A tooth requires a filling when it has become damaged or it has lost some tooth structure. This is usually caused by dental decay or can also be caused by trauma such as a chipped tooth.
At Big Smiles we use tooth coloured filling materials to replace damaged tooth structure. Most fillings are done with a composite resin material which is very strong while at the same time very aesthetic.
When a large amount of tooth structure is lost then porcelain is usually required in the form of an onlay, inlay or crown. (See Crowns & Bridges)