In the past, amalgam fillings were the standard in repair for decayed teeth. While amalgam fillings are crafted from durable materials, the metals expand and contract with changes in temperature causing potential damage to remaining dental structure. Additionally, because the amalgam is held in place with a layer of dental cement, more dental structure needs to be removed to accommodate the filling, and over time, the cement may breakdown leading to additional decay. Tooth colored, composite resin fillings offer cosmetically and restoratively superior results. The composite resin is applied directly to the prepared teeth, shaped into position, and hardened in place with a curing light. The material does not expand and contract with temperature changes and because it is applied directly to the tooth, less healthy structure is removed and there is a reduced chance of future decay or breaking away of the restoration. Composite resin is sometimes referred to as direct bonding and in addition to being used to repair decayed, cracked, or chipped teeth, they can also be used to conceal staining and discoloration and fill gaps in teeth.