When deep decay or a traumatic injury reaches the innermost layer of a tooth, it can cause severe discomfort, signaling that the inner tissue has become infected or severely inflamed. This condition often leads to a recommendation for Root Canal Treatment, or endodontic therapy. The goal of this treatment is to eliminate the source of the pain and save the natural tooth from extraction. This process involves the removal of the damaged internal tissue, which stops the nerve from transmitting pain signals.
Understanding the Dental Pulp
The structure commonly referred to as the “nerve” is actually the dental pulp, a soft tissue located in the center of the tooth within the pulp chamber and the root canals. This pulp is a network composed of sensory nerves, blood vessels, and connective tissue. Its function is to provide nourishment to the dentin layer and transmit sensations, like temperature and pressure.
When bacteria from deep decay penetrate the outer layers, they infect the pulp, causing a condition called pulpitis. Because the pulp is encased within the hard walls of the tooth, there is no room for the inflamed tissue to swell. This pressure on the sensory nerves causes the intense, throbbing pain associated with an infected tooth. To eliminate the infection and the pain, the dentist must remove this diseased tissue from the interior of the tooth.
The Root Canal Procedure
The process begins once the area has been numbed with local anesthesia and the tooth is isolated with a protective rubber sheet called a dental dam. The dentist uses a high-speed handpiece to create a small access opening through the biting surface of the tooth, reaching the pulp chamber. This opening provides a direct pathway into the root canals, where the infected tissue resides.
The next phase is the core of the treatment: removing the soft tissue from the chamber and the root canals. Specialized, increasingly larger instruments, known as endodontic files or reamers, are used to mechanically clean and shape the walls of the narrow canals. This action removes the bacteria, debris, and the entire diseased pulp, including the sensory nerve fibers.
Throughout this process, the canals are repeatedly flooded with an irrigating solution, most commonly a diluted solution of sodium hypochlorite. This disinfectant washes away the loosened tissue and bacteria, ensuring the canal system is thoroughly sterilized. The shaping process creates a clean space ready to be sealed. Once the canals are cleaned, shaped, and disinfected, the removal of the nerve and infected material is complete.
Sealing and Restoring the Tooth
With the root canal system cleaned, the next step is to seal the interior to prevent future bacterial contamination. The cleaned space is filled with gutta-percha, a biocompatible, rubber-like substance derived from natural tree sap. This material is thermo-plastic, meaning it can be heated and compressed to fill the entire space of the canal.
Gutta-percha is cemented into place using a root canal sealer, such as a zinc oxide eugenol-based or a modern bioceramic material. The sealer fills microscopic gaps between the gutta-percha and the canal walls, creating a hermetic seal against re-infection. This sealing process, known as obturation, is a major factor in the long-term success of the treatment.
After the root canals are sealed, the access hole must be filled, usually with a temporary or permanent restorative material. In most cases, a final restoration, such as a dental crown, is required following the procedure. The tooth structure can become brittle after the pulp is removed, and a crown provides the necessary structural reinforcement to protect the tooth from fracture during chewing.
Recovery and Alternatives
Following the root canal procedure, it is common to experience mild sensitivity or discomfort for a few days, particularly when chewing. This is managed effectively with over-the-counter pain relievers. The dentist will provide specific instructions on temporary dietary restrictions and oral hygiene. A follow-up appointment is often necessary to place the final restoration.
The primary alternative to root canal treatment is extraction, especially when the tooth is severely damaged or the infection is widespread. Removing the tooth eliminates the source of the infection, but it creates a gap that can cause surrounding teeth to shift. To maintain proper bite function and prevent bone loss, an extracted tooth needs to be replaced with a prosthetic option like a dental implant or a bridge.