Inlays, onlays and crowns are called indirect restorations, because the restoration is fabricated outside of the mouth, instead of being built in layers directly onto the teeth like a filling. An indirect restoration is called an inlay if it covers part of a tooth, without extending to a cusp (pointed tip of tooth). It is an onlay if it extends to replace a tooth’s cusp. And if it completely covers the top surface of the tooth, it is called a crown or cap.
A crown is known as a full-coverage restoration. Crowns can be used to hold together cracked teeth, cover root canal treatments, cap teeth that have been damaged by decay, and help those teeth be more resistant to further decay. Crowns can also be used to correct tooth colour and alignment defects, as well as correct structural damage to individual teeth. Having a crown placed is more invasive than getting a veneer, but it provides more reliability when added bite-strength is required.
Your dentist will take impressions of your teeth, then the restoration is shaped to match the part of the teeth it will replace. The restoration is attached with dental cement. Inlays, onlays and crowns are more effective than fillings in reinforcing teeth to withstand biting forces. Indirect restorations are also more resistant to further decay. If a tooth’s original structure is too compromised to support a filling, an indirect restoration can provide fantastic, long-lasting, beautiful results.