Partial dentures Flashcards
(27 cards)
What is the primary purpose of a removable partial denture (RPD)?
To replace missing teeth and restore function, esthetics, and prevent the migration of remaining natural teeth.
What are the main components of a removable partial denture?
Framework (metal or acrylic), artificial teeth, and retainers (clasps) and/or connectors (major and minor).
What is the function of the major connector in an RPD?
To join the components of the partial denture located on one side of the arch to opposite side, providing stability and stress distribution.
Give examples of maxillary major connectors.
Connectors should be 6mm away from gingival margins
Palatal plate - maximum tissue support.
Horseshoe (U-shaped) connector - palatal tori
Anterior-posterior palatal strap
Palatal strap
Give examples of mandibular major connectors.
Connectors should be 4mm away from gingival margins.
Lingual bar - most common, need lingual sulcus depth of >7mm, contraindicated in lingual tori.
Lingual plate - <7mm, additional tooth loss expected, suitable in presence of lingual tori.
What is the function of a minor connector in an RPD?
To connect the major connector to other components of the denture, such as clasps, indirect retainers, and denture bases.
What is the purpose of a direct retainer (clasp) in an RPD?
To provide retention by engaging an abutment tooth, resisting vertical dislodgement of the partial denture.
What are the basic components of a circumferential clasp?
Retentive arm, reciprocal arm, rest, and connector.
What is the function of the rest seat on an abutment tooth?
To provide support for the partial denture, directing occlusal forces along the long axis of the abutment tooth and preventing tissueward movement of the clasp assembly.
Indirect retention when located perpendicular to fulcrum line, resisting rotational forces of denture base away from tissue.
What is the difference between a suprabulge and an infrabulge clasp approach?
Suprabulge: The retentive arm originates above the survey line and engages the undercut from an occlusal direction. Infrabulge: The retentive arm originates below the survey line and approaches the undercut from a gingival direction.
What are some advantages of infrabulge clasps?
Improved esthetics (less metal display), potentially better stress distribution, and reduced interference with occlusion.
What is the purpose of an indirect retainer in an RPD?
To assist the direct retainers in resisting rotational movements of the partial denture base away from the tissues.
Where are indirect retainers typically placed?
As far as possible from the fulcrum line (the imaginary line connecting the most posterior abutment teeth) on the opposite side of the fulcrum line from the extension base.
What is the Kennedy classification system used for in partial dentures?
To classify partially edentulous arches based on the location and number of edentulous areas, aiding in the design of the RPD.
Briefly describe Kennedy Class I.
Bilateral edentulous areas located posterior to the remaining natural teeth.
Briefly describe Kennedy Class II.
A unilateral edentulous area located posterior to the remaining natural teeth.
Briefly describe Kennedy Class III.
A unilateral, natural teeth bounded edentulous area.
Briefly describe Kennedy Class IV.
Single, anterior edentulous area that crosses midline.
What are the objectives of surveying a diagnostic cast for RPD fabrication?
To determine the path of insertion, identify undercuts for retention, locate interfering tooth surfaces, and plan the placement of rests and other components.
What is a guide plane in RPD design?
Parallel vertical surfaces on abutment teeth that are created to provide a definite path of insertion and removal for the RPD and ensure proper seating of components.
What is the purpose of blockout during RPD fabrication?
To eliminate undesirable undercuts on the master cast that would interfere with the insertion and removal of the RPD framework.
What are the advantages of an acrylic resin denture base compared to a metal base?
Better esthetics (can match tissue color), easier to add teeth or reline, and generally less expensive.
What are the advantages of a metal denture base compared to an acrylic resin base?
Increased strength and rigidity, better thermal conductivity, and can be made thinner.
What is the process of relining a partial denture?
Adding new base material to the tissue-fitting surface of the denture to improve its adaptation to the underlying mucosa due to tissue changes over time.
Relining: Adds new material to the existing base. Rebasing: Replaces the entire denture base.
