File Retrieval and Completion of Root Resection
A CBCT radiograph shows that the resection of MB root is incomplete leaving a large portion behind, where MB2 clearly presents with a periapical lesion in the apical third. There is a separated file in the palatal canal, and a sinus tract opening on the buccal gingiva, due to the infection in the MB2. I located the MB2 with a TFRK Micro Explorer under the microscope, and enlarged the orifice with the precurved TFRK-S tip, followed by a #10/.06 Micro-Opener, TFRK-GPR, ProTaper S1 to establish apical patency, and #20-#35 VortexBlue files to complete the root canal preparation. The MB2 was filled with mineral trioxide aggregate following the preparation.