Root canal treatment: Complications, Problems, Failures.
While it is possible that the root canal therapy your tooth has received will last you lifetime, complications, and even outright treatment failures, can occur. This page describes why and when these types of problems might occur.
What can cause root canal treatment to fail?
While the specific issues and factors involved with any one case might be quite involved, for the most part, when endodontic therapy fails its because aspects of the underlying basic goals of endodontic therapy have either not been achieved, or else have not been maintained.
What is the dentist trying to accomplish with their work?
In brief, when a dentist performs root canal therapy, this is what they are trying to do.
- Remove contaminates from within the tooth.
- Fill in and seal off the nerve space inside the tooth so no contaminates can seep in or seep out.
If, after a person's treatment has been completed, the tooth still harbors contaminates (that can seep out), or if new ones find a way to seep into the tooth (and then leach out), the tissues surrounding the root will be persistently inflamed. The treatment will not have been successful.
How can you tell you have a problem?
Some of the signs of failing root canal treatment can include: 1) Tooth pain, ranging from very mild to extreme. 2) Gum tenderness or swelling in the area near the tooth, ranging from very slight to quite pronounced.
These signs can either:
- Persist from the time of the root canal treatment.
- Be transient (vary week to week, or month to month).
- Show up suddenly, even though the tooth has been without symptoms for years.
Not all treatment failures are obvious to the patient.
There can be cases where a tooth has been, and continues to be, without symptoms but a dentist's x-ray examination identifies the problem.
What can cause root canal failure?
Having a problem with a tooth that's had root canal therapy simply indicates that either: 1) The cleaning aspect of the tooth's treatment was incomplete or ineffectual. 2) The seal that was created has not been successful in keeping contaminates from seeping in or out of the tooth. (Either it was deficient initially, or else has since deteriorated.)
Here are some examples of how these problems may come about.
- Root canals can fork, and these branches can be very minute and hard to detect and access. Because of this, one canal branch may be cleansed and sealed while the other is overlooked.
- A tooth may have more canals than expected. And in these cases, and especially when the unexpected canals are very tiny, the dentist may not discover them. If not, they will remain untreated.
- The tooth's root has cracked. - Cracks really can't be treated, in the sense that they can't be cleaned and sealed.
At the time of treatment, the dentist may not have been aware of the crack (in some cases they can be impossible to identify) or underestimated its significance. In other cases, the crack formed after the tooth received its treatment. - Due to a defective or inadequate dental restoration, contaminates have been able to reenter the tooth. This phenomenon is termed "coronal leakage." [ More about coronal leakage and how it can cause of root canal treatment failure. ]
- Even though a tooth has been expertly cleaned and sealed, over time the integrity of the seal can degrade, thus allowing recontamination.
What's the solution for failed root canal treatment?
With the exception of the cracked tooth scenario we described, all of the other problems mentioned above may possibly be resolved by retreating the tooth and then placing an appropriate final restoration.
Your dentist may offer to perform this treatment themselves, or they may feel that the expertise of an endodontist is needed. If retreatment is not a possibility (like with a cracked root) then the tooth should be extracted.
Other types of complications root canalled teeth may experience.
It is possible that your tooth's root canal treatment has been successful but the tooth itself has problems due to other factors and issues.
The tooth has broken or fractured.
Teeth that have had root canal treatment are seldom as structurally strong as they once were. And for this reasons, they often require the placement of a dental crown for strength and protection.
If an endodontically treated tooth does break, it's not always a big problem. Assuming that the damage is confined to just the crown portion of the tooth (not the root), it's quite likely that the tooth can be repaired. In many of these cases, the event simply acts as a wake-up call, in the sense that the person proceeds with having the dental crown that was always needed finally placed.
In instances where a very large portion of the tooth has broken off, the tooth may require a dental post and core before a new crown can be placed.
The tooth has extensive decay or gum disease.
Teeth that have had root canal treatment are not impervious to tooth decay and gum disease, both of which can lead to the loss of the tooth. You must brush and floss your teeth effectively so to prevent the occurrence of these problems.
