Expert: Joel S. Teig, DMD, Diplomate ABOMS, retired - 12/14/2009

Question
QUESTION: Dr. Teig,

After a root canal procedure, if there is a gray stain on the tooth, does that indicate something is wrong? Are there any tooth diseases OR tooth problems out there that are associated with light gray stains or any stain for that matter? My dentist told me it was just a stain, but then I'm concerned if it is something else. Perhaps the stain is not so harmless after all? Also, I'm having pain around that area too after my root canal procedure but am wondering if the light gray stain is indicative of something else. Please tell me what you know about this issue. Thank you.

ANSWER: Lana -  By itself, gray staining of a tooth after root canal therapy is not a sign of any problems.  During the root canal treatment, the dentist, while removing the nerve, probably encountered a little bleeding within the tooth.  This bleeding, just like a bruise causes a discoloration of the skin, can cause a discoloration of the tooth.  The main difference is that the stain does not resolve on its own in the tooth.  To eliminate the stain, whitening of the tooth often helps or a crown needs to be made to cover the tooth.   What I don't like is your pain in the area.  After root canal treatment, all symptoms should resolve within a couple of weeks.  If it has been more, the source of the pain needs to be addressed.  Your dentist will need to do that or refer you to a specialist for an evaluation.

---------- FOLLOW-UP ----------

QUESTION: Thanks Dr. Teig for your answer. I want to clarify something, if I may. I'm not talking about discoloration of the tooth. I'm talking about an actual stain, light gray stain right on the tooth. The dentist said it can be scraped off with a tool. However, I'm wondering if that stain indicates anything wrong, or if there are any tooth issues or diseases associated with stains. The stain does not occur throughout the whole tooth. It's in the back of a front tooth, and I can see it with the help of 2 mirrors. It is not on the permanent filling, but rather near it.  Thank you.

Answer
Lana - Maybe I was not specific enough.  The discoloration from internal bleeding does not necessary spread evenly throughout the tooth, but like a bruise, it can just be in one spot.  I don't understand how the dentist says it can just be scraped off.  If it can be scraped off, it is not a stain, but some material fused to the surface of the tooth.  

So if it truly is a stain, evident after the root canal treatment, it is from the root canal and the dispersal of blood and poor cleaning of the area by the dentist.  This can be reduced, but usually tooth whitening, if done correctly can greatly reduce any staining.  

I think I am correct unless there is other treatments done by the dentist that I do not know of.