Composite is the white filling material that dentists use to restore teeth. It is a fantastic material and has improved so much compared to older generation products. It is colour stable over its lifespan, it polishes well and is reasonably strong when used in the right way.
We would always consider using composite when the area to be restored is small. As composite bonds to the teeth, it is not necessary to cut large retentive restorations the way that older amalgam fillings required. Using a dental laser, areas of decay can be selectively removed without damaging healthy tooth material. In this way, the composite filling is both extremely retentive yet as small as possible.
A tooth is comprised of different layers where the underlying dentine is a yellowish colour, and the overlying enamel is white or translucent. Composite fillings can be layered in different ways to create a 3D colour matrix that matches the way a natural tooth looks. Chips on front teeth or wear around the necks of teeth will usually be done in the composite material because no further reduction of the teeth are required and it is able to match the natural aesthetics of the teeth.
The downside of composites are that they are not as wear resistant as enamel and over time will become dull and pick up stains at the margins. It is possible to polish off these stains but that can be time consuming and when too much of the composite has worn away it may be necessary to replace it.
When large areas of a tooth are missing such as from extensive decay, or injury, or when replacing a large amalgam restoration, a crown or onlay is usually considered. A crown is like a full face helmet for the tooth. It covers 360 degrees around the tooth and protects the whole visible portion of the tooth. An onlay is like a bike helmet that covers the chewing surface of the tooth but protects the tooth from flexing excessively.
Crowns and onlays were made from gold and other metals in the past, but are more frequently made from porcelain these days. See pictures in our Crown/Veneers Gallery. Many different types of porcelain are available now, some are many times stronger than a natural tooth while others can mimic natural teeth perfectly. Deciding which material gets used where is the role of a cosmetic dentist and in Sydney at least there is a definite preference for making a tooth look like a real tooth. Porcelain is therefore strong enough to withstand chewing forces on the tooth yet mimic the aesthetics of the natural enamel.
Composites might typically last 5-7 years for smaller surface restorations but much less for larger structural restorations. Porcelains on the other hand have to be known to last 10 or more years, even 20 years in the case of Lumineers Cerinate Porcelain. In summary, composite is for small fillings but larger ones should be done in porcelain.