Fillings are durable, but not permanent — they're subjected to constant chewing pressure and temperature changes for years, and eventually wear out or fail. Catching the warning signs early usually means a simple replacement rather than a more involved procedure.
How long fillings typically last
Composite (tooth-colored) fillings generally last 5 to 10 years, while older amalgam (silver) fillings can last 10 to 15 years or longer, though they're more prone to cracking the surrounding tooth over time due to how they expand and contract. Neither is designed to last indefinitely.
The warning signs worth watching for
- Visible cracks, chips, or rough edges around the filling
- New sensitivity to hot, cold, or sweet foods in a tooth that was previously comfortable
- A dark line or shadow forming at the edge of the filling, which can indicate a gap where bacteria are getting in
- Pain when biting down on that specific tooth
- A filling that feels loose, or one that has visibly fallen out
Why a small gap matters more than it looks
Once a filling develops even a tiny gap at its edge, bacteria and food particles can work their way underneath it, where a toothbrush can't reach. Decay then progresses hidden beneath the existing filling, often without pain until it's advanced — which is why X-rays at routine checkups catch many failing fillings before symptoms appear.
What replacement usually involves
In most cases, replacing a filling is a straightforward, single-visit procedure — the old filling and any new decay are removed, and a fresh filling is placed. If decay has progressed significantly beneath the old filling, a crown may be recommended instead to fully protect the tooth going forward.
If it's been over five years since a filling was placed, or you've noticed any of these signs, it's worth a look at your next cleaning — replacing a filling early is almost always simpler than treating the problem it can lead to.
If it's been a while since your last check, our restorative care page covers what a replacement visit involves.
