Removable Prosthodontics II: RPD Framework Considerations and Design

This set of vocabulary flashcards covers the fundamental components, biomechanical principles, and design systematic steps for Removable Partial Denture (RPD) frameworks based on Lecture 7 of Removable Prosthodontics II.

Rests

Components of the RPD framework that are part of the clasp assembly and provide support.

Tooth supported RPD

A denture supported mesially and distally by teeth (Class 3 and 4) which are supported by the periodontal ligament in the bone.

Tooth-tissue supported RPD

A denture involving distal extension bases (Class I and II) where support is shared between teeth and the residual ridge.

Compressibility difference

The difference in movement between teeth ($0.25\,mm$) and mucosa ($2\,mm$) which generates rotational movement and force on abutment teeth.

Altered cast technique

A functional impression technique used to reduce the movement of a distal extension base with displaceable or compressible tissue.

RPI system

A clasp system designed to eliminate lever action (stress breaking) on the abutment tooth in distal extension cases.

Combination clasp

A clasp consisting of a cast reciprocating arm and a wrought wire retentive arm used to reduce stress on abutments due to its flexibility.

Indirect support

Provided by the retentive arm of the clasp or rests positioned as far as possible from the fulcrum line.

Fulcrum line

An imaginary line passing through the rests of the most distal abutments or those closest to the edentulous area.

Indirect retention

Retention provided by components (such as rests) positioned as far as possible from the clasp line passing through the clasp tips.

Ring clasp

A clasp design used on bounded teeth, such as a mesially drifted molar, to prevent drifting and position the tip away from the cheek.

Stability

Resistance to movement provided by the major connector, minor connectors, and clasps, especially challenging in severely resorbed or flat ridges.

Primary stress bearing area

An area like the hard palate in the maxilla that provides a significant amount of support, reducing rotation movement compared to the mandible.

Bracing and reciprocation

Resistance to lateral movement provided by reciprocal arms, minor connectors, and the flanges of the RPD that engage the vertical wall of the ridge.

Major connector

The component of the RPD that joins the parts of the denture on one side of the arch to those on the opposite side; examples include the palatal plate, lingual bar, and lingual plate.

Post-dam area

An area used in Kennedy Class I cases to increase retention and hide the posterior edge of the denture.

Secondary abutments

Teeth not immediately adjacent to the edentulous area that are utilized by increasing the number of rests to increase support.

Selective pressure technique

An impression technique used to utilize the primary support area and provide relief to specific relief areas.

Saddles

The part of the RPD that carries the prosthetic teeth and covers the edentulous ridge.

Resistance arm

A component whose length and position (farther from the support axis) are optimized to increase indirect support.