Sometimes bad things happen to good teeth. Religious scholars have debated this for centuries, and the general conclusion is life sometimes sucks. Root canals are done when your tooth hurts, has an infection, is cracked, or has a cavity in or near the pulp. You may find a tooth very sensitive to hot and cold, throbbing, painful when you chew, or swollen near it. Now you need a root canal. Long and short of it is we clean out the nerve, shape the root canals (hence the name!) and fill them with material. A crown is then typically placed on top of the tooth to protect it. Study this picture and then you are ready to go out and start doing your own!