Root canals are most commonly necessary when the nerve in your teeth becomes inflamed and may later die. A dead nerve is full of bacteria which will lead to a dental abscess. While antibiotics may help you feel better temporarily, as long as the dead nerve is present the abscess will not properly heal. The only way to remove the abscess is to remove the tooth or remove the dead nerve.
Root canals are a great option because they allow you to keep your own tooth. While we will remove the dead nerve and bacteria from the tooth, the remaining healthy portion is left intact. Typically a crown will be recommended following your root canal to protect the tooth from breaking.