Your teeth are held in place by roots that extend into your jawbone. Front teeth usually have one root. Other teeth, such as your premolars and molars, have two or more roots. The tip or end of each root is called the apex. Nerves and blood vessels enter the tooth through the apex. They travel through a canal inside the root, and into the pulp chamber.
During root canal treatment, your dentist cleans the canals using special instruments called files. Inflamed or infected tissue is removed. An apicoectomy may be needed when an infection develops or won’t go away after root canal treatment or re-treatment. An apicoectomy is done only after a tooth has had at least one root canal procedure and re-treatment has not been successful or is not possible. For example, re-treatment is often not a good option when a tooth has a crown or is part of a bridge. Re-treatment of the root canal would require cutting through the crown or bridge. That might destroy or weaken the crown or bridge. An apicoectomy is often considered in a situation like this.