Expert: Steven Litwin DDS - 7/4/2009

Question
Hey doc, I have a question about infections. You see, if there is an infection on the bone, I know the treatment would usually be a root canal. So after the root canal procedure, is it required to take antibiotics? Is it a must to fight off infection?

And if the root canal is done, then the infection would surely go away, no matter what?

Is it possible for a root canal to be successful, but for the infection to remain on the bone?

And if the infection does get worse, meaning after the root canal, there is even shaper pain than before, will x-ray show the infection as bigger than before? Thanks!

Talk to you soon, and have a great 4th of July!

Lea

Answer
Hi Lea,

Thanks for the question.  Lea a root canal is performed not because of an infection on the bone but because the nerve within the tooth is infected. As a result of this infection an abcess, cyst, or garunuloma (all of which are localized swellingings at the tip of the roots and surrounding bone)develops and usually causes pain due to pressure buildup of the fluid filled lesions. Root canals are not always followed with antibiotics. It depends on many factors including whether there is facial swelling, positive drainage during the procedure, and systemic effects such as the presence of fever. If all of the above are not present and there is no bleeding during the procedure then it is usual not to prescribe antibiotics at this point however things can certainly change after the fact which would necessitate that medication. If the original problem is correctly diagnosed to be an infected pulp (tooth nerve) and a root canal is successful then it is not normal for residual infection to remain indefinitely. It can take some time for the apical lesions to dissipate after the procedure and can vary from person to person. That is why the patient needs to be monitored for several months following the procedure to make sure there is total healing. WIth regard to pain and size of infection there is no correlation. A residual infection can persist and not get larger however the pain associated with it can become severe. A radiograph may show the lesion but not always as the lesion can be very small and may not be the actual cause of the pain. Other issues including premature contact on the tooth when biting and fracture root can also be causing the discomfort. Of course common sense rules on the part of the patient in that if there is worsening discomfort following a root canal there should be a followup with the treating dentist to allow for a proper diagnosis. Hope this helps and wish you the best.

Steve Litwin DDS