Each tooth contains a long, thin strand of dental pulp that contains the nerves and blood supply that extends into the root canal system. The blood vessels provide nutrients to the tooth and the nerves provide sensation. When the nerve is intact the tooth is vital and healthy. Bacteria can penetrate into the pulp through dental decay or tooth fracture causing destruction of the blood vessels and nerves within the pulp. As the tissue breaks down within the pulp an infectious process begins that ultimately leads to the constriction of blood supply and death of the nerve. The infectious process causes a build up of pressure within the tooth, usually causing pain, and over time an abscess develops. There are situations where a nerve becomes infected causing an abscess that is visible on the gums or on a dental x-ray, but the patient perceives no pain or is asymptomatic. To halt the infectious process and prevent destruction of bone and tissue, the degraded tissue must be removed.
Many people are perplexed when seemingly solid teeth with little or no dental work require root canal therapy. An often overlooked biological phenomenom is the calcification of the dental pulp -
a process that is almost identical to developing kidney stones. As we age, calcific deposits are laid down in the pulp chamber slowly constricting its size, helping to shield the nerve and minimize sensitivity. However, if the deposits reach the point where they cut off the blood supply in the very thin capillaries, the nerve will die, and as dead tissue leaks out of the canal system into surrounding bone tissue a dental abcess forms. This type of nerve death does not require bacteria to form an abcess but does require root canal therapy to allow the bone to heal and reform.
Root canal treatment may also be required when a patient is experiencing pain or severe sensitivity. Sensitivity to percussion or temperatures or when putting pressure on the tooth during eating are signs that a nerve is inflamed. The dentist must determine if the inflammatory process is reversible or irreversible. When the diagnosis is irreversible, the patient has only two options: root canal therapy or extraction.
Root canals are designed to help save compromised teeth. During the procedure the nerves within the roots are thoroughly cleaned and removed and the canal system is shaped to allow for a permanent filling and sealing of the root canal system.