Extracanal invasive resorption: an update.

Although it has been discussed since 1920, the entity of extracanal invasive resorption (EIR) remains misunderstood from a nomenclature, diagnostic, and treatment standpoint. At least 10 terms for it have been published in the dental literature. The key to diagnosis is that the pulp canal space has not been invaded by the resorption. Therefore, the pulp will respond to vitality testing. From a treatment standpoint, a differentiation must be made between the three types of EIR--intraosseous, crestal, or supraosseous. The latter condition may not require endodontic treatment, whereas it is necessary for the other two conditions. Regardless of the EIR's site, its successful treatment requires the debridement and obliteration of the external portal of entry and the resorptive defect.