You’re chewing your lunch when part of an old filling cracks away. Or your dentist says the cavity is bigger than it looked on the X-ray. That’s often when inlays and onlays come up, and it can raise plenty of questions.
In this guide, we explain what dental inlays and onlays are and how they differ from fillings and crowns. You’ll also see what the process involves, plus signs worth raising with our team.
What Are Inlays and Onlays?
Inlays and onlays are custom-made repairs for teeth that have lost too much structure for an everyday filling. Dentists call them partial coverage restorations for back teeth, which do most of your chewing.
A standard filling is shaped inside your mouth. An inlay or onlay is made outside it, using the shape of your prepared tooth, and then bonded in place. Common materials include ceramic, which is tooth-coloured, and composite resin. Some people call a ceramic inlay a ceramic filling, though dentists use the inlay or onlay name.
Inlay vs Onlay: What’s the Difference?
The difference comes down to how much of the tooth the repair covers. The top of a back tooth has raised points called cusps, and these help you bite and chew.
- A dental inlay sits within the cusps and fills the middle of the biting surface.
- A dental onlay is a little larger. It covers one or more cusps as well, so it wraps over part of the tooth.
Because a tooth onlay reaches further, it can be used to rebuild more of the tooth than an inlay can. Both options aim to keep as much of your natural tooth as possible.
Signs a Filling May Not Be Enough
Only an exam and X-rays can show what your tooth needs. Even so, some changes are worth mentioning to our team:
- A cavity that has spread across much of the biting surface
- An old filling that has cracked, worn down, or come loose
- Decay around the edge of an existing filling
- A chipped or cracked tooth
- Sensitivity to hot or cold food, or when you bite down
- Food catching in one spot, or a rough edge your tongue keeps finding
These signs can have many causes, and a filling is often all a tooth needs. Our team can check which applies to you.
Related: Cracked Tooth: Symptoms, Types, Treatment Options and When It’s Urgent
Why a Standard Filling Is Sometimes Not Enough
At Blue Gum Dental, tooth-coloured fillings suit many cavities, and they’re often the first option we consider. Even so, fillings can’t completely repair all damage to a tooth, and every filling may need replacing at some point.
As tooth decay spreads and a cavity grows, there’s less healthy tooth left to hold a filling in place. Chewing then puts more load on the repair and on the tooth around it. In that case, our team may talk with you about an inlay or onlay. It’s made to fit your prepared tooth.
That said, the research is mixed. One systematic review compared repairs shaped in the mouth with those made outside it. It found no clear difference in fracture resistance in mechanical tests. So the right choice depends on your tooth, your bite, and what we find at your exam.
Onlay vs Crown: How Do They Differ?
A crown covers the whole tooth, a bit like a cap. An onlay covers only part of it. Which one suits you depends on how much healthy tooth remains once decay or damage is removed.
Crowns are often considered when a tooth is weaker, for example after a large break or root canal treatment. Whichever option you’re offered, our team will explain why we suggest it, and you’re welcome to ask questions.
What Happens at an Inlay or Onlay Appointment?
Every tooth is different, so our team will explain the plan for yours. In general, the steps look like this:
- Exam and X-rays: we check your tooth and the area around it.
- Numbing: if needed, we use local anaesthetic so the area is numb before we start.
- Preparation: we remove decay or an old filling and shape the tooth.
- Impression or scan: we record the shape of the prepared tooth.
- Temporary cover: if needed, a temporary restoration protects the tooth while yours is made.
- Fitting: we check the fit, bite, and colour, then bond your inlay or onlay in place.
Many cases need more than one visit, and we’ll confirm what yours involves. If dental appointments make you uneasy, tell us beforehand. At our Brentwood clinic, we strive to offer a relaxed and family-friendly dental clinic for patients. We’re happy to talk you through each step and pause whenever you need.
Caring for an Inlay or Onlay
Looking after a restoration is much like looking after your natural teeth. Brush twice a day with fluoride toothpaste and clean between your teeth daily. Regular check-ups let us check the edges of your restoration, and it’s a good idea to avoid chewing ice or very hard foods.
If you clench or grind your teeth at night, ask us about a night-time grinding splint. Like any dental restoration, an inlay or onlay may need repair or replacement over time. Check-ups help us spot changes early.
Talking Through Your Options for a Damaged Tooth
Inlays and onlays sit between a standard filling and a crown. They may suit a tooth that needs more support than a filling can give. Only an exam can show what’s right for you. Knowing your options beforehand can make that conversation feel more comfortable.
If a tooth has been bothering you, our team at Blue Gum Dental is happy to take a look. We welcome patients from Brentwood, Applecross, Ardross, Booragoon, Mount Pleasant, and nearby suburbs.
You can learn more about our dental fillings, or book a consultation with us today!
Frequently Asked Questions
Are Inlays and Onlays the Same as Fillings?
They’re related, but they’re made differently. A filling is shaped inside your mouth. An inlay or onlay is made outside it to fit your prepared tooth, then bonded in place. Our team can explain which option may suit your tooth.
Does Getting an Inlay or Onlay Hurt?
Once the area is numb, many people feel pressure rather than discomfort. Some sensitivity afterwards is common, especially to hot and cold, and it often settles over time. If it lingers or gets worse, contact our team so we can review your tooth.
How Much Do Inlays and Onlays Cost?
The cost depends on your tooth, the size of the repair, the material, and how many visits you need. Because every mouth is different, we can talk you through costs once we’ve assessed your tooth. If you have private health extras cover, it’s worth checking what your fund rebates for restorative work.
Can I Choose Between a Filling, an Inlay, an Onlay, or a Crown?
You’re welcome to ask questions and share your preferences. Our team will explain each option for your tooth. The recommendation depends on how much healthy tooth remains, where the tooth sits, and how you bite. We’ll also consider your goals and budget.