Irreversible pulpitis
Deep decay or a crack has irritated the pulp beyond recovery. The pain lingers after hot or cold, builds at night, and a root canal is the conservative way to save the tooth.
My Tooth Pain Won’t Go Away
Tooth pain that lasts more than 48 hours, gets worse at night, or returns after a recent dental visit usually means the pulp inside the tooth is inflamed or infected. The pain will not resolve on its own — but a microscope-guided exam plus CBCT 3D imaging usually finds the source in a single visit, and treatment is more predictable the earlier it starts.
Medically reviewed by Dr. Hope Feldman · Diplomate, American Board of Endodontics
Last reviewed May 5, 2026 · NPI 1275089088
The five common causes
Cracked tooth syndrome
A hairline fracture flexes when you bite, sending sharp pain through the tooth. CBCT 3D imaging plus microscope inspection diagnose it. Treatment ranges from a crown alone to root canal + crown to extraction depending on crack depth.
Apical periodontitis (infection at the root tip)
A previously dying pulp has spread infection into the bone around the root. May be visible as a pimple-like bump on the gums. Root canal therapy or retreatment resolves it.
Failed previous root canal
A root canal done years ago has reinfected, often because of a missed canal, a fractured crown, or new decay. Endodontic retreatment is the next step.
Referred pain
The tooth that hurts may not be the source. Pain from a sinus infection, a TMJ problem, or another tooth in the same nerve branch can feel like the wrong tooth. A specialty exam isolates the actual source.
Call us today if you have any of these
- Pain that wakes you up at night
- Pain that lasts more than 30 seconds after hot or cold
- Sharp pain when biting on a specific tooth
- A pimple-like bump on the gums near the painful tooth
- Visible facial swelling or fever along with the pain
- A tooth that has darkened compared to its neighbors
- Pain that returned after a recent filling or other dental work
Severe swelling, fever, or trouble swallowing is a same-day emergency — call (480) 943-1900 or proceed to the nearest ER.
Frequently Asked Questions
- My tooth pain won't go away — what does it mean?
- Tooth pain that lasts more than 48 hours, gets worse instead of better, or wakes you up at night usually signals a pulp problem (the nerve inside the tooth). The pulp may be inflamed (reversible), inflamed beyond recovery (irreversible pulpitis, which needs a root canal), or already dying. Sharp pain that lingers after a cold drink for more than 30 seconds is a classic sign.
- Why won't my tooth stop hurting?
- Persistent tooth pain is almost always one of four things: deep decay reaching the pulp, a hairline crack reaching the pulp, infection in or around the root tip, or referred pain from a different tooth or sinus. Pinpointing the source requires a microscope-guided exam plus CBCT 3D imaging — guesswork wastes time and money.
- Why does my tooth hurt at night more than during the day?
- Lying flat increases blood pressure to the head, which increases pressure inside an inflamed pulp chamber. Daytime distractions also mute the pain. Night-worsening tooth pain is a classic sign of irreversible pulpitis — the pulp tissue is no longer healthy and a root canal is the conservative way to save the tooth.
- Can a tooth pain go away on its own without treatment?
- Mild sensitivity from a recent filling or a temporary inflammation can settle on its own in a few days. True pulp infection cannot. If pain persists more than 48 hours, returns repeatedly, or progresses to swelling or fever, it will not heal without intervention. Ignoring it allows the infection to spread to the surrounding bone.
- How urgent is persistent tooth pain?
- Pain alone is uncomfortable; pain plus swelling, fever, or trouble swallowing is a same-day emergency — call (480) 943-1900 immediately. Pain alone without those signs warrants an appointment within a few days. The earlier you are evaluated, the more conservative and predictable treatment is.
- What if my dentist says the tooth looks fine on X-ray?
- Standard 2D X-rays miss a substantial fraction of pulp problems and most hairline cracks. A specialist visit with a microscope-guided exam plus CBCT 3D imaging routinely finds what 2D imaging missed. Persistent unexplained pain on a tooth that "looks fine" is a high-yield reason for a second-opinion visit.
Related: Signs you need a root canal · Cracked tooth diagnosis · Emergency endodontist
Don’t wait it out
We hold time daily for urgent endodontic visits. Most patients are seen the same or next day.