The structure of a tooth broadly consists of two parts, the crown, and the root. The crown is that part of the tooth which we can see in our mouth and the root is that part of the tooth which we cannot see and is deep inside the jawbone, holding the tooth firmly in place.
Structurally the upper layer of the tooth is called the enamel, the second layer the dentin and the third layer is the soft tissue in the core which consists of nerves, blood vessels, and connective tissue, and is called the pulp.
When the pulp is diseased and cannot repair itself, it dies. The cause of the pulp disease could be a deep tooth decay, repeated dental procedures on the same tooth, traumatic damage to the tooth, a gum disease necessitating root canal treatment (RCT), or Endodontic treatment. “Endo” in Greek meaning inside and “Odont” meaning tooth.