A filling is a direct restoration used to repair a decayed or damaged tooth.
The most common materials used in fillings are Dental Amalgam (a mixture of silver, mercury, copper, tin and other trace metals), and Composite Resin (tooth-coloured synthetic material). It is possible to replace an old amalgam filling which has caused a tooth to become grey and discoloured with a tooth coloured composite material to give a more aesthetically pleasing appearance.

Before

After
We almost always use White (composite) filling materials to restore teeth.