Inlay or Crown – What's the Difference
When a tooth is too damaged for a simple filling but does not yet require a full crown, an intermediate solution exists: the inlay, onlay, or overlay. Understanding the differences between these restoration types helps patients understand why their dentist recommends a particular treatment.
The Spectrum of Restorations
Filling: A direct restoration placed in a single appointment. Suitable for small to moderate cavities where the surrounding tooth structure is sound.
Inlay: An indirect restoration fabricated in a dental laboratory and bonded into a prepared cavity. Covers the space between the cusps (the raised points of a molar) without extending over them. Suitable for moderate cavities where a filling would be too large to be durable.
Onlay: Similar to an inlay but extends over one or more cusps of the tooth. Used when cuspal coverage is needed for structural protection.
Overlay: Covers most or all of the occlusal (biting) surface of the tooth, but does not extend down the sides like a crown.
Crown: Covers the entire visible surface of the tooth above the gum line. Required when the tooth has lost so much structure that the remaining tooth cannot reliably support an inlay or onlay.
Why Choose an Inlay Over a Large Filling?
A direct composite filling in a large cavity requires the dentist to build up the restoration layer by layer inside the mouth. In large cavities, this technique has limitations: shrinkage during curing, difficulty achieving optimal contour, and reduced long-term durability.
An inlay is fabricated outside the mouth under ideal laboratory conditions. The result is a precisely fitting, highly polished ceramic or composite restoration with excellent marginal seal, natural appearance, and superior durability compared to large direct fillings.
Why Choose an Inlay Over a Crown?
A crown requires the removal of a significant amount of healthy tooth structure from all sides of the tooth. An inlay removes only the decayed or damaged tissue, preserving far more natural tooth. Where an inlay can provide sufficient structural support, it is always preferable to a crown.
At Smilecraft, we apply the principle of minimal intervention: using the most conservative restoration that will reliably restore function and aesthetics. Our digital design and milling technology allows us to produce inlays and onlays with exceptional precision and a natural appearance.
