The dental pulp is the soft tissue that contains nerves, blood vessels, and connective tissue. The dental pulp lies in the pulp chamber and root canals of the tooth. In root canal treatment, pulp along with its nerve supply is removed. 

However, a tooth's nerve is not vitally important to a tooth's health and function. Its only function is sensory i.e. to provide the sensation of heat or cold. The presence or absence of a nerve will not affect the day-to-day functioning of the tooth. However, after treatment, the tooth is less viable and more susceptible to fracture.