A dental inlay and dental onlay are types of indirect restorations used when a tooth is too damaged for a standard filling but not damaged enough to require a full crown. They are custom‑made outside the mouth (usually in a dental laboratory) and then bonded to the tooth for strength, durability, and a precise fit.

What is an Inlay?

A dental inlay fits inside the chewing surface of the tooth, sitting neatly within the grooves without covering the cusps (the raised biting points). It is used when damage or decay is moderate and confined to the centre of the tooth. Inlays provide a strong, long‑lasting alternative to large fillings and are commonly made from porcelain, composite resin, or gold.

What is an Onlay?

A dental onlay is similar to an inlay but extends over one or more cusps of the tooth. Because it covers part of the biting surface, it is sometimes called a partial crown. Onlays are recommended when damage is more extensive but the tooth still has enough healthy structure to avoid a full crown. They reinforce weakened cusps and help prevent future fractures.