Which clasp setup is 10 mm long from the origin on distal extension partial denture?

Which clasp setup is 10 mm long from the origin on distal extension partial denture?

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

Answer: (A)

In distal extension partial dentures, a simple, discreet direct retainer is often used to resist dislodgement without creating excessive lever forces on the abutment. The I-bar fits this role by providing a slim retention arm that engages the tooth’s undercut and extends about 10 mm from its origin. That length balances enough engagement with the undercut to hold the denture securely while minimizing leverage that could pry the tooth during function. The other clasp options have different shapes and mechanical implications: the T-bar is bulkier and typically requires a different projection; wrought wire combinations rely on flexible wire and aren’t defined by a fixed 10 mm length; and the RPI system is a broader design approach that includes an I-bar as part of its setup but isn’t characterized by this single fixed dimension. So the 10 mm I-bar is the best fit for this scenario.

In distal extension partial dentures, a simple, discreet direct retainer is often used to resist dislodgement without creating excessive lever forces on the abutment. The I-bar fits this role by providing a slim retention arm that engages the tooth’s undercut and extends about 10 mm from its origin. That length balances enough engagement with the undercut to hold the denture securely while minimizing leverage that could pry the tooth during function. The other clasp options have different shapes and mechanical implications: the T-bar is bulkier and typically requires a different projection; wrought wire combinations rely on flexible wire and aren’t defined by a fixed 10 mm length; and the RPI system is a broader design approach that includes an I-bar as part of its setup but isn’t characterized by this single fixed dimension. So the 10 mm I-bar is the best fit for this scenario.