Removable Partial Denture Principles — Worksheet MCQs

Which feature of a direct retainer primarily prevents horizontal displacement?

• Occlusal rest

• Retentive arm

• Reciprocal arm

• Minor connector

• Denture base

The main function of an indirect retainer in a distal extension RPD is to:

• Prevent vertical occlusal forces

• Support the major connector

• Reduce rotational displacement around the fulcrum line

• Retain the prosthesis in the anterior segment

• Stabilize minor connectors

A distal extension RPD rotates around a fulcrum line passing through:

• Two rests on posterior abutments

• Anterior teeth only

• Lingual plates

• Maxillary canine tips

• Occlusal rests on the mandibular ridge

The most effective way to relieve tissue trauma from an overextended flange is:

• Polishing the surface

• Border adjustment or trimming

• Adding more acrylic

• Increasing occlusal thickness

• Using softer teeth

In a Kennedy Class I RPD, stress-breaking elements are necessary because:

• They improve esthetics

• They allow limited base movement without stressing abutments

• They increase vertical dimension

• They reinforce the denture base

• They prevent food impaction

Occlusal rests are designed primarily to:

• Improve esthetics

• Support vertical occlusal forces

• Engage retentive undercuts

• Reduce muscle-induced displacement

• Limit minor connector rotation

Rest seat preparation should:

• Be shallow to reduce stress

• Conform to the natural tooth contour

• Cover the entire occlusal surface

• Avoid contacting enamel

• Reduce horizontal occlusal clearance

The ideal height of a clasp retentive tip from the height of contour is:

• At the height of contour

• 0.25–0.50 mm below the height of contour

• 1 mm above the height of contour

• At the gingival margin

• Midway along the tooth axis

When an RPD exhibits tipping of abutments, the most likely cause is:

• Excessive acrylic thickness

• Improper clasp design

• Deep occlusal rests

• Lingual plate length

• Poor shade selection

Minor connectors primarily function to:

• Provide vertical support

• Connect clasp assembly to the major connector

• Replace missing teeth

• Increase occlusal vertical dimension

• Improve esthetics