Middle Mesial Canal of the Mandibular First Molar

Pre operative A 47-year-old female patient was referred to the Postgraduate Specialization Course in Endodontics at the Faculty of Dental Medicine of the University of Lisbon (FMDUL), by a colleague from Oral Hygiene, to perform non-surgical endodontic retreatment in the first right lower molar. Tooth 4.6 had a previous endodontic treatment and asymptomatic apical periodontitis. Probing was within normal depths in all surfaces except distolingual, where there was a localized pocket of 7mm. WL determination As a treatment plan, non-surgical endodontic treatment was suggested. The treatment was performed under an operating microscope, in 4 appointments. Upon establishing access with Ultrasonic tips, three mesial canals were found. The canals were scouted with 10k and 15k stainless-steel hand files. To determine the…