Patient was referred for root canal treatment of tooth #3. Diagnosis: PN/SAP (pulpitis/necrosis with symptomatic apical periodontitis). After completing the access preparation, the orifices were enlarged with ProTaper Universal SX.
While scouting for working length, a .10 hand file separated in the MB1 canal. The tip was near the junction with MB2, and the separation occurred close to the orifice. A sponge and Cavit were placed, and a new radiograph was taken.
Ultrasonics were used to trough around the file, working mostly lingual to the instrument and using the MB2 canal as a guide until MB2 joined MB1.
This approach allowed controlled removal of tooth structure palatal to the file, with minimal dentin removal along the outer canal walls. During this process, approximately 3 mm of the coronal portion of the file fractured and was removed.
At that point, I switched to TFRK ultrasonics and continued until 2–3 mm of the file was exposed and mobility was evident.
An EndoCowboy LassoTip (0.12 mm) was then used to lasso the fragment, and the file was removed in its entirety without complication.
The case was completed uneventfully, with no additional visit required. The post-op radiograph confirmed minimal loss of tooth structure to achieve file removal.