RPD Review Questions

Answer to Question #147


The best answer is

Incorrect. A true statement but not the BEST answer. Rest seat preparations should be rounded and "spoon-shaped". This is particularly important in extension RPDs where the prosthesis needs to be able to rotate around the rests during functional movement.

Incorrect. A true statement but not the BEST answer. The width of the occlusal rest seat is at least 1/3 the total width of the occlusal surface but more often approaches 1/2 of the distance between the buccal and lingual cusp tips.

Incorrect. A true statement but not the BEST answer. Rest seat preparations must be at least 1 mm deep.

Correct. Since 1, 2, and 3 are all true, #4 is the BEST answer.