Evidence-based dentistry: endodontic failure--how should it be managed?

To review the evidence on the most appropriate management of failed endodontic treatment.

Appropriate articles were selected from the international literature.

There was good evidence that conventional endodontic treatment is associated with a successful outcome in a significant proportion of cases. The results of surgical treatment are more difficult to interpret since account should be made of the status of the existing root filling. However, there is evidence of an increased success rate with a satisfactory orthograde root filling.

It is difficult to make direct comparisons from cited studies to advance a clear argument in support of one treatment modality. However, it is judged that a conventional endodontic retreatment approach is the most appropriate in the first instance, providing access to the root canal is possible. This does not preclude a subsequent surgical approach. Teeth that are permanently restored soon after retreatment are more successful than those which are not. There are significant challenges in setting up prospective research studies to directly address the problem of the failed root filing.