A root canal is a treatment to repair and save a severely damaged or infected tooth instead of removing it altogether. The procedure involves removing the damaged area of the tooth (the pulp). It is then cleaned and disinfected and afterwards it is filled and sealed.
The common causes affecting the damaged area are a cracked teeth, cavities, and repeated dental treatment in the same area. The cleaning of the canals inside the tooth's root is where the phrase “root canal” comes from. For years, root canal treatments were painful. With dental advances and local anesthetics however , most people have little if any pain with a root canal today.