What is the difference between an onlay, and a crown?
Onlays, and crowns are different ways to replace missing or broken tooth structure. How a dentist chooses between which restoration depends on how many teeth you are trying to replace. An onlay covers only portion of a tooth, and removes minimal tooth structure. Onlays are generally a more conservative approach. The ceramic onlay fits similarly to a puzzle piece and can blend in so well that often times you can't see where the tooth starts and the onlay stops. They are often used as alternatives to large fillings. When a white filling it too large, it often fails after a few years due to the tooth breaking down or a cavity. The white fillings are simply not as strong as ceramic and gold.
A crown requires that the tooth is trimmed down and covered completely to the gumline. Both onlays and crowns can be made from ceramic or gold. The benefit of the ceramic onlay is the ability to match your tooth color. In areas where the material cannot be seen gold is a great choice because gold fits the closest against the tooth and it is extremely strong. Studies have shown that a gold onlays and crowns have lasted for 50 years! Onlays and crowns are made the same way. The dentist prepares the tooth, takes an impression, sends it to the lab to fabricated, and the tooth is cemented in at the following appointment. Onlays and crowns are important ways dentists can help save and preserve your teeth.