Fig. 1

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.

Fig. 2

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 working length, an electronic apex locator was also used.

Fig. 3

All the canals were shaped with Reciproc files (r25, r40) (VDW, Germany) according to the manufacturer’s instructions.

Copious irrigation with 5mL syringe and a 27G notched needle with 5,25% sodium hypochlorite was done all throughout the endodontic treatment.

Fig. 4

The canals were dried with paper points.

Fig. 5

The root canal obturation was done with gutta-percha and resin sealer with a continuous wave of obturation technique.

Fig. 6

A flowable composite resin was used to seal the root canal openings and the crown was subsequently restored directly with composite resin.

Fig. 7

At 12 months, the patient is completely asymptomatic and periapical radiography shows a significant decrease in the apical lesion associated to both roots.


Root canal morphology and configuration might present the clinician with a complex anatomy requiring more diagnostic approaches, access modifications, and clinical skills to successfully localize, negotiate, disinfect, and seal the root canal system. 


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