A root canal is a procedure for removing the nerve and blood supply from a tooth in which the nerve has been infected or traumatized. We begin by placing a barrier (rubber dam) over the affected tooth; then we access the root-canal system through the tooth’s crown. We use files to remove the nerve and bacterial infection from inside the canal. After that, we shape, clean, and fill the tooth. Depending on the location of the treated tooth, we may find it necessary to place a crown over the tooth to protect it after the root canal is finished.