This is the treatment of the inside of the tooth, carried out either to remove a nerve in the case of deep caries or to treat an apical lesion when a previous root canal therapy has failed.
Root canal therapy of a vital elements
This is the branch of dentistry that deals with the therapy of the endodontium, the space within the tooth that contains the dental pulp.
Endodontic therapy is resorted to when a lesion (carious or traumatic) causes an alteration of the pulp tissue to the point of necrosis.
It is also possible to resort to this method when the tooth is to be involved in a prosthetic rehabilitation that, due to the considerable reduction of tooth tissue (preparation of the abutment), would lead to an increase in residual sensitivity or irreversible pulpal alteration (pulpal necrosis due to iatrogenic causes).
It may also be necessary when there is extensive destruction of the tooth that makes it impossible to reconstruct it with a good guarantee of success without having to resort to ‘anchoring’ the filling around a pin that is introduced into the canal to give stability to the reconstruction itself.
Root canal therapy necrotic elements
It is often necessary to resort to root canal therapy even after a carious process undergoing extensive reconstruction that affects the pulp chamber to the point of necrosis. To understand whether the pulp of a tooth is in necrosis, the signs are: a thermal cold sensitivity test with a negative result; the tooth is extremely painful on percussion; the patient reports a subjective sensation of ‘high tooth’. In this case the procedure is the same as for all root canal treatments and if necessary before closing the endodontic space, disinfectants are used to quickly reduce the symptoms described above.
Root canal retreatment
Endodontic retreatment is one of those sometimes more complex practices. The objectives of reprocessing are identical to those desired at the end of endodontic treatment performed on the untreated tooth, i.e. to have a devitalised tooth at the end but without lesions at the apex.
The need for and causes of root canal re-intervention can be manifold. The presence of a radiographically identified periapical lesion, accompanied by pain and/or recurrent abscess manifestations, is often considered an absolute indication for intervention.
The cause of most endodontic treatment failures is an inadequate apical seal, which is not necessarily attributable to operator error, but very often to the complexity of the endodontic system. In this case, non-surgical endodontic treatment is often preferred to surgery or extraction. The removal of the previously placed root filling material, a difficult and tedious procedure, and the creation of a new apical seal are prerequisites for a successful reprocessing. This type of therapy is not always possible if cements or non-removable posts have been placed within the canal, or if the tooth in question is undergoing major prosthetic reconstruction.
Endodontic surgery and apicoectomy
In the presence of apical lesions to the tooth that do not respond to conventional therapy or that cannot be treated because access to the canal is no longer possible due to the presence of crowns, root canal pins or foreign bodies, the lesion is removed by endodontic surgery or apicoectomy, followed by the removal of 3-4 mm more apical of a tooth root.
It is not indicated to perform an apicoectomy when the tooth roots are too short to withstand further shortening, when the root(s) are fractured or when the tooth is to be extracted.
