Why does my tooth hurt when I bite down?
Short answer: Pain only on biting usually means one of three things: a crack in the tooth, a filling or crown sitting fractionally too high, or inflammation in the ligament around the root tip. A sharp pain on releasing the bite points strongly to a crack. All three need examining; none improve on their own.
The three usual causes
A cracked tooth
The classic sign is not pain when you press down — it is a sharp jolt when you let go. Biting closes the crack; releasing lets it flex open and the pain fires. If that description matches, say exactly that when you book; it is genuinely diagnostic.
Cracks often do not show on x-rays, which is why the story you give matters so much.
A filling or crown that is too high
If it started immediately after dental work, this is the likely answer. A restoration a fraction of a millimetre too tall takes the full force of your bite before the other teeth meet, and the ligament around it becomes bruised.
The fix takes minutes — a small adjustment to the biting surface. It is a routine correction, not a complaint, and there is no reason to endure it.
Inflammation at the root tip
If the nerve inside the tooth has died, inflammation gathers at the tip of the root, and the tooth becomes tender to pressure from above. Often there is a history of a deep filling, a knock, or previous severe toothache that stopped.
What the timing tells you
- Pain on release → suspect a crack
- Started right after dental work → suspect a high restoration; easily fixed
- Tender to touch or tapping, constant ache building → suspect the root tip
- Pain plus swelling → read this now; infection may be spreading
What to do meanwhile
Chew on the other side — repeatedly testing the sore tooth propagates a crack. Avoid very hard foods on that side entirely. Ordinary painkillers taken as directed are reasonable short term.
Book within the week. A cracked tooth caught early can often be saved with a crown; the same crack left to spread can end with the tooth splitting to the root, at which point the options narrow considerably.
Common questions
Why does my tooth hurt only when I chew?
Because the pain is triggered by pressure or by flexing rather than by temperature. That points to a crack, a restoration sitting too high, or inflammation in the ligament at the root tip.
What does it mean if it hurts when I release the bite?
That specific pattern — pain on release rather than on pressing — is the classic sign of a cracked tooth. Biting closes the crack; releasing lets it flex apart.
My tooth hurts after a new filling. Is that normal?
Mild sensitivity for a few days is normal. Pain specifically on biting usually means the filling is fractionally too high and needs a small adjustment. That takes minutes and you should go back and have it done.
Can a cracked tooth be saved?
Often, if it is caught before the crack spreads. A crown that holds the tooth together is the usual answer. A crack that reaches the root is much harder to treat and may mean losing the tooth.