Dental fillings are built to last — but they’re not designed to last forever. Over time, even the most well-placed filling can wear down, crack, or become loose, leaving your tooth vulnerable to further damage or decay.

If you’ve had a filling for more than a few years, it’s worth checking in to see whether it’s still doing its job. Many people don’t realise that their fillings have reached the end of their lifespan until they experience pain or complications.

Here are six signs it may be time to replace an old filling — and why it’s worth getting ahead of the problem before it becomes a bigger issue.

1. You’re experiencing sensitivity or pain

A tooth that’s been previously filled should feel stable and pain-free. If you begin to notice sensitivity to hot, cold, or sweet foods — or any sharp pain when biting down — it could be a sign that the filling is no longer sealing the tooth properly.

This often means that bacteria have entered the tiny gap between the filling and the natural tooth, potentially causing new decay or inflammation in the nerve.

What to do:
Don’t ignore sensitivity, even if it comes and goes. A quick check can determine whether the filling needs to be repaired or replaced before further damage is done.

2. You’ve noticed a change in shape or texture

Run your tongue over your tooth — does it feel different than it used to? Fillings can wear down or chip away gradually, especially if they’re located on the biting surfaces of your molars.

Changes you might notice include:

• Rough or sharp edges
• A “dip” or divot in the centre of the tooth
• Feeling like your bite has changed or no longer aligns comfortably

Worn or misshapen fillings are more likely to fracture or allow bacteria in, leading to hidden decay.

What to do:
Your dentist can smooth or reshape the area — or replace the filling entirely if needed — to protect the tooth and restore function.

3. The filling has cracked or fallen out

Sometimes, fillings fail suddenly. You might feel a crack while eating or discover that a chunk of your filling has broken away or disappeared entirely.

This is particularly common in older amalgam (metal) fillings, which can expand and contract with temperature changes, eventually weakening the surrounding tooth.

What to do:
A missing or cracked filling leaves the tooth exposed and vulnerable. Book a visit promptly to avoid further breakage or infection. In some cases, a crown may be needed to protect the remaining tooth structure.

4. There are visible stains or dark edges

If your tooth or the edge of your filling is starting to look dark, discoloured, or stained, it may be more than just a cosmetic issue.

Staining around the edges of a filling can be a sign that the bond between the tooth and the material is beginning to fail. This allows bacteria, food particles, and plaque to collect — increasing the risk of decay underneath the filling.

What to do:
Your dentist can assess whether the stain is surface-level or a sign of deeper issues. In many cases, a simple replacement can restore the tooth’s integrity and appearance.

5. It’s been many years since it was placed

Most fillings have a lifespan of 5–15 years, depending on the material, the size of the filling, and how well you’ve cared for your teeth.

If it’s been a decade (or more) since your last filling was placed, it may be nearing the end of its useful life — even if you haven’t noticed any problems yet.

What to do:
Regular check-ups allow your dentist to monitor older restorations and recommend timely replacements before failure occurs. Waiting until there’s pain often means more complex treatment is required.

6. Your dentist has raised concerns during a check-up

Sometimes, a filling can look fine on the surface but show signs of breakdown on an X-ray or during an examination. Your dentist may notice gaps, movement, or decay around the edges that you can’t see or feel.

Trusting this advice — even if nothing hurts — can save you from bigger problems like root canal treatment or tooth loss down the track.

What to do:
If your dentist recommends replacing a filling, it’s usually because they’ve spotted early signs of failure. Acting sooner rather than later can preserve your tooth and avoid unnecessary discomfort.

Prevent problems before they start

Fillings are one of the most common dental treatments — and when maintained properly, they can last for many years. But like anything, they require upkeep.

Whether you have one filling or several, regular check-ups help ensure they’re still protecting your teeth the way they’re meant to.

Time for a review?

If you’ve noticed changes in your fillings or it’s been a while since your last visit, now’s a great time to have things checked. A simple replacement now could save you from more invasive treatment later.

Visit us for a comprehensive review and let’s make sure your fillings — and your smile — are still going strong.