Which clasp setup is shown?

Which clasp setup is shown?

• A. I-bar clasp
• B. T-bar clasp
• C. RPI
• D. Wrought wire combination clasp

Answer: (A)

Recognize the direct retainer’s shape. An I-bar clasp is a slender, cast bar that engages a tooth undercut with a simple, vertical-oriented arm. In the image, the retentive element is a single narrow bar aligned with the tooth’s long axis, extending toward the undercut without a broad crossbar or extra components. This clean, straight retentive arm sets it apart from a T-bar clasp, which would show a horizontal crossbar at the end, and from an RPI design, which would include a rest and a proximal plate in addition to the retentive arm. A wrought wire combination clasp would show bent wire segments rather than a single rigid bar. Therefore, the setup shown is an I-bar clasp.

Recognize the direct retainer’s shape. An I-bar clasp is a slender, cast bar that engages a tooth undercut with a simple, vertical-oriented arm. In the image, the retentive element is a single narrow bar aligned with the tooth’s long axis, extending toward the undercut without a broad crossbar or extra components. This clean, straight retentive arm sets it apart from a T-bar clasp, which would show a horizontal crossbar at the end, and from an RPI design, which would include a rest and a proximal plate in addition to the retentive arm. A wrought wire combination clasp would show bent wire segments rather than a single rigid bar. Therefore, the setup shown is an I-bar clasp.