Will a tooth's crown still be usable after its root canal treatment has been completed?

There can be instances where teeth that have previously had a dental crown placed will require root canal treatment. In fact, this is a relatively common occurrence.

In order for the root canal therapy to be performed, the treating dentist will need to access the inner aspect of the tooth. To do so they will need to drill a hole (make an "access cavity") through the tooth's chewing surface that extends to the tooth's pulp chamber.

In this type of situation the patient may wonder what will become of their dental crown. Will it be damaged? Will it need to be replaced? Of course every person's situation will be different, so it will be up to your dentist or endodontist to advise you about the specifics of your case but, in general, here are the various outcomes that are possible.

A) It may be possible that your dentist will remove the dental crown prior to performing the root canal therapy.

Removing a tooth's dental crown before its root canal treatment is performed can be an excellent plan. The idea would be to remove the crown, perform the endodontic therapy and then recement the crown. The tooth would receive its needed treatment and no hole would need to be drilled through the crown.

As ideal as this plan sounds in theory, the practical application of this approach can be taxing both for the dentist and dental patient alike. Dental crowns can be exceedingly difficult to remove. Even in those cases where a crown can be removed it is quite possible that the crown will be damaged. In the worst of cases, the tooth also might be damaged, even significantly so. Bottom line, a dentist may try to remove a patient's crown before performing root canal treatment but if it doesn't come off easily they will probably back off on this approach promptly.

B) The dentist will create the root canal treatment access cavity right through the surface of the crown.

It is commonplace that a dentist will determine that a dental crown will not be easily removed and they therefore must go ahead and create the needed access cavity right through the crown. The degree to which this act will damage the crown will vary. It will depend both on the size of the hole that is created and the type of material from which the crown has been made.

In the case of a metal (gold) or porcelain-fused-to-metal dental crown, the act of perforating the crown may not weaken it significantly. In the latter case, however, the act of drilling may cause some of the porcelain that has been applied to the crown's surface to fracture off. In the case of an all-ceramic (all-porcelain) crown, the act of creating an access hole may very well weaken the integrity of the crown substantially.