When the pulp is diseased or injured, it dies. The most common cause of pulp death is a cracked tooth or a deep cavity. Both of these problems can let germs enter the pulp. Germs can cause an infection inside the tooth. Left without treatment, pus builds up at the root tip, in the jawbone, forming a "pus-pocket" called an abscess. An abscess can cause damage to the bone around the teeth.
Years ago, teeth with diseased or injured pulps were removed (extracted). Today, root canal treatment has provided a safe way of saving teeth.
A root canal is a procedure to remove and clean the infected pulp tissue. By removing the infected pulp, the tooth can usually be saved. Once the pulp has been removed, medication may be placed inside the empty chamber to stop infection. Eventually the chamber are refilled. It may be necessary, following a root canal, to crown the tooth.