RPD Review Questions

Answer to Question #161


The correct answer is

Incorrect. The tip of the clasp would lie in front of the axis of rotation and the cast clasp has minimal flexibility.

Correct. You must use a distal rest because of the angulation of the tooth. Otherwise the guide plate will pre-empt the planned mesial rest and will act like a rest on an inclined plane. Attempts to physiologically relieve the guide plate would result in a space between the guide plate and the distal proximal surface of the tooth creating an unacceptable food trap. Once you have decided to use a distal rest, you must use a clasp with maximum flexibility (WW).

Incorrect. Because of the tilt of the tooth, the distal guide plate will pre-empt the mesial rest and will act like a rest on an inclined plane. The I-bar would now be a cast clasp in front of the axis of rotation.

Incorrect. The I-bar would be a cast clasp in front of the axis of rotation.