A ______ is used to outline the tissue area for gingivectomy.

A pocket marker is specifically designed to outline the area of tissue that will be removed during a gingivectomy procedure. This instrument allows the dental professional to precisely mark the gingival tissues to create a clear and defined surgical incision line. By using a pocket marker, the clinician can assess the depth of the periodontal pockets and determine how much tissue needs to be excised to improve the patient's periodontal health.

This tool is vital for ensuring accuracy in surgical planning and enhances the effectiveness of the procedure by providing a visual guide. The accurate marking of tissue with a pocket marker can lead to more predictable surgical outcomes and reduced trauma to surrounding tissues. Other instruments like a scalpel, probe, or curette serve different purposes in dental procedures and do not fulfill the specific function of outlining tissue for surgical removal.