Onlay
An indirect extracoronal restoration that covers one or more cusps of a posterior tooth, providing greater protection than an inlay but less than a full crown.
Full Definition
An onlay is an indirect dental restoration that extends over the occlusal surface and one or more cusps of a tooth, fabricated outside the mouth and cemented in place. It is indicated when tooth tissue loss is too extensive for an inlay but a full crown preparation is not yet warranted. Onlays may be constructed from gold, ceramic, or composite resin. Editors must ensure that 'onlay' is not used interchangeably with 'inlay' or 'crown' in clinical records, as these represent distinct procedures with different preparation designs and cost implications. In some documents, 'overlay' is used for a restoration covering all cusps short of a full crown.
Usage
Usage note: Not synonymous with 'inlay' or 'crown'. Always confirm cusp coverage extent in clinical records before assigning the term.
In Context
- "Due to extensive buccal cusp fracture, a gold onlay was prescribed for LL6 rather than a standard inlay." — Restorative treatment planning note
- "The lab ticket incorrectly described the restoration as an inlay; clinical notes confirm this is an onlay with full cusp coverage." — Laboratory correspondence review