Root canal treatment complications: Coronal leakage -

What is it? / What are the consequences? / How is it prevented? / Treatment solutions. - Details and selected videos explaining this subject.

What is coronal leakage?

Coronal leakage refers to a phenomenon where bacteria and other contaminates find a way to seep from a persons oral environment (mouth), past their tooth's dental restoration and into the interior of a tooth that has previously had root canal treatment.

Why is that a problem?

This returns the tooth to a diseased state. One where debris and bacteria have colonized the tooth's interior "nerve space." And as a result, irritants can leak out of the tooth's roots and cause persistent irritation (inflammation) of the tissues that surround it. (More details & video.)

The possibility of this phenomenon means that the long-term success of any tooth's root canal therapy depends as much on the integrity of the restoration that's placed after its work has been completed as it does on the endodontic treatment itself.

How is coronal leakage prevented?

This scenario is prevented (or at least its chances of occurring minimized) by way of the type of restoration that's placed after the tooth's root canal treatment has been completed.

The restoration must:

  • Create a substantial barrier to any contaminates that might seep from the oral cavity into the tooth.
  • Be a type of restoration that's durable enough that it can maintain this seal over the long term.
  • Be placed soon enough after the completion of the tooth's endodontic therapy that problems associated with leakage haven't already occurred.

What kind of restoration makes the best choice?

The different types of dental restorations that can meet the above needs will vary according to each tooth's particular situation.

Dental fillings:

In cases were the tooth:

  • Has experienced little structural damage in the past (decay, fracture).
  • Has only required a very conservative access cavity for its root canal work.
  • Isn't exposed to exceptionally heavy chewing forces (a situation more likely with front teeth).

Placing a dental filling may suffice.

Dental crowns:

In cases were the tooth:

  • Has experienced substantial structural damage in its past (decay, fracture).
  • Has required a sizable access cavity for its root canal work.
  • Is exposed to heavy chewing forces (the case that's likely with molars).

Placing a dental crown typically makes the superior choice. (Crowns in general are known for their ability to create a predictable and lasting seal.)

Of course, in all cases you'll simply have to rely on the advice of your dentist, after they have had a chance to evaluate your tooth's situation.

Placing the final restoration promptly.

You'll need to quiz your dentist about the time frame during which your tooth's permanent restoration should be placed.

At the completion of your tooth's root canal therapy, your dentist will probably just place a temporary filling. And over time this restoration and the seal it creates can be expected to deteriorate.

Your goal should be to have it replaced with a permanent restoration (filling or crown) long before the complication of coronal leakage is likely to become an issue.

What's the solution if coronal leakage has occurred?

Of course your dentist will need to evaluate your situation, but generally speaking if coronal leakage has occurred the only solution is to perform root canal treatment on the tooth again.

  • Due to the leakage, bacteria and contaminates are now once again present in the recesses of the tooth's root canal system (an unhealthy and unpredictable state).
  • The now contaminated filling material placed during the tooth's initial treatment must be removed and its canals cleaned again and then resealed.

It's likely that the only alternative treatment your dentist has to offer is extracting the tooth.

Videos about Coronal Leakage.

The following videos explain issues about this topic.

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Video: Dental coronal leakage.

 Watch Video Coronal Leakage

Running time: 2 minutes 35 seconds.   /   Type: Animation

What this video covers:

This video provides a general overview of the issue of coronal leakage. It includes these details:

When it comes to root canal, there are two seals that are important.

  • The process of performing endodontic therapy is used to clean out and then fill in and seal off the "nerve" space inside a tooth.
  • Then a second seal, which helps to protect the internal one, is created by the dental restoration that covers over or fills in the "access cavity" through which the root canal therapy was performed.

Coronal leakage involves the recontamination of the tooth's interior.

The tooth's second seal acts as a barrier to contaminates in the mouth that would otherwise seep into it.

In the case of coronal leakage, the restoration has failed in this task. Penetration into the tooth has occurred. As a result, it's root canal system is recontaminated with bacteria and debris.

The type of restoration placed is important in preventing coronal leakage.

Once a tooth's root canal treatment has been completed, the dentist must determine what type of dental restoration can best seal off and protect the tooth's work, as well has how soon this restoration should be placed.

It's possible that in some cases a dental filling might suffice. But in cases where a substantial portion of the tooth must be rebuilt, or the tooth must function under heavy chewing forces, placing a dental crown frequently makes the better choice.

 Watch Video What's the purpose of root canal treatment? - Part 2..

Run time of segment selected: 19 seconds.   /   Type: Animation

What this video covers:

The effects of contaminates leaking from a tooth's root canal system.

We've selected just a small segment of this video for viewing and are using it to illustrate how contaminates harbored inside a tooth (like those that exist after coronal leakage has occurred) can serve as a persistent source of irritation to the tissues that surround the tooth's roots.

As mentioned in the video, most of the time this irritation may exist as low-grade, mostly asymptomatic, chronic inflammation. But at times it may flare-up in the form of an acute tooth abscess (pain, swelling).

Either way, due to the fact that the coronal leakage has occurred the tooth's previous root canal treatment must now be considered a failure. Extraction or endodontic retreatment are the only two clinical choices.