Inlays and Onlays: When a Filling Isn’t Enough (and a Crown Isn’t Needed)
Not every damaged tooth fits neatly into “needs a filling” or “needs a crown.” When decay or damage is more extensive than a filling can address, but the tooth still has enough healthy structure that a full crown isn’t necessary, an inlay or onlay is often the option in between.
Where a Standard Filling Reaches Its Limit
A filling works well for smaller areas of decay, where enough of the tooth’s natural structure remains around it to support the material. As the affected area gets larger — particularly across the chewing surface or involving one of the tooth’s cusps — a filling has less remaining structure to bond to and support, which affects how well it holds up under the pressure of biting and chewing.
This is the point where an inlay or onlay is often considered instead.
What’s the Difference Between an Inlay and an Onlay?
Both are custom-made restorations, fabricated to fit the specific tooth rather than shaped directly in the mouth the way a filling is.
- An inlay restores the area within the cusps of the tooth, similar in placement to a filling but as a separately made piece rather than a material placed directly into the cavity.
- An onlay extends further, covering one or more of the tooth’s cusps where the damage or decay affects a larger portion of the chewing surface.
Which one applies depends on how much of the tooth structure is affected, which is assessed by your dentist rather than something that can be determined beforehand.
Why Not Go Straight to a Crown?
A crown fits over the whole visible part of the tooth, which involves removing more of the tooth’s remaining structure to fit it. An inlay or onlay is a more limited approach, addressing the damaged area specifically while keeping more of the natural tooth intact where it’s still healthy.
This isn’t the right approach in every case — if the damage is extensive enough, or the remaining tooth structure is too compromised, a crown may still be the more appropriate option. That assessment is made by examining the tooth directly, including X-rays where needed.
What the Process Involves
Treatment with an inlay or onlay often requires two appointments:
- First appointment — the affected area of the tooth is prepared and any decay removed. After the tooth is prepared, an impression or digital scan is taken. For laboratory-made restorations, this information is sent to a dental laboratory so that the inlay or onlay can be made, and a temporary restoration is typically placed in the meantime.
- Second appointment — the finished restoration is checked for fit, adjusted as needed, and bonded into place.
Material Options
Inlays and onlays can be made from a few different materials, including porcelain, composite resin, or gold, each with different properties around appearance, wear resistance, and cost. Which material suits a particular case depends on the tooth’s location and the degree of damage, as well as individual factors your dentist would discuss with you directly — this isn’t a one-size-fits-all decision. Results and durability vary between patients and materials.
Risks and Limitations
As with any dental restoration, an inlay or onlay isn’t without limitations; the tooth still needs to be prepared, which involves removing some natural tooth structure at the affected site. Bonding can, in some cases, fail over time and require re-attachment or replacement.
Sensitivity in the tooth following the procedure is possible, similar to other restorative treatments. How well a restoration holds up over time depends on factors including oral hygiene, bite force, and general wear, and results vary from person to person — this is something to discuss with your dentist rather than assume applies uniformly.
Caring for an Inlay or Onlay
Ongoing care is largely the same as for a natural tooth — regular brushing, flossing, and check-ups. Your Cabramatta dentist will check the restoration at routine visits as part of a general exam, watching for any signs of wear, decay at the margins, or the restoration coming loose.
Frequently Asked Questions
How do I know if I need an inlay, onlay, or a crown?
This depends on how much of the tooth’s structure is affected by decay or damage, which is assessed through a clinical exam and, where needed, X-rays. It can’t be determined without that assessment.
Do inlays and onlays hurt?
The procedure is carried out with local anaesthetic to manage discomfort, and some sensitivity afterwards is possible, similar to a filling or crown. Individual experiences vary.
Are inlays and onlays better than a regular filling?
They’re used in different situations rather than being a universal upgrade — a filling remains the appropriate option for smaller areas of decay. An inlay or onlay is considered when the damage is more extensive than a filling is suited to, but doesn’t require a full crown.
How long do inlays and onlays last?
This varies between patients depending on the material used, oral hygiene, and bite force, among other factors. Your Cabramatta dentist can talk through what to expect for your specific situation at your appointment.
Inlays and Onlays in Cabramatta
If you’ve been told a tooth needs more than a filling, or you’d like to understand your restoration options before deciding, we’re happy to talk it through at an assessment.
Call us on (02) 9755 5300 or book online. We’re at 47 Arthur St in Cabramatta, and we see patients from Cabramatta, Canley Vale, Fairfield, Bonnyrigg, and Liverpool.
Any surgical or invasive procedure carries risks. Before proceeding, consider seeking a second opinion from an appropriately qualified health practitioner.