These are used to restore any holes in the teeth, when there is damage to the tooth due to either the disease process or due to trauma. Overall, there are two types of material available for this, tooth-colored material which is known as composite, and also the metal-colored material, which is know as amalgam. You find composite fillings are used in area of the mouth where appearance is important, as these match the shade of the teeth. These can be used in areas where there is use of the teeth as well, such as the chewing surfaces of the back teeth. The metal-colored fillings are used mainly in the areas where there is more load on the teeth, such as chewing surfaces. These tend to be used less nowadays due to it being more of a historical material, but due to its well-proven history, can be used in certain clinical circumstances.