The alloy of the powder of one or more metals and mercury is called amalgam. This material has caused discussions for a long time, whether it is unhealthy or not. At a present point the EU can prohibit amalgam fillings from the member states to protect people from the toxicity of mercury.
Undoubtedly, mercury is a toxic element, but the mercury in the amalgam filling is so much mixed with the metals that in this form it can only have a minor exhalation. This is not dangerous for the patient but for the employees working with it. The main advantages of the amalgam filling are that it is cheap, it can be prepared faster than the so called “white fillings”, and it is very long lasting.
Its disadvantages are that it is not very aesthetic, it conducts hot temperatures and electricity, and according to some viewpoints it is poisonous (see: above).
The truth -as usual- is somewhere in the middle, i.e. it has some advantages and disadvantages, so after being properly informed the patient can decide what kind of filling he or she would like to have in the tooth.
Those fillings belong to this category which can also be called composite filling materials or composites. These materials can also be used for front teeth or molars, the original shape and colour of the teeth can be reproduced. Statuesque filling materials mean that the filling is put into the tooth as a paste and in a way it hardens in a cavity which was created for it.
In terms of the hardening mechanism two types of composites exist: one hardens through the effect of a catalyst in a chemical process, and the other one is more widespread, it hardens through a photo-polymerisation effect. In this case the filling is exposured to a special blue light, this causes the hardening of the material.
The favourable mechanical features and the special chemical structures of these filling materials made it possible to create a new filling technique.
During the formation of the cavity -in contrast with the methods before- a minimal amount of good tooth tissues must be extracted in order to gain a perfect set-up for the filling. This is because during the preparation of the filling we use adhesive materials which cause chemical bonds.