Movement of three removable partial denture clasp assemblies under occlusal loading

This investigation indicates that the design of the clasp assembly affects the magnitude of movement of the abutment tooth adjacent to an extension base but generally does not affect the direction of movement. Some clasp assemblies (distal rest) moved more than other clasp assemblies (wrought wire or I-bar), and hence, the abutment tooth moved more. The design of the clasp assembly did not seem to affect the magnitude of movement in the apical direction.