Endodontics
Root canal retreatment
Repeating root canal treatment when a tooth does not heal or becomes infected again.
Purpose
Save the tooth again
Visits
One or two
Anaesthetic
Local
Alternative
Surgery or removal
Overview
Sometimes a root-treated tooth stays sore or becomes infected again, perhaps because a canal was hard to clean or a new problem developed. Retreatment reopens the tooth to clean and seal it once more.
The old filling material is removed, the canals are cleaned again and resealed. It is a careful procedure that can give the tooth another chance before considering surgery or removal.
What to know
- A second attempt to save a root-treated tooth
- Used when symptoms or infection return
- The old root filling is removed and replaced
- An alternative to losing the tooth
Common questions
Why did the first treatment not work?
Causes include hidden canals, a missed crack, leakage or new decay.
Is retreatment harder than the first time?
It can take longer, as the previous filling must be removed first.
What if retreatment is not possible?
Minor surgery, called an apicoectomy, or removing the tooth may be considered.
Will I need a new crown?
Often the existing crown is removed, so a new restoration may be needed.
What are the chances of success?
Many teeth settle well, though success is generally a little lower than first-time treatment.
Related topics
Root canal treatment
Treatment that saves a tooth by removing infected or damaged tissue inside it.
Apicoectomy (surgical endodontics)
Minor surgery to remove infection from the tip of a tooth's root.
Dental crown
A custom cap that covers and protects a damaged or weakened tooth.
Cracked tooth & the nerve
How a cracked tooth can irritate the nerve and what can be done about it.
Dr Rick Iskandar · Reviewed June 2026