Every tooth in our mouth has 3 main structures. First is the Enamel which is the hardest structure of our body & even harder than bone. Second is Dentin which is located beneath the Enamel & is less harder than it. Finally, the Pulp which has the nerves, blood vessels, & lymphatics. The pulp is the organ responsible for giving a life to the tooth. When any kind of harmful stimulus reaches it, it manifests itself as inflammation & pain.