Still hurting after the root canal? The short answer.

This is the short letter, for the person searching at midnight. Your tooth had a root canal and it still hurts. Three questions sort out what's happening — and only one of the answers is bad news.

Question one: how long ago?

Days ago? Normal. The ligament around the root is healing — the tooth’s roots are still in place, anchored in your jawbone and surrounded by living tissue that can sense pressure, temperature, and inflammation. Two or three days of fading soreness is textbook. About 40–60% of patients feel some discomfort in the first week. Weeks-to-months ago, or pain that faded and came back? Keep reading.

Question two: what kind of pain?

Bite tenderness that’s fading — healing. A bite that feels “high” — a two-minute adjustment; call. Hot or cold sensitivity in the treated tooth — that shouldn’t be possible with the nerve gone, and usually means a missed canal or a neighboring tooth; call. Throbbing, swelling, or a gum pimple — infection persisting or returning; call today.

Question three: is it getting better or worse?

The trend is the diagnosis. Better each day: healing — finish the recovery. Worse, or returning after quiet months: something needs looking at — most often a missed canal (upper molars have an MB2 canal missed in up to 40% of cases treated without a microscope), a leak under the crown, or occasionally a crack. All findable on a CBCT; most fixable with retreatment.

An important note: up to 50% of persistent post-root-canal pain cases turn out to be nonodontogenic — the pain isn’t coming from the tooth at all. TMJ disorders, sinus inflammation, and nerve conditions can mimic dental pain convincingly enough to fool both patients and general dentists. This is why we investigate why it hurts before recommending any treatment.

For the complete clinical picture, the long version of this letter is Letter No. 22.