In general, a "filling" is a material that restores a space, void, or missing component of a tooth resulting from decay, fracture, or excessive wear. Fillings may be permanent, temporary, or sedative depending on the objective of the provider and the tooth related symptoms. The procedure required to place a restorative material will require some form of tooth preparation to ensure engineering for retention and the thickness tolerance for strength. The majority of patients who have a "filling" placed will be most comfortable with the use of a local anesthetic for the procedure.
There are two general types of filling materials; silver amalgam and composite resin. Silver amalgam restorations have a long history as a dental restorative. They are slightly stronger over time than composites, they are not cosmetic in their appearance, less expensive to place, and are tolerant to moisture contamination during placement.
Composite resin restorations are based on the concept or technology of "bonding". Placement involves an adhesive component where chemistry interacts with roughened tooth surfaces. These restorations are cosmetically pleasing, can bond weakened components of teeth to strengthen, take more time to place than silver, and do not tolerate moisture contamination during placement.