What is the retention mechanism difference between a fixed partial denture and a removable partial denture?

• A. FPD retention uses clasps and attachments for retention.
• B. RPD retention is cemented to abutments.
• C. FPD retention is independent of tooth preparation.
• D. FPD is cemented and relies on tooth preparation and abutments for passive retention; RPD relies on clasps, attachments, or reciprocating components and tissue support.

Answer: (D)

Retention mechanisms for fixed partial dentures versus removable partial dentures differ. A fixed partial denture is cemented to prepared teeth and relies on tooth preparation and abutments for passive retention—the fit of the crowns and the cement create a secure, non-removable connection. A removable partial denture, by contrast, uses removable components such as clasps, attachments, or reciprocal elements and gains stability from the surrounding tissues for support. So the best answer states that a fixed partial denture is cemented and relies on tooth preparation and abutments for passive retention, while a removable partial denture relies on clasps, attachments, or reciprocating components and tissue support.