The treatment of actinomycosis mimicking a retained root tip: a confusing case.

Actinomycosis is an infection caused by the actinomyces genus and is associated with trauma or previous infection. A 58-year-old male patient was referred from a private dental clinic for root extraction of the lower right molar. The x-ray showed fractured root-like material distal to the distal root of the lower right second molar. A biopsy during extraction of the root-like material was performed, which revealed a sequestrum with actinomycosis by a pathological examination. In this case, the radiopacity of the suspicious lesion was higher than that of the surrounding alveolar bone, which confused it with the root tip. The diagnosis of actinomycosis required long-term antimicrobial therapy, which is very different from simple extraction or removal of sequestrum.