Underneath your tooth's outer enamel and within the dentin is an area of soft tissue called the pulp tissue. While a tooth's pulp tissue does contain nerve fibers, it is also composed of arteries, veins, lymph vessels, and connective tissue. Each tooth's nerve enters the tooth at the very tip of its roots. From there, the nerve runs through the center of the root in small "root canals," which join up with the tooth's pulp chamber. Root canals are very small, thin divisions that branch off from the top pulp chamber down to the tip of the root. A tooth has at least one but no more than four root canals.
Why do I feel pain? When the pulp becomes infected due to a deep cavity or fracture that allows bacteria to seep in, or injury due to trauma, it can die. Damaged or dead pulp causes increased blood flow and cellular activity, and pressure cannot be relieved from inside the tooth. Pain in the tooth is commonly felt when biting down, chewing on it and applying hot or cold foods and drinks.
What is a root canal procedure? A root canal is a procedure done to save the damaged or dead pulp in the root canal of the tooth by cleaning out the diseased pulp and reshaping the canal. The canal is filled with a rubberlike substance called gutta–percha or another material to prevent recontamination of the tooth. The tooth is then permanently sealed, with possibly a post and/or a crown made of porcelain or metal alloy. This enables patients to keep the original tooth.
What happens after treatment? Natural tissue inflammation may cause discomfort for a few days, which can be controlled by an over-the-counter analgesic. A follow-up exam can monitor tissue healing. From this point on, brush and floss regularly, avoid chewing hard foods with the treated tooth, and see your dentist regularly.