Endodontic Therapy

Definition

Endodontic therapy is a sequence of dental treatments for the infected pulp of a tooth which results in the elimination of infection and the protection of the decontaminated tooth from future microbial invasion.

While popularly referred to as a "root canal," the root canal is actually the anatomical space within the root of a tooth; the therapy is the cleaning, shaping, and filling of that space.

Indications for Treatment

Endodontic intervention is required when the dental pulp becomes inflamed or infected. Common causes include:

Deep Dental Caries: Bacteria reaching the pulp chamber.
Dental Trauma: Impact causing pulp necrosis or internal resorption.
Fractured Teeth: Cracks extending into the pulp.
Irreversible Pulpitis: Severe inflammation where the pulp cannot heal, characterized by lingering pain to cold/heat and spontaneous pain.

The Procedure (Step-by-Step)

1. Access Preparation

The dentist or Endodontist creates an opening through the crown of the tooth (occlusal for molars, lingual for incisors) to reach the pulp chamber.

2. Cleaning and Shaping

The diseased pulp tissue is removed using specialized endodontic files.

Irrigation: The canals are flushed with disinfecting solutions, most commonly Sodium Hypochlorite (NaOCl), to dissolve organic debris and kill bacteria.
Instrumentation: Files are used to shape the canals into a tapered form to allow for effective filling.

3. Obturation

Once the canals are cleaned and dried, they are filled with a biocompatible material to prevent re-infection.

Gutta-percha: A thermoplastic latex material that is the standard for root canal filling.
Sealer: A medicinal cement used to ensure a fluid-tight seal between the gutta-percha and the canal walls.

4. Restoration

Because an endodontically treated tooth is "non-vital" (brittle) and often has significant lost structure, a final restoration is required.

In most posterior teeth, a Dental Crown is mandatory to prevent tooth fracture.

Success Rates and Prognosis

Modern endodontic therapy has a success rate of approximately 85% to 97%. Factors affecting prognosis include:

The presence of a pre-existing periapical lesion (bone infection).
The quality of the final coronal seal (the filling/crown).
The complexity of the root canal anatomy (e.g., curved canals or calcification).

Complications

Sodium Hypochlorite Accident: Extrusion of irritant past the apex.
Instrument Separation: A file breaking inside the canal.
Perforation: An accidental hole made through the side of the root.