Commonly called Root Canal Therapy, this procedure is needed when a tooth has a cavity or fracture that has grown large enough that it has invaded the nerve. When the nerve is invaded it dies partially or fully and an abscess occurs. An abscess is a hole in the bone that forms from the breakdown of the nerve. The hole fills with puss and causes pressure in the bone with ensuing pain. Bone has hollow spaces called trabeculae. So that is why it hurts sometimes and other times not. The infectious puss gains pressure and pushes its way into the next chamber with ensuing pain. Finally it tracks out into the jaw causing a puss filled boil or swelling.
Antibiotics can relieve pressure and pain but the root canal procedure makes it permanent. I remove the nerve and debris, relieve puss pressure and then fill the canal with a natural rubber material called gutta-percha. Once the tooth is plugged, I place a ceramic post in the biggest canal and fill the hole I made with white filling material. This is called a post and core. Finally an impression is taken for a new crown. The crown is needed to protect the newly dried out tooth. With no blood supply, a tooth is more brittle and needs a helmet to protect it.