The crown is the visible top part of a tooth in the mouth. It has an outer hard layer of enamel and a second, softer layer with fine nerve endings known as dentin. The two layers work together to enclose and protect the nerve or pulp tissue, which gives the tooth its strength. The nerve is sensitive to temperature and pressure changes. The nerve tissue narrows and extends down the length of the root, where it is housed in a narrow canal known as the root canal. The canal is simply a passage that houses the nerve and ends at the tip of the root. Teeth with multiple roots have a nerve running through each canal. Furthermore, these nerves have numerous fine branches that crisscross within the root. It is indeed a highly complex system.
