Which instrument is used to remove the pulpal fibers of an abscessed tooth?

The correct choice is the broaches, which are specifically designed for the purpose of cleaning and shaping the root canal system of teeth, particularly in cases of pulp necrosis or abscess. Broaches are thin, flexible instruments with a series of sharp blades that are effective for removing pulpal tissues and debris from within the canal.

In endodontic procedures, the ability to reach deeply into the canal while effectively grasping and removing soft tissue is crucial, which is where broaches excel compared to other dental instruments. They allow for precise removal of pulpal fibers that may be contributing to infection or inflammation in the tooth.

In contrast, other tools have different primary uses. An excavator is typically used for removing carious dentin or debris from a cavity rather than specialized pulp tissue. A scalpel is primarily used for soft tissue incision rather than for canal cleaning, and forceps are designed for extracting teeth, not for removing pulp tissue within the tooth itself. Understanding the specific functions of these instruments is key in dental procedures, particularly when addressing issues related to pulp health and abscesses.