Restorative Dentistry
Inlays and Onlays in Darwin
A conservative, long-lasting restoration for damaged back teeth — stronger than a filling, less invasive than a crown. Available in porcelain and composite at Compass Dental Care, Parap.
Inlays vs Onlays — What Is the Difference?
Both inlays and onlays are custom restorations for the chewing surfaces of back teeth. The distinction lies in how much of the tooth they cover:
Inlay
Fits within the cusps of the tooth — into the central cavity area. Used when the damage or decay is confined to the centre of the tooth and the surrounding cusps are intact and sound.
Onlay
Extends over one or more cusps of the tooth. Used when the damage or decay extends to the cusp tips, or when a cusp has fractured — requiring support that an inlay cannot provide but without the full coverage of a crown.
Both are fabricated in a dental laboratory to precise measurements and bonded permanently to the tooth. The fit is superior to a directly placed filling, which can shrink slightly as it sets.
Why Choose an Inlay or Onlay Over a Filling or Crown?
The choice between a filling, inlay/onlay, and crown comes down to how much of the tooth is damaged and how much load the restoration needs to bear:
Filling (direct restoration)
Ideal for small to medium cavities. Placed in one visit. May shrink slightly on setting. Can weaken the remaining tooth structure in larger cavities by requiring the tooth to flex around the filling.
Inlay / Onlay (indirect restoration)
Ideal for moderate to large cavities where the cusps need reinforcement. Fabricated in a laboratory for a precise fit. Bonds to and strengthens the remaining tooth. More durable than a filling, more conservative than a crown.
Crown (full coverage restoration)
Needed when the tooth is severely damaged, cracked, or has had root canal treatment. Covers the entire visible tooth. Requires more tooth structure to be removed than an inlay or onlay.
Materials: Porcelain vs Composite
At Compass Dental Care, Darwin, we offer inlays and onlays in porcelain and composite resin. Each material has its advantages:
Porcelain
Excellent aesthetics — matches the colour and translucency of natural tooth enamel very closely. Highly resistant to staining and wear. Generally considered the most durable option for inlays and onlays. Ideal for visible back teeth where appearance matters.
Composite Resin
Tooth-coloured and natural-looking. Can be somewhat easier to repair if damaged. May be more economical in some circumstances. Not quite as hard-wearing as porcelain for teeth under heavy chewing forces, but a strong and reliable choice for many patients.
Dr Pham will discuss which material is most appropriate for your tooth's position, size of the restoration, and your bite during your consultation at our Parap clinic.
Frequently Asked Questions
What is the difference between an inlay and an onlay?
An inlay sits within the cusps of a back tooth and replaces material in the central part. An onlay extends over one or more cusps, making it suitable when a larger area of the tooth needs to be replaced. Both are custom-made and provide more coverage than a filling while preserving more natural tooth than a crown.
How long do dental inlays and onlays last?
Porcelain inlays and onlays can last fifteen to thirty years or more with good oral hygiene and regular check-ups at our Darwin clinic. Longevity depends on the individual's bite, diet, and oral hygiene. Composite options are also strong but may not last quite as long as porcelain.
When is an inlay or onlay a better choice than a filling or a crown?
An inlay or onlay is typically the right choice when a tooth has too much damage to be reliably repaired with a filling, but not enough damage to justify removing the additional tooth structure required for a crown. Dr Pham will assess the tooth and recommend the most conservative restoration that will be strong enough for your bite.
Are inlays and onlays covered by health insurance?
Inlays and onlays may attract a health fund rebate depending on your level of cover. We process HICAPS claims on the spot at our Parap, Darwin clinic. We recommend checking your policy or calling your fund before your appointment to understand your entitlements.
How many appointments does an inlay or onlay take?
Typically two appointments. At the first visit, the damaged tooth structure is removed, an impression is taken, and a temporary filling is placed. At the second visit (one to two weeks later), the temporary is removed and the permanent inlay or onlay is bonded in place.
Related Services
Protect Your Back Teeth with an Inlay or Onlay
Book a consultation at Compass Dental Care, Parap Darwin. Saturday morning appointments available. Free on-site parking.
