Observation of an unusually large spirochete in endodontic infection

Spirochetes in the root canal have been investigated only to a minor extent. Oral spirochetes have been detected particularly in the periodontal pocket, where small, medium-sized and large morphotypes have been reported. In the present darkfield and scanning electron microscopic study we describe a spirochete isolated from the root canal that is 7 times longer (140 microns long) and 5 times thicker (2 microns thick) than usual for treponemes.