
Another alternative is glass ionomer fillings, which are polymerised glass ions melted to a filling. These fillings are great because glass ions do not react with anything at all, and so there is zero leaching. While still in a liquid state they can fill any crack perfectly, and so are very flexible in their applications. The problem? Glass ionomer fillings cost way too much for most places to be able to afford them, and as such they may become popular in private clinics in the West, but even for public dental clinics in said countries, this is just not an option. Whether the material will become cheaper with mass production is also a question, or if it can be mass produced at all.
Until the issues of economic disparity are resolved, it is safe to say that most of the world will continue to rely on amalgam fillings, even if it gives them cancer, for a lack of real alternatives, and no amount of treaties and posturing by wealthy nations is going to change that. But if you are a member of a wealthy nation, than you have alternatives available for you, and we recommend getting your amalgam fillings changed as soon as possible, particularly if they are old, as they are a tax on your health and immune system.