A composite resin filling (also known as a white filling) is a tooth-colored plastic mixture filled with glass (silicon dioxide) and is a composite quartz resin that usually contains some sort of light sensitive agent.
Introduced in the 1960s dental composites were confined to the front teeth because they were not strong enough to withstand the pressure and wear generated by the back teeth. Since then composites have been significantly improved and can be successfully placed in the back teeth as well. Composites are not only used to restore decayed areas but are also used for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth. A composite filling can be tinted to match any tooth color and it forms a natural bond with the existing tooth in a way that metal fillings cannot. The end result is nearly invisible fillings.
In order to bond a filling material to your tooth it is first necessary to remove decay prepare the tooth and then to condition the enamel and dentin. Once conditioned a thin resin is applied which bonds to the etched surface. Placement time depends on the size and location of the cavity and the larger the size the longer it will take. After placement composites are hardened by shining an intense light on them for a specified period of time usually around 40 seconds.
Composite fillings tend to be used as an alternative to metal or silver amalgam fillings and are used to treat decay on a portion of a tooth replace an old silver amalgam filling and to maintain a white smile.
Composite fillings are more than just attractive and they have distinct advantages over other types of fillings especially metal ones. Composite fillings are environmentally non-toxic because they use no mercury. They are stronger because they bond directly to the surface of the tooth. They protect the tooth from fracturing because they don't require the severe ﾔundercutﾔ (removal of healthy tooth structure) of mercury fillings.
There are some disadvantages to composite fillings and these include the fact that the initial investment in a composite filling is higher than that for a mercury filling. This is due to the fact that the composite material is more expensive and the restoration is more difficult and time consuming to place. However this initial higher investment is offset in the long run by the health benefits and reduced likelihood of restoring potentially fractured teeth.
Another type of 'white filling' is called a Composite or Porcelain Inlay. These fillings are usually placed in back teeth when esthetics is of utmost concern in order to increase their strength and longevity they are fabricated in the laboratory and then bonded into position at the dentists.