White filling or ceramic onlay: which repair protects the tooth?
The right restoration depends less on colour than on how much healthy tooth remains and where the biting forces fall.
4 October 2026 · 6 min read · Clinically reviewed by Dr Sundeep Solanki, GDC 212282
Composite is bonded directly into a prepared tooth and works well for many small and moderate repairs. A ceramic inlay or onlay is made outside the mouth and can cover weakened cusps when a direct filling would be asked to carry too much load.
When composite is usually considered
- The cavity or fracture is limited
- Enough strong tooth remains around the repair
- The bite can be restored without leaving a thin cusp
- A repairable, direct restoration is a sensible option
When an onlay may be more predictable
A heavily restored back tooth, a crack or a missing cusp can change the calculation. An onlay can protect vulnerable parts of the tooth while preserving more tissue than a full crown in suitable cases.
What the examination decides
X-rays show decay and existing material; direct examination shows cracks, remaining walls and bite. The decision should include longevity, repairability, fee and the alternative of monitoring where intervention is not yet justified.
This article is general information, not personal dental advice. Treatment suitability is assessed individually at consultation.