It's possible to experience some discomfort after a root canal treatment, but the severe pain should be gone and it should soon settle down. Once a tooth has been root treated it no longer has any nerve of its own. So, it cannot hurt on hot/cold or sweet stimuli, but it can hurt on pressure or if the tooth splits. This sensation comes from the tissues around the outside of the root. If you have pain from a previously root filled tooth, contact us.