title: Retreatment of a 6-canalled mandibular first molar with four mesial canals: a case report.
abstract: Successful root canal treatment requires adequate knowledge regarding morphologic variations in root canal system of teeth. This report describes a six-canalled mandibular first molar with four mesial root canals requiring endodontic retreatment. The two additional canals in the mesial root were found during retreatment with the aid of illumination and magnification. In conclusion, the possibility of atypical morphology and additional canals should never be overlooked.
authors.affiliation: Department of Endodontics, Dental School/Dental Research Center, Tehran University of Medical Sciences, and member of Iranian Center for Endodontic Research, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Aminsobhani
authors.forename: Noushin
authors.initials: N
authors.lastname: Shokouhinejad
authors.forename: Sholeh
authors.initials: S
authors.lastname: Ghabraei
authors.forename: Behnam
authors.initials: B
authors.lastname: Bolhari
authors.forename: Abdollah
authors.initials: A
authors.lastname: Ghorbanzadeh
keywords: First Mandibular Molar; Four Root Canal; Mesial Root