Should a Root Canal Be Done with the Old Crown in Place??

My wife was recently told she needed a root canal after experiencing some pain under her old crown. The dentist also told her that after the root canal a new crown would be needed to replace the old one. After the root canal was done she went to have the new crown done but was told the existing tooth was to deteriorated for a crown. Is it normal for a root canal to be performed with the old crown in place? Thank you

Doctor Answers 9

It can, but I would not recommend it...

In most cases when a patient is experiencing pain where there is an "old" crown it is due to the tooth having decay under it.  The most common reason is because it is no longer properly sealed & bacteria is filtering in.  Other times the crown may be properly sealed & it is just reacting to the trauma caused by the actual preparation, which occasionally happens as well.  Every case is different & every dentist treats differently but I usually recommend taking the old crown off to properly evaluate & see if there is enough tooth structure to properly do a root canal, post & crown. Good Luck

Los Angeles Dentist
5.0 out of 5 stars 1 review

Root canal through a crown

A root canal can be done through an existing crown if the crown is in good condition, has closed margins (edges), and there is no decay underneath the old crown.  After the root canal treatment is completed, the hole in the crown will be patched up with a filling material.

However, if the crown needs to be replaced, then the crown will be removed, all decay will be cleaned off, and the root canal treatment will be done.  If insufficient tooth structure is left to support a crown, then a post will be necessary for the retention of a crown.  All the best, Dr. Elizabeth Jahanian

Elizabeth Jahanian, DDS
Los Angeles Dentist

A root canal can be done with an old crown in place but depends

This is quite common. Many teeth have crowns done due to fractures or cavities but no root canal was needed at the time if the nerve of the tooth was fine. However, sometimes a few years down the tooth may act up needed the root canal to be done after the crown. If the crown is intact and has no filtrations or leakage (cavities around the margin) then you can do a root canal and keep the crown. You just do a filling throught the top where the root canal was done.

However, if the old crown has cavities or poor margins, then a new crown will be needed and you must first assess if there is sufficient tooth structure to make a new crown. This means you should remove the old crown the see what is there before the root canal.  A clinical exam and x-ray should tell you if the crown is leaking or has cavities.

Hope this helps

Dr. T

Mauricio C. Tijerino, DMD
Miami Beach Dentist

Root Canal with Old Crown in place

It is non  uncommon to perform a root canal treatment with  a sound old crown in place by making an access opening through crown and patching it after the root canal is completed. The dentist should examine the tooth carefully with x-rays and eyes to determine if the old crown is adequate.

Mickey Bernstein, DDS
Memphis Dentist
5.0 out of 5 stars 1 review

Normal Protocol For A Root Canal

Root canals are needed because of pain or infection/ abcess.  There are many reasons why one would need to do a root canal and many times they are done through the exsisting crown.  If it is an old crown, chances are you need a new crown because there is decay.  Unfortunately, we assume there is room for a new crown but don't always know until the old crown has been redone.  If there is a question about how sound the old crown and tooth are, many times we take off the crown before the root canal to check -It has a lot to do with what the dentist sees.  Nothing is ever a guarantee but we do try to educate as much as possible before beginning any treatment.

Wendy S. Spektor, DDS
Bellevue Dentist
5.0 out of 5 stars 3 reviews

Root canals through crowns

Root canals are commonly done through old crowns if significant decay is not seen on the xray in order to divide treatment into stages for economic or time reasons.  However,  if significant decay is found to be present, the crown should be removed to eliminate decay first and make sure the tooth is savable.  Also so that the decay won't progress too far, if the a new crown is not to be done soon, it would be wise to remove the old crown and all the decay, otherwise the tooth might continue to decay and  be lost despite the root canals presence.  Talk to your dentist about options at this point.

Scott LeSueur, DDS
Mesa Dentist
5.0 out of 5 stars 1 review

Should a Root Canal Be Done with the Old Crown in Place??

Is is very common to have the root canal done through a crown. I am not concerned about that or that being a problem.

It sounds like once the pain stopped, and the old crown was removed that there was more decay under that crown than would have been anticipated from looking at the outside of it. It is rare, but not impossible to have an unexpected surprise like this. 

In situations where I am concerned there could be a really deep cavity under the crown I might take off the old crown first. In my practice I would want to go back and take a hard look at any other old crowns to make sure that the same issue wouldn't show up again there. 

Like most situations in dentistry, ask good questions to your dentist. Listen well. If you are confused or even don't like the answer, ask more questions. Don't start a new treatment until you are comfortable with the pro's and con's of what may occur. Great communication before, during, and after, make for a great dental experience.

Can root canals be done through an old crown

Sorry to hear that your  Doing root canal through a crown is not unusual, however  the older the crown , the less the chance that the tooth can be restored . The problem is that  old crowns were mainly were fully or partially made out of  metal. Therefore, the dentist cannot detect the amount of destruction under the crown since x-rays do not penetrate through metal. Some patients cannot afford to pay for root canal and renew the crown and dentists try to buy "time" for their patients so that financially they do not undergo excessive cost. Therefore they perform the root canal first, and then they renew the crown.

Now that the tooth needs extraction , the best option is placing an implant . Good luck.


Soheyla Marzvaan, DDS
Orange County Dentist
4.3 out of 5 stars 6 reviews

Old root canals.

Sorry to hear your found out after the RCT that the tooth was too deteriorated.  It probably should have been picked up at the time the RCT was done.  Best treatment at this point is to remove the root and replace with an implant.  Second preference would be a bridge. When the tooth is extracted make sure the socket is "grafted or an immediate implant is placed.

Lawrence Singer, DMD
Washington Dentist
5.0 out of 5 stars 4 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.