Which one of the following items is correctly used to extirpate the pulp contents during endodontic treatment?

The barbed broach is specifically designed for extirpating pulp tissue during endodontic treatment. It features small, barbed projections along its length, which allow for effective grasping and removal of the soft pulp contents from the root canal. This instrument is particularly useful because it can penetrate deeply into the canal and engage the moist, necrotic pulp, making the process of cleaning and shaping the canal space more efficient.

The finger spreader, while important in endodontics, is primarily used for laterally condensing filling materials, not for removing pulp. The Gates Glidden drill is used primarily for enlarging the canal but not for the actual removal of the pulp tissue. Healthy navigation and visibility in the canal are crucial, but it does not serve the same purpose as a barbed broach when it comes to pulp extirpation. Hand files are also used for cleaning and shaping the roots, but their design is not optimized for the initial removal of pulp tissue to the extent that a barbed broach is. Thus, the barbed broach is the most appropriate choice for effectively extirpating pulp contents in endodontic procedures.