What does this mean?
A filling or crown protects the tooth, but the tooth itself carries on living beneath that covering. A small gap at the edge can allow decay to start again underneath, or the nerve of the tooth to become irritated, and this often advances for months without any pain.
The timing of the pain is a clue. Pain only on biting often suggests a filling that has been left high, or a crack in the tooth. Pain with cold or heat that lingers suggests the nerve is struggling, and pain that comes on its own, especially at night, can show that inflammation is advancing.
When the gum recedes, the edge of the crown and the root surface beneath it are exposed. Unlike enamel, that area decays easily and is sensitive, so the cause of the pain is sometimes the recession itself. An examination and an X-ray show which it is.
Four causes are common behind pain under a filling or crown, and what triggers the pain and how long it lasts separate them.
Likely causes
What helps at home?
- Avoid hard food and very cold or hot food on that side for a while
- Note whether the pain comes on biting, with cold or on its own; that information is valuable to the dentist
- Do not test the tooth by biting on it, and do not try to move the crown with your hand
- Clean the tooth and the gum edge with a soft brush, without forcing the area
- Pain that wakes you at night or comes on by itself
- Swelling, a bump or a bad taste around the tooth
- A crown that moves or comes off
- Pain that starts with heat and does not fade for a long time
Frequently asked questions
- Why is a tooth that has been filled hurting again?
- The most common cause is decay starting again at the edge of the filling. A high filling, a crack in the tooth or an irritated nerve can give the same complaint. An examination and an X-ray decide which.
- Can decay develop under a crown?
- Yes. If there is a gap at the edge of the crown, or the gum has receded, the tooth surface underneath can decay. Because it lies under the crown it cannot be seen from outside, and it is often picked up on an X-ray.
- How long does pain last after a crown is fitted?
- A few days of mild tenderness are possible after a crown is fitted, and it eases once the bite is adjusted. Clear pain on biting, or sensitivity that grows over days, means the height of the crown or the state of the tooth should be checked.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.