Treatment of Teeth with Necrotic Pulp

This treatment is indicated in the case of a tooth with a necrotic pulp, with or without a periapical inflammation; or when a tooth has been previously root filled and has to be retreated.

  1. Removal of caries, old fillings, etc. temporary buildup if necessary.
  2. Access preparation.
  3. Disinfection of the operative field and rubber dam with an antiseptic.
  4. The access cavity is filled with a biocompatible antiseptic irrigant, e.g., sodium hypochlorite. A thin endodontic file is carefully moved to a level that is estimated to be 1-2 mm short of the radiographic apex.
  5. By means of a radiograph (working length x-ray), taken with the instrument in the canal, the working length is decided.(Usually 1 mm short of the radiographic apex).
  6. Cleaning of the canal is started with thin instruments to avoid pushing necrotic, infected material through the apical foramen.
  7. Cleaning and shaping of the root canal using copious amounts of irrigation solution.
  8. When the cleaning and shaping is finished, the canal is dried and filled with a calcium hydroxide paste.
  9. The canal can be filled during the next visit if there are no symptoms, no exudate, and any fistula has healed.

If there are symptoms and/or exudate, and/or the presence of a fistula, continue the treatment. This is a sign of remaining infection. When a fistula is still present after 2-3 visits, try to find out if there is another reason for the remaining fistula - root fracture, necrotic neighboring tooth etc.


When the root is not fully developed, an apexification procedure is carried out. After thorough cleaning of the root canal, the calcium hydroxide is left for longer periods of time to give the root development a chance to continue. The intracanal medicament is usually changed after one month. After that, it is left for at least 6 months when a radiographic check-up is done. Usually the canal is cleaned again at this time and the canal is refilled with calcium hydroxide. Next radiographic check is done after another 6 months. If periapical healing and a closure of the root canal have taken place, the permanent root filling can be carried out. If root closure has not taken place, the tooth is checked again after another 6 months. Usually, an apexification procedure will give the desired result. However, in a few cases the root development will not continue and the canal has to be root filled without an apical stop.

Note 1: Apexification is a long term treatment that requires good temporary fillings.

Note 2: It is the elimination of infection from the root canal and not the action of calcium hydroxide that will make it possible for the body to continue root development. ( It is possible to carry out an apexification procedure successfully without the use of calcium hydroxide. However, a temporary calcium hydroxide root filling is a good means to keep the canal clean and free from infection.)

Root Filling

The important thing is to remove bacteria and their products, and tissue debris which can serve as food for bacteria. After that we can obtain healing. However, it is not clinically practical to leave empty root canals. Coronal fillings will leak and infect the empty, cleaned root canal; we need posts for retention etc. Thus, it is a prerequisite to seal the root canal with a root filling in order to protect the periapical tissues ( and the patient).

The root canal can be filled:

  • When the tooth is asymptomatic
  • When there are no clinical signs of infection or inflammation (no exudate, no fistula, no swelling, no redness etc.)
  • When the canal is properly cleaned and shaped

The endodontic method taught at Columbia University is a lateral condensation technique which is widely used in many countries. There are many root filling techniques available. The techniques are mainly depending on the properties of the root filling material. However, only a few methods have been evaluated for long term prognosis and unfortunately most methods are recommended and taught without any prognosis studies.