The results of the present ex vivo comparative study cannot be directly applied to the clinical situation. Difference between both groups remains completely unclear; maybe the amount of extrusion is harmless in both groups or similarly deleterious for the periradicular tissues in both groups or may be dose-related to the amount of the extruded material.

Sinus tracts (or fistulas) are a common manifestation of pulpal necrosis that requires conventional -or rarely surgical- endodontic treatment in order to heal. They are mainly identified intraorally and in rare cases they manifestate extraorally, depending on the causative tooth, root location, bone thickness and muscle inserts. Such conditions may be misdiagnosed and confused with other non-pulpal pathologies. A case of extra-oral submental sinus tract that was initially misdiagnosed by a physician as a non-odontogenic lesion is presented. Facial fistulas of endodontic origin, despite sparse, should be considered as an option in the differential diagnosis procedure. It is important that interaction occurs between physicians and dentists to avoid exposing patients to insufficient treatment schemes.

Deformation of SAF files occurred mainly as detachment of one of the arches or struts at connection points on the odd side of the file. In no case did its mechanical failure result in metal fragment retention in the root canal.