I first located the pulp chamber which was slightly more mesial than anticipated. The canal accesses were close to each other. I decided to treat the distal canals first, since the mesial canals were sharply curved and required more care in their preparation.
I needed a second appointment to complete this case. The mesial canals join to end in one foramen and appear to cross the distal canals. The mesial canals were filed initially with flexofile 06 files (by Dentsply) and then gradually opened up to size 20 Protaper. I used Hedstroem 08,10 and 15 in this process of recapitulation and carefully cleaning and shaping the canals.
The x-ray below shows the completed case. The patient was asked to return to her dentist for a coronal restoration in order to protect the tooth from excessive biting forces.