08 October 2022

---

The access cavity in retreatments: redefinition and management of iatrogenic errors

By Alessandro Fava

---

Endodontic retreatments often represent a fundamental crossroads for the fate of the single dental element. Even more so, when dealing with a multidisciplinary treatment plan, endodontic success can condition the prosthetic and aesthetic choices. 

Materials and methods  

The analysis of the coronal seal is one of the first evaluations to be carried out on a tooth to be subjected to endodontic retreatment: if there are doubts about the integrity of the coronal seal, the advice is to remove the restoration in correspondence with the element. to be retracted and expected to be redone. 

The seal must be effective before, during and after root canal treatment: a good coronal seal helps to increase the overall result. To ensure a seal, periodontal surgery is sometimes necessary for the correct restoration of biological width and, consequently, to be able to isolate the operating field by means of a rubber dam. 

The removal of fillings, crowns or bridges also allows you to perform a scrupulous biomechanical analysis and to draw up a restorative prognosis of the element in question. The use in this phase of atraumatic techniques for the underlying dental tissue is essential. 

One of the most important steps, like a primary endodontic treatment, is the redefinition of a correct access cavity: in this way the subsequent phases of probing and canal shaping will be easier. 

The removal of endocanal retentions (post and stump, prefabricated, fiber) is still today considered a difficult step and at risk of causing root fractures. The knowledge of the techniques and the use of suitable devices allow instead to be able to overcome this obstacle in safety. 

Only after having removed any intra-canal retentions in the most conservative way possible can the access cavity be approached, paying close attention to intercepting over-preparation or under-preparation errors so as to avoid further iatrogenic damage or weakening of the residual dental structure. 

Excessive preparation errors are much more frequent: they often complicate the search for any non-instrumented canals by deleting the usual reference points used in identifying the canal anatomy. Sometimes they result in real iatrogenic damage: perforations of the pulp chamber, serious damage to the residual dental structure, capable of putting the prognosis of the element at risk. 

Results and Discussion  

The restoration of a correct access cavity allows to accurately explore the floor of the pulp chamber so as to be able to search for any untreated canals or canal isthmuses which represent one of the most frequent causes associated with the presence of periapical lesions of endodontic origin. 

Thanks to the introduction of mineral trioxide aggregate and its most recent derivatives, perforations can be repaired with good predictability of the clinical outcome. 

Conclusions  

The possibilities of recovering an element seriously compromised from an endodontic point of view pass through the possibility of regaining the most linear access possible to the entire root canal system: the use of specific devices, adequate enlargement and the introduction of materials. bio ceramics associated with the experience accumulated in the field allow to raise the prognosis. 

Clinical significance  

Success in endodontic retreatments is conditioned by any anatomical alterations caused by previous operators. It is therefore necessary that an approach is used that allows restoring the ideal conditions to then face the probing, mechanical shaping, cleansing and obturation procedures. 

This article was originally published in "Dental Cadmos."