What is the terminal shank of a periodontal instrument?

• A. Lower shank closest to the working end of the instrument
• B. Upper shank farthest from the working end of the instrument
• C. Shank that determines the instrument's width
• D. Shank that is always straight

Answer: (A)

The terminal shank is the part of the instrument that matters most for how the blade reaches and adapts to the tooth. It is the end portion of the lower shank, the segment closest to the working end where the blade is attached. This portion determines the angle and reach of the blade as you engage the root surfaces, especially in deeper pockets or around posterior teeth. The upper shank sits closer to the handle and does not define this working-end behavior. The instrument’s width is set by the blade or tip, not the shank, and shanks can be curved or angled rather than always straight. So the terminal shank is the lower shank closest to the blade.