Filling You In: Everything You Need to Know About Tooth Filling

A little tooth sensitivity here, a rough edge there it's easy to brush off the early signs of a cavity. But cavities don't fix themselves, and catching one early is the difference between a simple filling and a much bigger (and more expensive) procedure down the line.

This guide walks you through how to recognise the warning signs, what actually happens once you're in the chair, and what to expect in the days after so you know exactly what you're dealing with, and when it's time to book a check-up.

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Signs You Might Need a Filling

Cavities are often silent in the early stages, which is exactly why they're easy to ignore. Here's what to watch for:

• Sensitivity to hot, cold, or sweet food and drink that lingers after the trigger is gone

• A dull ache or sharp pain when biting down

• Visible dark spots, brown staining, or small holes on the tooth surface

• A rough patch or edge you can feel with your tongue

• Food constantly getting stuck in the same spot

• Persistent bad breath that doesn't improve with brushing

• An old filling that feels loose, cracked, or has changed colour
  

If any of these sound familiar, it's worth getting it looked at before it progresses; even a small cavity can grow quickly once the enamel is breached.

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What Happens If You Leave a Cavity Untreated

It's tempting to wait it out, especially if the discomfort comes and goes. But untreated decay doesn't stay contained; it spreads deeper into the tooth over time.

• The decay moves from enamel into dentin, then toward the nerve, increasing sensitivity

• and pain

• What could've been a simple filling may progress to needing a root canal

• Severe decay can lead to infection, abscess, or in some cases, tooth loss

• Delaying treatment usually means a longer, more involved appointment later
  

The takeaway: a filling now is almost always simpler than the alternative later. If you're noticing any of the signs above, it's worth booking a check-up sooner rather than later.

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What to Expect During Recovery

Getting a filling is a routine, well-tolerated procedure, but knowing what's normal afterwards helps you avoid unnecessary worry.

In the first few hours

• Numbness from the local anaesthetic typically lasts 1-3 hours. Avoid hot drinks or chewy food until it wears off to prevent accidentally biting your cheek or tongue

• Mild sensitivity to temperature or pressure on the filled tooth is common and usually settles within a few days
  

In the days after

• It's normal for the tooth to feel slightly different when biting for a day or two as you adjust

• If your bite feels uneven or the tooth is painful to bite on after a few days, it likely needs a small adjustment. This is quick and normal, so don't hesitate to call

• Ongoing sharp pain, swelling, or sensitivity that worsens rather than improves is worth getting checked promptly

Most people are back to eating and drinking normally within a day, once any numbness has fully worn off.

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How Long Do Fillings Last?

Filling lifespan depends on the material used and how well the tooth is cared for afterwards, but as a general guide:

Filling Material	Typical Lifespan
Composite (tooth-coloured)	5-10 years on average
Glass ionomer	5 years, often used for smaller or temporary restorations
Gold or ceramic	15-20+ years with good care

Regular check-ups let your dentist catch a worn or cracked filling before it fails -replacing one early is far simpler than dealing with new decay underneath it.

Frequently Asked Questions

1. Can a filling fall out?

Yes, though it's uncommon with proper care. Fillings can loosen over time due to wear, a new cavity forming around the edges, or biting down on something hard. If yours feels loose or falls out, book an appointment as soon as possible the exposed tooth is vulnerable to further decay.

2. Does a new filling change how my tooth looks?

Composite and ceramic fillings are colour-matched to your natural teeth, so the change is minimal to invisible. Older amalgam (silver) fillings are more noticeable, which is one reason many patients now choose tooth-coloured alternatives.

3. Is it normal for a filling to hurt weeks later?

Mild sensitivity in the first couple of weeks is normal as the tooth settles. Pain that persists beyond that, or that's sharp and worsening, isn't typical and should be checked; it can sometimes mean the bite needs adjusting or, rarely, that the nerve was irritated during treatment.

4. Can I eat and drink normally straight after?

Wait until the numbness fully wears off (usually 1-3 hours) before eating, to avoid biting your cheek or tongue. After that, most people can eat normally, though it's sensible to avoid very hard or sticky foods on that tooth for the first day.

5. How do I know if my old filling needs replacing?

Watch for visible cracks, a rough edge you can feel, staining around the margins, sensitivity that's new or worsening, or a filling that feels loose. If in doubt, it's a quick thing for your dentist to check at a routine visit.

When to See a Dentist

If you're noticing any of the warning signs above, or it's simply been a while since your last check-up, don't wait for it to turn into something bigger. Our team can assess the tooth, explain your options, and get it sorted with minimal fuss.