An inlay is similar to a filling, but it lies within the cusps (bumps) on the chewing surface of your tooth. An onlay is larger than an inlay. It replaces one or more decayed cusps.
Inlays or onlays can be made of gold, composite resin (plastic) or ceramics. They can last for 10 years or longer. How long they last depends on:
- The material used
- The teeth involved
- The forces of chewing
- How well you maintain them with good oral hygiene and regular visits to a dentist
The type your dentist will use depends on how much of the tooth is left.
There is also new technology that allows the dentist to have a ceramic inlay or onlay made in the office and cemented on at the same visit.
At your second visit, your dentist will take out the temporary filling and clean and dry the tooth. He or she will then cement the inlay or onlay to the tooth. Then it will be polished. Your dentist may have to shape it slightly to adjust the way your teeth come together.
Some dentists have a machine that allows the dentist to take a picture (instead of an impression) of the prepared tooth. Then a computer guides the machine in making a ceramic inlay, onlay or crown. This process can take less than one hour. Your inlay or onlay can then be cemented into place at the same visit.