1. Existing crack or fracture in tooth, especially if it's a vertical one
2. Missed canal
3. Recurring, persistent infection
4. Incomplete root canal filling
Best thing to do is see your dentist or endodontist about this.
Some teeth following a root canal can have lingering pain anywhere from a few days to 6-8 months following the procedure. This can be part of the healing process and often resolves by itself.
Other reasons can include infected nerve tissue inside the tooth that was not removed. Either it couldn’t be removed (may depend on the tooth and the anatomy of the tooth) or the diseased tissue was just missed. There are few teeth that this is more likely to happen to so again, I can’t really comment specifically in your case.
More reasons: the tooth may have fractured. The great majority of teeth that have had a root canal procedure, need to have a cap (crown) placed because these teeth become dried out and brittle. As such, they are susceptible to breaking which can lead to pain. As part of that, your bite needs to be adjusted properly so that you are not chewing too hard on the tooth.
And finally, in a very small percentage of patients, the procedure does not solve the initial problem. No dental or medical procedure works 100% of the time for 100% of the people.
If you have not already had the dentist who did the procedure reevaluate the tooth, I would suggest you do so.
Hope this helps. Keep smiling,
David M. Kaffey, DDS
socket. This can lead to pain as well. Referred pain from a different tooth is another option which can cause pain.
On a treated canal, it may have over treated into the periapical space (area beyond the tooth tip.)
Tooth maybe cracked or fractured. Go back to your dentist.
Other common reasons are small fractures in the root