Direct Retainers

Which of the following is NOT a force that can act to displace a removable partial denture from the tissues?

• a) Gravity acting against a maxillary prosthesis

• b) The action of adherent foods on opening of the mouth

• c) Forces of occlusion directed towards the supporting teeth

• d) Functional forces acting across a fulcrum to unseat the prosthesis

What is the primary function of a direct retainer in a removable partial denture?

• • a) To provide support for the denture base

• b) To resist displacement of the prosthesis away from basal seat tissue

• • c) To connect the denture base to the major connector

What are the two means by which sufficient retention is provided for a removable partial denture?

According to the principle of encirclement, what is the minimum degree of tooth circumference that must be engaged by a clasp assembly?

Which of the following is NOT a principal form of extracoronal retainer?