Endodontic failures--changing the approach

The underlying reason for endodontic failures is almost invariably due to bacterial infection. The bacteria may be situated within a previously missed or uninstrumented portion of a root canal, infiltrate via a leaky coronal restoration and root filling, or cause contamination from an extra-radicular infection. Management of the failing root canal filling begins with the identification of the source of persistent infection. Should the infection be present within the root canal system, such as a missed canal, orthograde retreatment is the choice of treatment. This is also true for asymptomatic cases which had been inadequately obturated and which require the placement of a dowel into the canal for restorative reasons. Periapical surgery is best reserved for cases with no sign of healing after orthograde retreatment and those with extra-radicular infection. This paper discusses the relationship between endodontics and restorative dentistry, treatment planning for endodontic failures, and the reported rates of success with orthograde and surgical retreatments.