What to look for in a filling
Tooth fillings of any kind should be able to do three things: stop bacterial infections from spreading, seal up affected bits of tooth material, and last a long time. If we take these three things into account, there isn’t that much difference between the fillings themselves. Sure amalgam fillings last a lot longer than tooth coloured white fillings, but they have the chance of not filling up the cavity entirely and having an infection on the sides of the tooth fillings, which will require new fillings. Sure amalgam is more antibacterial, but white fillings seal up the hole perfectly. So really, while one filling may be stronger in some respects than the other, there is very little difference. Here is a breakdown:
Durability: Amalgam fillings
Antibacterial strength: Same
Sealing: Tooth coloured fillings
The Crucial Difference
The crucial difference that makes white fillings undoubtedly better than amalgam fillings lies in the chemical makeup of the fillings themselves. Amalgam fillings leach mercury into your system and they also have trace amounts of lead and other harmful heavy metals. They conduct electricity and can be harmful to your central nervous system. Besides that, mining mercury is extremely bad for workers and the environment, and can as it is a liquid, it can leach into aquifers and contaminate soil for centuries. This crucial difference makes amalgam less desirable. To combat the environmental exploitation associated with the mercury industry, the Minamata convention was signed, and the UK is a part of it.