onlay

onlay — noun

1. A thin piece of metal, ceramic, or other hard material that a dentist fixes onto

1.nounB2
Definition

A thin piece of metal, ceramic, or other hard material that a dentist fixes onto a damaged tooth to cover and protect its broken surfaces, used when a filling is too weak for the damage.

Example

After the crack reached her molar's edge, Dr. Park suggested an onlay instead of a larger filling.

contrast: onlay vs. filling

The ceramic onlay matched Yuki's other teeth so well that no one could see it.

Common collocations
  • ceramic onlay
  • gold onlay
  • metal onlay
  • onlay restoration
  • onlay procedure
Synonyms
  • dental crown

    A crown covers the entire tooth; an onlay covers only part of it.

Usage Note

Distinguish from an 'inlay' — an inlay sits inside the tooth's cusps, while an onlay extends over one or more cusps to protect the entire chewing surface.

Common Mistakes

The dentist put an inlay on my back tooth to cover the whole surface.
The dentist put an onlay on my back tooth to cover the whole surface.
an inlay fits inside the tooth; an onlay covers the cusps.

2. A piece of bone, cartilage, or other tissue that a surgeon places on top of a da

2.nounC1
Definition

A piece of bone, cartilage, or other tissue that a surgeon places on top of a damaged body part — for example, a broken shin or a weak jawbone — to help the body rebuild itself.

Example

The surgeon took a piece of bone from Amir's hip and placed it as an onlay on his shin.

donor site to recipient site

After the accident, Priya needed a bone onlay to rebuild her lower jaw.

Common collocations
  • bone onlay
  • cartilage onlay
  • onlay graft
  • onlay technique
  • onlay procedure
Synonyms
  • graft

    A broader term; an onlay is a specific type of graft applied to the surface.

Usage Note

In surgery, 'onlay' contrasts with 'inlay graft' (which is placed inside a defect). An onlay sits on the surface and is often used to build up a weakened area.

Common Mistakes

The surgeon used an onlay graft inside the bone cavity.
The surgeon placed an onlay graft on the surface of the bone.
an onlay goes on top of the tissue, not inside a cavity.