Management of an extensive invasive root resorptive lesion with mineral trioxide aggregate: a case report.

External invasive resorption is an uncommon but aggressive type of external resorption. This report outlines the management of an advanced case of external invasive resorption with mineral trioxide aggregate (MTA). The clinical and radiographic follow-up after 60 months revealed a functional tooth with a stable periodontal condition and no evidence of any further resorption.