RPD Review Questions

Answer to Question #77


The correct answer is

Incorrect. The undercut is not appropriate for an I-bar. The I-bar must be placed just in front of the greatest mesiodistal curvature of the facial surface. In this case, most of the undercut is behind the greatest mesiodistal curvature of the facial surface.

Correct. Most of the undercut is behind the greatest mesiodistal curvature of the facial surface and that is where the retentive tip should be placed. The vertical approach arm must be placed in front of the greatest mesiodistal curvature so that the clasp cannot simply move upward and backward without flexing. If this could happen, the clasp would not be retentive.

Incorrect. A circumferential clasp cannot be used because the undercut is adjacent to the edentulous area (and on the same side of the tooth as the origin of the arm).

Incorrect. Same reason as #3.