An inlay or onlay is a custom-made filling used to repair a tooth that has damage or decay.
Inlay
Fits neatly inside the grooves of your tooth
Onlay
Covers a larger area, including one or more of the tooth’s cusps (the raised parts)
They’re made outside the mouth (usually from porcelain or ceramic) and then bonded to your tooth. This helps restore strength, protect the tooth, and keep a natural look often lasting longer than a regular filling.