Expert: Lawrence Spindel DDS, www.lspindeldds.com - 11/14/2008

Question
Hi.  I have had several problem teeth, at least 4 root canals, one tooth was later extracted due to infection.  On one tooth, I had a root canal done about 2 years ago.  It felt fine after the root canal was done.  Recently, I developed pain in that tooth.  My dentist took x-ray's, and said it looked fine, but sent me to an endodontist to help figure this out.  He took more x-rays, and tested cold sensitivity with an ice cube.  Then he concluded I'd have to have a root canal done again.  Does this mean my dentist did not perform the root canal properly, or completely the first time?  As I understood it, when a root canal is done properly, it kills the nerve.  If the nerve is dead, then A.) how do I have pain cropping up after 2 years, and B.) what is the point of another root canal, the nerve is supposed to be dead?  I trust my dentist, and the endodontist, but I can't help but fear someone is not telling me something, as this just doesn't make sense to me.  Thanks for your time.

Answer
Dear Alisha,

It does sound like you should have your root canal retreated by the endodontist.  Root canals involve cleaning, shaping,and sealing the root canal system with an inert material that doesn't allow bacteria to gutta percha in the root canal system afterwards.

Dentists use gutta percha,  a pink inert rubbery material, to fill the canal along with sealer.  The sealer is often water soluble and can wash out from either irregularities or areas that are not filled with gutted percha.

I would not say that your dentist did something wrong, but obviously it does need to be reshaped and resterilized and sealed again.  Endodontists have 2 years of additional training after dental school and just do root canals. Often they can succeed, when a general dentist has not.

I have written an article titled "Why Do Root Canal Treatments Fail" and you can find it by copy and pasting this link on your browser.

http://www.metrodentist.net/latest/why-do-root-canal-treatments-fail.html

It should explain the most common reasons why root canals fail and it may help you understand the process better.  I hope I have answered your question and please feel free to contact me again with future dental queries.