Because as far as its chemical features are concerned, gold does not corrode, does not sinter, and it is hard to be transformed into a chemical compound. The only type of metal which does not get into reaction with oxygen and sulphur, not even at a high temperature.
Because more and more people are sensitive to various types of metals, they suffer from allergy for metal. But with the use of precious metals the later or the already known reactions can be avoided.
Beside the fact that several metals (sodium, potassium, calcium, etc.) are the essential building materials of our bodies, many metals, although not meaning any danger for the body in itself, are able to start immune reactions. The answer of your body often depends on the type of the reaction with the metal or the quantity of metal.
The inhalation of certain metal types in a great amount or a touch of a metal can also launch local irritative inflammation processes, so a smaller amount can also be dangerous. To start the allergic processes often a few microgramms of metal is enough.
The only type of filling which gets better, as time passes. The explanation for this is very simple; when using a filling with a big amount of gold, i.e. when chewing, we are hitting the edge of the filling more and more into the edge of the tooth, therefore when sticking to the tooth perfectly the filling prevents the secondary development of caries.
This is the only type of filling which is absolutely biologically compatible, i.e. its material has no unhealthy effects at all.
Here we do not prepare the cavity in the usual way because the filling prepared in the laboratory must be slipped later to its place, so we must pay attention that the walls of the cavity should converge with a few grades coming deeper into the cavity.
The filling is prepared by a dental technician according to the impression. Since there is no need to worry that the material will harden before the given time, there is plenty of time to create the most beautiful and ideal forms.
Having fixed the filling, we carefully have to polish the edge of the gold to the tooth, and so the most durable type of filling is finally ready.
If the colour of gold disturbs the patient aesthetically (although it is more beautiful than the blackened amalgam) the problem can be solved by putting a porcelain shell on the top of the gold after having chosen the appropriate colour of tooth.