Onlay vs Inlay vs Crown: Which Does Your Tooth Need?
Conservative restorations save more tooth structure than crowns. Here's how dentists decide between inlay, onlay, and crown.
Dr. Fatima Hassan
General Dentist & Endodontist
Quick definitions
- Inlay: lab-made restoration that fits inside the biting-surface cavity of a tooth. Replaces damaged tooth structure without covering cusps.
- Onlay: lab-made restoration that covers one or more cusps but not the entire tooth. The middle ground.
- Crown: lab-made restoration that covers the entire visible tooth. Most coverage.
Size of restoration dictates choice
Small–medium cavity (inside the biting surface)
Inlay is often best. Preserves all cusps; stronger than a filling; long-lasting.
Cavity + one or two cracked cusps
Onlay is ideal. Replaces the damaged cusps without removing the healthy ones.
Multiple cracked cusps or very large restoration
Crown is necessary. Covering all cusps distributes force and prevents fracture.
Tooth preservation
From most conservative to most aggressive:
- Filling (direct composite) — minimal tooth removal
- Inlay (lab-made) — slightly more tooth removal for a precise fit
- Onlay — cusps prepared but not flattened
- Crown — entire tooth reduced ~1.5 mm all around
Choosing the smallest restoration that will reliably work preserves more natural tooth.
Material options
Gold (traditional, excellent)
- Longest-lasting (30+ years)
- Wears at the same rate as enamel
- Expensive; visibly gold-coloured
- Rarely used today except for back molars in patients who specifically want it
E.max (lithium disilicate)
- Strong, aesthetic, predictable
- Good for inlays, onlays, crowns
- Bonded to tooth — adds strength
- Most common premium choice
Zirconia
- Strongest ceramic available
- Slightly less translucent than E.max
- Best for molar crowns and onlays under heavy bite
- Can be milled same-day
Composite (direct)
- No lab work — done in one visit
- Less precise fit than lab-made
- Shorter lifespan than ceramic
- Best for small cavities
Lifespan
- Composite filling (large): 5–8 years
- Inlay (ceramic or gold): 15–25 years
- Onlay (ceramic or gold): 15–25 years
- Crown (ceramic): 15–20 years
Inlays and onlays last as long as crowns but preserve more natural tooth.
When root canal changes everything
A root-canal-treated tooth is significantly weaker and usually requires a crown or onlay — a filling alone is not enough. The crown distributes biting force across the tooth and prevents fracture.
Cost in Dubai
- Composite filling (large): AED 400–900
- Ceramic inlay: AED 1,800–3,500
- Ceramic onlay: AED 2,000–4,000
- Crown: AED 2,500–6,000
Inlays and onlays are similar in cost to crowns — you're mostly paying for lab work and materials, which are comparable.
The conservative mindset
A good dentist asks: "What's the smallest intervention that reliably solves this?" The answer isn't always the most expensive. In long-term cost terms, an inlay preserving cusps beats an aggressively-prepared crown that later needs retreatment.
References
- Cochrane — Indirect restorations
- Journal of Dentistry — Longevity of inlays and onlays
Referenced sources
- Cochrane
- J. Dentistry
Medical disclaimer. This article is informational and does not replace professional clinical advice. For a plan specific to your situation, book a consultation with a Paradise Dental specialist.
Related reading
Dental Inlay vs Onlay: What's the Difference?
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