RPD Review Questions

Answer to Question #30


The correct answer is

Incorrect. Wrought wire clasps are commonly used on terminal abutments for extension RPDs.

Correct. Wrought wire clasps should not be used as embrasure clasps. It is difficult to bend the clasp accurately through the embrasure and the slightest nick in the wire or wear from occlusion will predispose the clasp to breakage in the area where it passes over the occlusal surfaces of the teeth.

Incorrect. Wrought wire clasps are frequently used on teeth that have indirect retainers on them. A good example would be a class II modification 1 RPD where the anterior abutment on the tooth-supported side has a rest that acts as an indirect retainer. If this tooth also has a clasp on it, the clasp should be wrought wire because the tooth lies bodily in front of the axis of rotation.

Incorrect. Answer 4 is incorrect because answer 3 is incorrect.