An inlay or onlay is a restoration made outside the mouth and then attached to a prepared tooth. The terms describe how much of the tooth it covers. This type of restoration should not be confused with a post placed inside a root canal.
How is it different from a filling or crown?
A direct filling is shaped in the tooth. An indirect restoration is made from an impression or scan and fitted later. A crown covers the tooth more extensively. The choice depends on the size of the defect, the strength of the remaining walls and biting forces.
What do the names mean?
An inlay generally fits between the tooth’s cusps. An onlay covers at least one cusp, while an overlay covers the chewing surface more extensively. Terminology can vary, so ask the dentist to show you the planned coverage on your tooth.
How is it prepared?
After assessment and preparation, an impression or scan is taken. The production method and number of visits depend on the treatment arrangements. Fit, attachment and checking the bite are important when it is placed.
Ask about the material, repair options and protection of the remaining tooth. The restoration does not remove the need to prevent decay, especially at its margins. Report pain on biting or a contact that feels too high rather than waiting for the tooth to adjust by itself.