Inlays and Onlays — Custom Restorations Between Fillings and Crowns
Inlays and onlays are custom-made restorations bonded into a back tooth. They’re used when a tooth has more damage than a filling can support. The tooth still needs enough healthy structure to avoid a crown. An inlay sits within the cusps, the raised points of the tooth. An onlay covers one or more cusps.
If your dentist has mentioned an inlay or onlay, or you would like to understand your options for a heavily filled back tooth, book an appointment online for a calm, unhurried discussion. We see patients from Sandgate, Brighton, Shorncliffe, Bracken Ridge, and the wider northern Brisbane area.
Want to talk it through first? Call and our team can answer your questions.
- 12 Lagoon St, Sandgate QLD 4017
- Open Saturday mornings, 8:00AM to 12:00PM
- Preferred provider for HCF, CBHS, nib and HIF
Inlays and onlays at a glance
- Number of visits
- Usually two.
- Materials
- Ceramic or porcelain, composite resin, or gold. Your dentist recommends one based on the tooth, bite forces and appearance.
- How long they last
- No restoration lasts forever. It depends on bite forces, hygiene, grinding and the tooth itself.
- Fees
- We can give you an itemised plan with item numbers.
- Health funds
- Preferred provider for HCF, CBHS, nib and HIF; approved provider for Smile.com.au. What you get back depends on your policy, cover and limits.
- Where and when
- 12 Lagoon St, Sandgate QLD 4017 · (07) 3269 6252
Mon–Thurs 8:30AM–5:00PM · Fri 8:30AM–4:00PM · Sat 8:00AM–12:00PM
On this page
- What inlays and onlays are
- When an inlay or onlay may be suggested
- Inlays, onlays, fillings, and crowns — the spectrum
- Materials we use
- The benefits of an inlay or onlay
- What to expect at the appointment
- Looking after an inlay or onlay
- Who inlays and onlays may suit
- Health funds and payment
- Inlay and onlay FAQs
- Related information
- Speak to our team
What happens at your appointments
- Book online, or call (07) 3269 6252.
- We take a small digital X-ray and check how much healthy tooth remains. We discuss whether a filling, inlay, onlay or crown suits your tooth.
- The tooth is numbed and prepared. We take a scan or impression and fit a temporary cover while the restoration is made.
- At the second visit, we check the fit and bite, then bond the inlay or onlay in place.
What inlays and onlays are
Inlays and onlays are custom-made restorations bonded into a prepared back tooth. They are sometimes called indirect restorations because they are made outside the mouth — in a dental laboratory — and then bonded into place at a follow-up visit.
The difference between the two comes down to coverage:
- An inlay sits within the cusps (the raised points) of a back tooth, replacing the inner part of the chewing surface.
- An onlay extends over one or more cusps, replacing both the inner surface and a portion of the outer wall.
Both are precisely contoured to your existing tooth, then bonded to give a strong, sealed restoration that feels and functions like part of the tooth.
When an inlay or onlay may be suggested
Your dentist will usually consider an inlay or onlay when:
- A back tooth has decay or an old filling too large for a direct filling to support reliably.
- One or more cusps have fractured or are at risk of fracturing.
- You want a more durable, longer-wearing restoration than amalgam or composite for a heavily loaded molar.
- The tooth still has enough healthy structure to avoid the more extensive preparation needed for a full crown.
- An older filling is failing — see our page on replacing old fillings.
Front teeth are usually restored with composite bonding or veneers rather than inlays. Inlays and onlays are most commonly used on premolars and molars where chewing forces are highest.
Inlays, onlays, fillings, and crowns — the spectrum
It helps to think of restorations as a spectrum from least to most invasive:
- Composite or amalgam filling — placed directly in the tooth in one visit, ideal for small to moderate cavities.
- Inlay — laboratory-made, fits inside the cusps, suited to moderate to larger cavities where a direct filling may not seal or wear well.
- Onlay — laboratory-made, covers one or more cusps, used when a tooth needs cusp protection but a full crown is not yet necessary.
- Crown — covers the whole tooth, used when the remaining structure is significantly weakened or after root canal treatment.
The aim is to match the restoration to the amount and pattern of damage — restoring strength without removing more tooth than is needed.
Materials we use
Inlays and onlays can be made from several materials. Your dentist will recommend one based on the location of the tooth, the bite forces involved, and your priorities for appearance.
Ceramic and porcelain
Tooth-coloured, strong, and resistant to wear. A common choice for premolars and visible molars because they blend with the surrounding tooth.
Composite resin
Tooth-coloured and easier to repair if damaged later. Often a more economical option, but generally not as wear-resistant as ceramic for heavily loaded back teeth.
Gold
Very long-wearing and gentle on opposing teeth. Less commonly chosen today because it is not tooth-coloured, but still considered an excellent option for back molars where appearance is not a concern.
The benefits of an inlay or onlay
An inlay or onlay can:
- Preserve more healthy tooth than a crown.
- Restore chewing strength to a heavily filled tooth.
- Seal the tooth precisely and reduce the risk of further decay around the margins.
- Provide a tooth-coloured, well-contoured result on visible back teeth.
- Be longer-wearing than a large direct filling in many situations.
No restoration lasts forever. Longevity depends on bite forces, hygiene, grinding habits, and the underlying tooth — your dentist will discuss realistic expectations for your tooth at the assessment.
What to expect at the appointment
Treatment usually takes two visits.
1. Assessment and planning
We talk through what you have noticed, take a small digital X-ray, and assess how much healthy tooth remains. Where appropriate we will discuss whether a filling, inlay, onlay, or crown is the most suitable option for your specific tooth.
2. Preparation and impression
The tooth is gently numbed, the decay or old filling is removed, and the area is shaped to receive the inlay or onlay. We take a digital scan or impression and fit a temporary cover so you can eat comfortably while the restoration is made.
3. Bonding the restoration
At the second visit the temporary is removed and the custom inlay or onlay is checked for fit and bite, then bonded in place. We polish the margins, review your bite, and explain how to look after the tooth.
Looking after an inlay or onlay
Care is similar to caring for a natural tooth — gentle brushing twice a day, daily flossing, and regular check-ups and cleans. If you grind or clench at night, a custom nightguard can help protect the restoration and the surrounding teeth.
Who inlays and onlays may suit
- Patients with a moderate-to-large cavity or fractured cusp on a back tooth.
- Those replacing an old, failing filling where a direct filling may not be ideal.
- Patients who want a tooth-coloured restoration on a visible premolar or molar.
- Anyone wanting a more conservative option than a crown when enough healthy tooth remains.
If the tooth is significantly weakened, or if the nerve is involved, a crown or root canal may be more appropriate. Your dentist will explain the reasoning either way.
Health funds and payment
We are a HICAPS provider, so where you have eligible dental cover we can process your health fund claim at the practice and you only need to pay any gap. The rebate you receive depends on your individual policy, your level of cover, and your annual limits — your fund can confirm what is covered before treatment. Information on major dental cover may also be useful when planning a larger restoration.
We can provide an itemised treatment plan with item numbers so you can check your entitlements ahead of time. Payment plan options are available for larger treatment.
Inlay and onlay FAQs
How is an inlay different from a filling?
A filling is shaped directly inside the tooth in one visit. An inlay is custom-made outside the mouth and then bonded in. Inlays usually involve two visits and are chosen when a filling would be too large to seal and wear well.
How is an onlay different from a crown?
An onlay covers one or more cusps but leaves more of the underlying tooth intact than a crown. A crown covers the whole tooth and is preferred when significantly more of the tooth has been lost or weakened.
How long do inlays and onlays last?
Many last a long time when looked after, but longevity varies with material, bite forces, hygiene, and habits like grinding. Your dentist will give you a realistic picture for your tooth at the planning visit.
Will I need to take time off work?
No — both visits are normal dental appointments. Some patients have mild soreness for a day or two after the bonding visit, especially if the tooth was already sensitive.
Are inlays and onlays covered by health funds?
They are usually claimable under major dental cover, but rebates depend on your policy and annual limits. We will provide item numbers so your fund can confirm what is covered for you.
Can an old filling be replaced with an inlay?
Often yes — particularly when the existing filling is large and the surrounding tooth is starting to flex or crack. Your dentist will assess whether replacement with an inlay, onlay, or crown is appropriate.
Are inlays and onlays suitable for front teeth?
They are mostly used on premolars and molars. For front teeth, options such as dental bonding or veneers are usually more appropriate.
Related information
- Restorative dentistry
- Dental crowns
- Crown vs large filling
- Fillings
- Replacing old fillings
- Cracked teeth
- Nightguards
- Health funds
Speak to our team
If you have a heavily filled or fractured back tooth and you would like to understand whether an inlay or onlay is right for you, the team at Sandgate Family Dental is happy to talk through your options without pressure. Book an appointment online or phone the practice during opening hours.
Nervous about treatment?
Tell us when you book if you’re feeling nervous. The tooth is numbed before it’s prepared. Some people have mild soreness for a day or two after the bonding visit. Happy gas (inhalation sedation) is offered by both our dentists. It’s charged separately (ADA item 943), and it isn’t suitable for everyone, so your dentist checks your medical history first.
Visiting us
Sandgate Family Dental, 12 Lagoon St, Sandgate QLD 4017 · (07) 3269 6252
Mon–Thurs 8:30AM–5:00PM · Fri 8:30AM–4:00PM · Sat 8:00AM–12:00PM
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