Seven Signs You May Need Root Canal Treatment

Not every toothache means the nerve inside the tooth is in trouble. Sensitivity after a new filling, a bit of gum recession or a high bite can all cause discomfort that settles on its own. But certain patterns of pain are typical of an inflamed or infected pulp — the soft tissue inside the tooth — and those teeth rarely get better without treatment.

Here are the signs we see most often in patients who go on to need root canal treatment.

1. Sensitivity to hot or cold that lingers

A healthy tooth may twinge briefly when you drink something cold, but the feeling disappears within a second or two. When the pulp is inflamed, the pain hangs around: thirty seconds, a minute, sometimes longer. Pain that is triggered by heat and relieved by cold is a particularly strong sign that the pulp is dying.

2. Pain on biting or chewing

Pain when you bite down, or when you release the bite, can mean that inflammation has spread from the pulp to the ligament around the root. It can also be a sign of a cracked tooth, which is why we test individual cusps rather than the whole tooth at once.

3. Spontaneous or night-time toothache

Pain that starts by itself — without a trigger — or that wakes you at night is a classic sign of irreversible pulpitis. Lying down increases blood pressure in the head, and the swollen pulp, trapped inside the rigid tooth, has nowhere to expand. Pain that keeps you awake should be assessed promptly.

4. Swelling or a "pimple" on the gum

When the pulp has died and infection reaches the bone, the body may drain the infection through a small sinus tract on the gum next to the tooth. It often looks like a small spot that comes and goes and may leave a bad taste. Larger swelling of the face or jaw needs same-day attention.

5. A tooth that has darkened

A front tooth that turns grey or yellow-brown months or years after a knock has usually lost its blood supply. The tooth may not hurt at all, but the dead pulp tissue can become infected over time. After dental trauma, teeth should be monitored for exactly this reason.

6. Pain that is hard to locate

Pulp pain is poorly localised in its early stages. Patients often describe an ache across several teeth, or even confusion between the upper and lower jaw on the same side. Careful testing under magnification usually identifies the culprit.

7. A deep filling, crack or previous dental work

Teeth with large fillings, crowns or repeated treatment are more likely to develop pulp problems, sometimes without warning. If one of these teeth starts to feel different, it is worth having it checked rather than waiting.

What if there are no symptoms at all?

Some infected teeth cause no pain. They are picked up on routine radiographs, where a dark area around the root tip shows that the bone has been affected. These teeth still need treatment: the infection will not resolve by itself and can flare up unpredictably.

What to do next

If you recognise any of these signs, see your dentist or contact us for an assessment. Early treatment is simpler, more comfortable and gives the tooth the best chance of being kept. And if the tooth turns out not to need a root canal, you will have the reassurance of knowing why it hurts.