Root canal treatment failure: Coronal leakage.
In recent decades dentists have become increasingly aware of a phenomenon referred to as "coronal leakage."
This process involves the situation where oral bacteria and debris find a way to seep back into and recontaminate a tooth that has previously had root canal therapy.
Current thought is that coronal leakage probably plays a significant role in the failure of many endodontically treated teeth.
It's prevented by way of placing a proper, permanent dental restoration on a tooth promptly after its root canal treatment has been completed.
What is coronal leakage? - A description of the problem.
One of the goals of root canal therapy is the elimination of bacteria and other contaminates from within a tooth.
Now, imagine the situation where a tooth's treatment has been successful in accomplishing this task. But, over time, these same types of contaminates are able to seep back into the inner confines of the tooth.
If this type of recontamination is allowed to occur, the endodontic treatment that the tooth has received will fail.
That's exactly what coronal leakage is.
This recontamination process is precisely what the term "coronal leakage" refers to.
It's the phenomenon where oral debris and bacteria migrate from the mouth, past a tooth's dental restoration, and on into the tooth's treated root canal space.
The term "coronal" references the fact that the pathway of this seepage is via the "crown" portion of the tooth (the part of the tooth that lies above the gum line), as opposed to a pathway involving the root portion of the tooth (the portion of the tooth encased in the jawbone).
Coronal leakage can lead to root canal treatment failure.
Over the past several decades, coronal leakage has increasingly been hypothesized as being a primary cause of endodontic failure.
Studies have shown that reinfection of a tooth's root canal space can occur quite rapidly, if the root-filling materials that have been placed are not adequately protected by way of placing a well-sealing dental restoration.
Understanding / Minimizing your risk.
A) Coronal leakage as it pertains to temporary dental restorations:
Once root canal treatment has been completed, the dentist will need to place some type of temporary dental restoration that can create a seal that protects the tooth's root-filling materials until that point in time when a permanent restoration can be placed.
The dental patient must understand the temporary nature of this restoration, and the time frame over which it can be expected to maintain its seal.
In most cases, the permanent restoration should be placed as soon as it is reasonably convenient to do so. (In other words, don't drag your feet on scheduling this.) Leakage past a temporary filling is one of the major causes of coronal leakage.
B) Coronal leakage as it pertains to permanent dental restorations:
A dental restoration that can prevent coronal leakage will need to:
- Be one that is capable of creating a barrier to seepage.
- Be durable enough that this seal can be maintained, even as the tooth functions under extreme conditions.
- Offer protection for the tooth so the seal is not compromised due to tooth fracture.
After evaluating all factors, the dentist will make their treatment recommendation as to what type of restoration will do.
For some teeth a dental filling may suffice. In other cases, a dental crown may be required.
We discuss factors related to this decision in greater detail here: Rebuilding teeth after root canal treatment.