An inlay is a customised insert that fits in your tooth. It fills gaps, limits further decay and reduces tooth sensitivity.
An onlay is placed on the exterior of a damaged or weakened tooth. They are designed to reconstruct the shape and integrity of the tooth.
Your dentist will numb the area around the tooth with an anaesthetic. They will prepare the tooth and take some impressions. A dental laboratory can then custom make your inlay/onlay. On the fit appointment, the inlay/onlay will be positioned in or on the tooth and bonded in place.