Root canal work is a common procedure performed on adult teeth. New technologies and anaesthetics help to ensure that a root canal procedure is as comfortable as possible. The treatment is usually very effective but on a rare occasion, it may fail.
Reasons for failure:
– An error by the dentist
– Erosion of the tooth or sealant over time
– An additional canal in the tooth not spotted by the dentist
– An obstruction that caused incomplete cleaning of the canal
– Vertical cracks in the tooth
– Leakage in the restoration
– Poor dental hygiene
People who experience severe continuous pain should report it to the endodontist for further evaluation.
Read more about root canals in general here https://www.medicalnewstoday.com/articles/320978.php