A Dental filling is a way to restore teeth that are damaged by decay back to their normal function and shape. When any dentist gives the filling, he or she first removes the decayed tooth material, cleans the affected area, and then fills the cleaned out cavity with a specific filling material. Dentists consider a number of factors when choosing which type of filling material is best for you. These factors include the extent of the repair, where in your mouth the filling is needed and the cost.
Lack of durability — composite fillings wear out sooner than amalgam fillings (lasting at least five years compared with at least 10 to 15 for amalgams); in addition, they may not last as long as amalgam fillings under the pressure of chewing and particularly if used for large cavities.
Today, several dental filling materials are available. Teeth can be filled with gold; porcelain; silver amalgam (which consists of mercury mixed with silver, tin, zinc, and copper); or tooth-colored, plastic, and materials called composite resin fillings.