Expert: Frederick R. Liewehr DDS, MS, FICD - 12/30/2006

Question
Have there been any recent advances in locating accessory canals specifically in a tooth that is calcified?  How about a crack?  I have numerous digital and standard x-rays over the past 3 years of #3.  No crack is ever evident.  It is calcified.  After RCT in august I've developed some chewing pain on it as well as some cold sensitivity.

I know even a poorly done root canal would stop cold...

Therapy was done by an eminent endodontist aided by a microscope.

He and my DDS both think it looks clean and well done.  It has a large restoration on it under the 5 year old crown.  We've basically taken it out of occlusion.

So - does the microscope help determine cracks and accessory canals?

THX

Answer
There are a lot of questions there, Bob, but it seems like you are telling me that you have a tooth that was endodontically treted that has developed chewing pain and cold sensitivity. You are corrrect in saying that there would be no cold sensitivity in a tooth that has had endodontic therapy. There is always an outside chance that the tooth could have a canal that was untreated that is sensitive to cold, but the odds are much better that the cold sensitivity is coming from another tooth. The best way to find out if this is the case is to have your dentist test your teeth with cold.

If your tooth had a vertical root fracture, it could be sensitive to chewing. However, if it is crowned, it is hard to imagine how it could become fractured now.

As for the microscope, it is a wonderful aid for us, because it provides both light and magnification while we work. On the other hand, it is not magic either, and canals have to be located by knowing where they may be and looking for them. As for cracks, the light and magnification are helpful, particularly if used in conjunction with staining.

So, as for your problem, have your dentist try cold to determine which tooth is the problem. If it is in fact the endodontically treated tooth, then it may be worth looking for another canal. Good luck.

Dr. Liewehr