When is it needed? Dental pulp, commonly referred to as the "nerve" of the tooth, and which is contained inside it, is actually a highly specialized connective tissue containing arteries, veins, nerve endings and connective cells (Fig. 1).

As a consequence of contamination with bacteria due to deep caries, or because of a trauma, the pulp becomes inflamed or infected : this is pulpitis, often a painful clinical condition.

Fig.1

Acute or chronic inflammation (with different speeds of evolution) may spread beyond the tooth apex to reach the surrounding alveolar bone, causing lesions that are known as abscesses or granulomas. These are visible in radiographs as a dark area (rarefied bone) around the root apex (Fig. 2).

Fig.2

This constitutes an absolute indication to endodontic treatment, the only alternative being to extract the tooth.

Another indication to endodontic treatment is when previous endodontic treatment has been executed poorly or has failed: this is endodontic re-treatment.

What is it exactly? Endodontic treatment consists in removing the pulp tissue, both from within the crown of the tooth and from the root, and replacing it with a permanent filling of gutta-percha and canal sealer, after having properly shaped the canal (Fig. 3).

Fig.3

How long does it take? Endodontic treatment is fairly long, especially for the molars, one or more sittings being needed depending on the particular case. The stages in endodontic treatment are:

• Diagnostic radiograph.
• Local anaesthetic (the entire treatment is pain-free).
• Temporary reconstruction of the clinical crown if it is badly damaged, so as to be able to work in optimal conditions, isolating the operative field.
• Isolation of the operative field by means of the so-called "dam": that is, a sheet of rubber stretched over a small metal arch and held in place by a metal hook.
• The pulp chamber is opened through the tooth crown.
• The canal or canals are located. The length is measured (from the crown to the root apex) by radiography and/or using an electronic apex locator.

The dose of radiation absorbed while taking a dental radiograph is minimal. The risk/benefit ratio is highly in favour of the benefit (that is, correct endodontic treatment).

• Instrumentation of the canal using an endodontic instrument that removes pulp, bacteria and infected matter, creating at the same time a cone shape, suitable to receive the filling material.
• Flushing with sodium hypochlorite, a powerful antiseptic, to obtain conditions as close as possible to sterility.
• Permanent filling of the canal with gutta-percha, a plastic material that can be modelled when warm, together with canal sealer (Fig. 4).
• Temporary filling of tht access cavity.
• Radiograph to verify that the treatment has been properly carried out.
• Prosthetic reconstruction of the tooth.

Fig.4

Will it hurt? Treatment is painless, thanks to the local anesthesia. In the two or three days after endodontic treatment there is generally a slight ache, which can be eased with an ordinary pain-killer. In extremely rare cases, with severe root infections, bacteria may be mobilized and escape beyond the root apex. An abscess may then develop, and naturally this is painful, but the complication does not compromise the success of the endodontic therapy that has been begun. The canals must be drained, for which it will be necessary to return to the office for a few minutes.

Of course, the dentist will prescribe proper medication to be taken during endodontic treatment, if necessary.

What are the benefits of endodontic treatment? The tooth is not lost, and, after prosthetic restoration, it can play again ist normal role in the dental arch.

The success rate of endodontic treatment, properly carried out and in normal conditions, is very high.

The percentage drops in cases of re-treatment, that is when the canal has already been treated but not properly (short treatment, errors in instrumentation, anatomic variations, etc.).

In these cases, however, surgery is possible and increases the success-rate: apicoectomy and retrogade filling.