What are some of the considerations for removing a broken instrument from a root canal?
A. The ability to access and remove a broken instrument will be influenced by the cross-sectional diameter, length and curvature of the canal, and further guided by the depth of external concavities. As a rule of thumb, if one-third of the overall length of an obstruction can be exposed, it can usually be removed. Clinicians need to radiographically visualize if the broken instrument is in the coronal, middle or apical one-thirds of the root. Instruments that lie in the straightaway portions of the canal can usually be removed. If a separated instrument lies partially around the curvature and if safe access can be established to its most coronal extent, then removal is oftentimes still possible. If the entire segment of the broken instrument is apical to the curvature of the canal and safe access cannot be accomplished, then removal is usually not possible.
