Can a Root Canal Fail?
Key Takeaways:
Understanding Root Canal Failure:
Although root canal failure is relatively rare, we must understand its implications. Failure can result from either incomplete removal of infectious material during treatment, or newly infected teeth post-treatment; being aware of signs such as persistent pain or swelling is key in timely intervention.
Causes of Root Canal Failure:
Many factors can contribute to root canal failure, including intricate tooth structures, new decay, loose fillings or crowns, or cracks in treated teeth that cannot be controlled by endodontists; though awareness of such potential sources of failure will help patients understand why ongoing care and maintenance are so essential for optimal oral health.
Endodontic Retreatment:
When faced with root canal failure, endodontic retreatment becomes essential to saving the tooth. Endodontists specialize in performing retreatment procedures which include cleaning and sanitizing the interior of the tooth before resealing and filling for successful outcomes despite initial failure; their high success rate underscores the significance of seeking professional advice and adhering to post-treatment instructions for optimal outcomes.
A common question our patients ask is, “Can a root canal fail?” While the answer is yes, you need to understand more about root canals, why they fail, and how to reduce your risk of root canal failure. We’ll break the myths and help you understand the facts behind root canal therapy so you feel more comfortable when you get your procedure.
Root canals are generally effective in treating infected or damaged teeth, with success rates typically between 86% and 98%. However, there are instances where a root canal may fail, and understanding the reasons for this can help patients make informed decisions about their treatment options.m
What Is a Root Canal Failure?
Root canal failure is very rare. The success rate of this procedure ranges from 82.0% based on a strict definition to 92.6% using a loose definition of failure. Per the study, the loose and strict definitions for success came from X-ray images taken after the root canal. The strict definition requires no signs of inflammation to be a success. The looser definition allows an area of inflammation to show signs of shrinkage after a root canal to indicate a successful treatment.
Failure of a root canal means some infectious material remains in the tooth after the procedure, or the tooth becomes newly infected after the treatment. This bacteria can trigger new inflammation and infection in the tooth, causing pain when you should start to feel better.
Why Do Root Canals Fail?
Despite the high success rate of root canals, failures can occur for several reasons, some of which fall outside the skills of the endodontist.
Occasionally, teeth can have highly intricate passages that the doctor cannot access or find during a standard root canal. If any bacteria remains, even in inaccessible places inside the tooth, the root canal can fail.
Other common causes of root canal failure can happen after the procedure and include:
Incomplete Cleaning of Canals: One of the main reasons for root canal failure is the incomplete removal of bacteria or infected tissue inside the tooth’s root system. The tooth’s canals can be intricate, with tiny branches that may be missed during the initial cleaning. If any infection remains, it can spread, causing symptoms to recur.
Complex Tooth Anatomy: Some teeth have a complex internal structure that can be difficult to clean thoroughly. For instance, molars often have multiple roots with intricate canals, some of which might be overlooked. These hidden canals can harbor bacteria, leading to persistent infections even after the procedure.
New Decay or Infection: After a root canal, the treated tooth is often restored with a filling or crown. If these restorations fail—due to wear, damage, or improper fit—the tooth can become vulnerable to new decay. Bacteria can infiltrate the tooth through cracks or loose fillings, causing a new infection.
Fractured or Cracked Tooth: The tooth’s structure can weaken after a root canal, making it more prone to fractures or cracks. If the tooth breaks, bacteria can easily enter the tooth’s internal structure, leading to reinfection. Patients should avoid putting too much pressure on a recently treated tooth until it’s fully restored with a crown.
Improper Sealing: Proper sealing of the tooth after a root canal is essential to keep bacteria out. If the seal is not tight, bacteria can penetrate the tooth and reinfect the canal, necessitating retreatment.
Common Signs of a Failed Root Canal
Over time, a tooth with a failed root canal will show symptoms that something is wrong. If the treatment itself fails, you may notice new pain or pain that doesn’t start to lessen after two or three days. Talk to your endodontist about any concerning symptoms you have during recovery from your initial root canal.
A root canal can also experience failure long after the treatment. Decay or new damage to the tooth can allow bacteria to get inside, requiring retreatment. Watch out for the following symptoms to indicate a root canal failure in a treated tooth:
- Persistent pain: Ongoing pain in the treated tooth is a common sign of failure. This pain may occur spontaneously or when biting down.
- Swelling: Swelling around the treated tooth or in the gums can indicate an underlying infection.
- Sensitivity: Sensitivity to hot or cold foods and beverages can signal that the infection is still present.
- Tenderness: Tenderness in the jaw or surrounding tissue may also indicate that the root canal was unsuccessful.
Whenever you notice any of the above signs, you should call an endodontist for an exam and possible retreatment of the tooth.
Treatment Options for Failed Root Canals
If a root canal fails, endodontic retreatment is often the best course of action. In this procedure, the dentist or endodontist will reopen the tooth, remove the old filling material, thoroughly clean the canal system again, and place a new filling. This may resolve the issue if the failure was due to incomplete cleaning or sealing.
In cases where retreatment is not effective, or if the structure of the tooth is compromised, a surgical procedure called an apicoectomy may be necessary. This involves removing the tip of the tooth’s root to eliminate the infection. In rare cases, tooth extraction may be the only option, particularly if the disease is severe or if the tooth is too damaged to save.
Who to See for Endodontic Retreatment
While some dentists perform root canals, they will not do endodontic retreatment. No matter where you went for your root canal, you need to see an endodontist for retreatment. Endodontists have the training and tools needed to see whether retreatment or surgery is a better option. They also have the necessary knowledge and skills needed to retreat a formerly endodontically treated tooth or perform apicoectomy surgery as needed.
Endodontic Retreatment Process
Endodontic retreatment is non-surgical and uses a local anesthetic. Therefore, you can drive yourself back home to work or school after your appointment.
The process of this retreatment includes the following steps, which the endodontist adapts to your dental needs:
- Prepare your mouth for the procedure by placing a dental dam to isolate the tooth and numbing the treated area.
- Remove the dental work on the tooth, including the filling from the original root canal.
- Examine the canals inside the tooth to find areas the first treatment missed.
- Clean and sanitize the inside of the tooth to remove any infection from the tooth.
- Reseal and fill the tooth.
You may need to get a new crown on the tooth if you need one after the first root canal. Your dentist can fit you with a new crown if you need one. Make sure to keep all follow-up appointments your endodontist or dentist requests after your retreatment.
Retreatment Success
Root canals rarely fail, but if you do need retreatment in a tooth, rest assured that the process will likely save the tooth. Endodontic retreatment has a high success rate of 90.4% after two years, according to a study supported by the American Association of Endodontists Foundation.
How to Raise the Chances of Root Canal or Retreatment Success
To prevent root canal failure, it’s important to follow your dentist’s post-procedure care instructions. This includes practicing good oral hygiene, attending regular dental check-ups, and ensuring that any crowns or fillings are well-maintained. Avoiding excessive pressure on the treated tooth, especially before it has been fully restored, can also help prevent fractures or damage that might lead to reinfection.
Follow Your Doctor’s Instructions
First, follow your endodontist’s requirements about follow-up care and getting a crown or other dental work to protect the tooth. Waiting too long raises the chances of the tooth sustaining damage before it gets a reinforcing crown.
Take Care of All Your Teeth
Second, practice excellent oral hygiene for all your teeth, including your treated tooth. Brush and floss twice daily and see your dentist two times a year. Regular dental care to prevent cavities also helps protect endodontically treated teeth from new decay.
Protect the Treated Tooth
Finally, use caution when using the tooth to avoid damaging the crown or filling over it. Don’t bite down with that tooth on hard foods, and wear a mouthguard to keep all your teeth protected when playing contact sports. These habits will reduce the chances of cracking a treated tooth.
While you cannot stop all causes of needing retreatment, you can do the above to raise the chances that your root canal or retreatment will last for life.
Don’t Let a Failed Root Canal Cost Your Tooth
While root canal therapy is highly effective in most cases, failures can occur. Understanding the causes and recognizing the signs of failure can help patients seek timely treatment. With proper care and retreatment, it’s often possible to preserve the tooth and avoid more invasive procedures.
If you notice any symptoms of a failed root canal, even years later, you should consider endodontic retreatment to prevent tooth loss. Contact us at your closest Southwest Endodontics (Geneva or Orland Park) for an examination to determine if retreatment is necessary. We offer painless and compassionate endodontic care every day to save your teeth.