Provide definitions and explain the functions of the following:-

Provide definitions and explain the functions of the following:-

1. Support

   • Definition
     • - Denture Support is the resistance of the denture against movement toward the tissue.
   • Functions
     • - To support denture saddles against vertical forces and to transmit these forces to the natural teeth. - To transmit some proportion of the lateral forces to the natural teeth and to provide a certain amount of bracing. - They may improve the occlusion - They may act as indirect retainers.

2. Reciprocation of clasps

   • Definition
     • - A component of the clasp assembly specifically designed to provide reciprocation by engaging a reciprocal guiding plane; it counteracts the action of the clasp during removal and insertion of the removable partial denture.
   • Functions
     • - Resists lateral movement of the prosthesis. - Resists potential orthodontic movement of the abutment tooth generated by the retentive arm during placement and removal of the rpd.

3. Major connectors

   • Definition
     • - The part of a removable partial denture that joins the components on one side of the arch to those on the opposite side.
   • Functions
     • - Connectors are strong, rigid and ensure a wide load distribution. - Connects all parts of the denture together, and join saddles. - There are 4 types of major connectors; Palatal and lingual plates, Anterior Posterior and Mid-palatal bar, Lingual bars, and Buccal/labial bars

4. Indirect retainers

   • Definition
     • - The component of a removable partial denture that assists the direct retainer(s) in preventing displacement of the distal extension denture base by functioning through lever action on the side opposite of the fulcrum line when the denture base moves away from the tissues in pure rotation around the fulcrum line.
   • Functions
     • - Indirect retention attempts to reduce the continual loading and unloading of tissues by preventing movement of the denture base away from the mucosal tissues. - Anteriorly placed components prevent rotation most commonly a rest. - Bars, plates, onlays and supports can also act as indirect retainers

5. Rests

   • Definition
     • - Any component of a partial denture on a tooth surface that provides vertical support.
   • Functions
     • - Rests serve to support the position of a partial denture and to resist movement toward the tissue. - They serve to transmit vertical forces to the abutment teeth and to direct those forces along the long axes of the teeth.

6. Saddles

   • Definition
     • - The tooth bearing part of the denture
   • Function
     • - The saddle function is to replace lost alveolar tissue and carry artificial teeth. - A saddle covers the maximum amount of mucosal tissue as is functionally possible to minimise the load through the mucosa and spread the load more widely. - It should be contoured to adopt the shape of the natural surrounding tissues.

7. Retention

   • Definition
     • - Denture Retention is the resistance of the denture against movement away from the tissues, or resistance to vertical displacing forces.
   • Function
     • - CLASPS and PRECISICION ATTACHMENTS are used to provide positive retention. These are DIRECT RETAINERS. - Direct retainers engage an undercut area or an abutment tooth so as to resist vertical displacement. Such undercuts, of course, are relative to the path or insertion.