How to Tell If Your Root Canal Has Failed (and What to Do Next)

Sometimes patients ask: What happens if a root canal fails? The good news is that around 95% of all root canals are successful and last for years — often a lifetime.

However, in medicine, as in life, there are no guarantees. If you’re experiencing severe pain in a tooth that previously had a root canal, there’s a chance the treatment has failed and retreatment may be necessary. This post will help you understand why root canals can fail, how to recognize the signs, and what treatment options are available.

Note: This blog post is not a substitute for professional dental care. Every patient and every tooth is unique. Seeing an experienced endodontist who uses advanced diagnostic tools gives you the best chance of successful retreatment.

What is a Failed Root Canal?

First, let’s reassure you: most root canals work exactly as intended and bring relief from pain. But occasionally, a root canal may not fully resolve the infection.

A failed root canal occurs when an infection remains or reappears at the root of a previously treated tooth. According to the American Association of Endodontists, here are common causes:

• Complicated root anatomy: Teeth may have tiny branches in their root canals that can be difficult to locate and treat.
  
• Curved or narrow canals that weren’t completely cleaned during the first procedure.
  
• Cracks or fractures in the tooth that allow bacteria to re-enter.
  
• Delays in placing a permanent crown or final restoration after the root canal.
  
• New decay that exposes the treated root to bacteria.

Whatever the cause, identifying the issue starts with a thorough examination. At Ballantyne Endodontics, we believe every tooth has its own story — and it deserves a customized treatment plan.

Signs Your Root Canal May Have Failed

If a root canal fails, you may feel discomfort that is either persistent or returns after a period of relief. Acting quickly is important: untreated infection can spread and affect surrounding teeth or even overall health.

Here are some symptoms to watch for:

• Ongoing or severe pain in the treated tooth, especially after the initial tenderness should have subsided.
  
• Swelling around the gums or jaw, which may indicate infection.
  
• Pus or bloody discharge, often a sign of an abscess.
  
• Sensitivity to pressure or temperature that lingers longer than normal.
  

If you’re experiencing these symptoms, don’t wait. Call your dentist or endodontist promptly. The sooner you receive appropriate care, the better your chances of preserving your natural tooth and avoiding complications.

Treatment Options for a Failed Root Canal

If you’re dealing with a failed root canal, don’t worry — retreatment is often possible and effective.

Treatment options may include:

• Non-surgical Retreatment (a second root canal)
  
• Surgical Intervention (such as an apicoectomy)
  
• Tooth Extraction, when necessary

At Ballantyne Endodontics, our goal is always to save your natural tooth whenever possible. Thanks to advances in dental technology, many root canal retreatments are more successful today than they were in the past. If your original procedure was done years ago, newer tools and techniques — including 3D imaging and enhanced magnification — can often reveal previously missed problems and improve outcomes.

What Happens During Root Canal Retreatment?

In many cases, retreatment is the best choice. Here’s what to expect:

1. Advanced diagnostics: Your endodontist will likely start with a Cone-Beam CT scan, which offers a 3D view of your tooth’s internal structure. This helps reveal hidden canals, fractures, or other complications.
   
2. Accessing the tooth: Your provider will gently reopen the tooth to remove the previous root canal material. This may involve removing a crown or filling.
   
3. Cleaning and reshaping the canals: Using high-powered magnification and lighting, your endodontist will clean and disinfect the root canal system more thoroughly.
   
4. Filling and sealing: Once clean, the canals are refilled and sealed to prevent future infection. A temporary filling may be placed until your permanent crown is ready.
   
5. Restoration: You’ll likely return to your general dentist for a new crown or other restoration to protect the tooth and restore full function.

Your dental team will walk you through each step of the process and provide instructions for recovery. Following through with all appointments and care guidelines is key to success.

Next Steps: Find a Qualified Endodontist

We hope this article answered your questions about what happens if a root canal fails. If you’re experiencing pain or symptoms after a previous root canal, it’s important to see an experienced endodontist.

At Ballantyne Endodontics in Charlotte, NC, we’ve helped thousands of patients preserve their natural teeth through advanced retreatment and surgical care. Dr. Sonia Chopra, D.D.S., our founder, understands the patient’s perspective — she once needed a retreatment herself and has made it her mission to deliver compassionate, expert care.

Call us today to request a referral or schedule a consultation. We’re here to help you restore your comfort, confidence, and long-term oral health.