1. Minor connector
   1. Connecting link btw major connector or base of removable dental prosthesis & other units of prosthesis such as clasp, indirect retainers, occlusal rests or cingulum rests
      1. Passive retention in Cast partial denture is provided by "Guiding planes"
   2. Functions
      1. Joins major connector with other components
      2. Transfer of stresses to the abutment teeth
      3. Transfer the force of other components of denture to major connector
   3. Requirements
      1. Should be Rigid in all cases
         1. ▪︎Except in case of Approach arm of bar clasp where flexibility is needed
      2. Strong butt joint with major connector; it leaves the major connector abruptly
      3. Should have triangular cross section with thickest portion near lingual line angle & thinnest near buccal line angle
      4. In cases of mandibular distal extention situation it should extend 2/3rds the length of edentulous ridge
   4. Types
      1. 1. Clasp assembly minor connector
         1. 2 types :- ▪︎Located on proximal surfaces of teeth adjacent to edentulous space ▪︎If clasp assembly is not placed adjacent to edentulous space, minor connector is present between 2 teeth
      2. 2. Indirect retainer or auxiliary rest minor connector
         1. ▪︎It connects indirect retainer & auxiliary rest to major connector
      3. 3. Denture base minor connector
         1. Latticework construction
            1. ▪︎Provides strongest attachment of acrylic resin ▪︎Easy to reline
         2. Mesh construction
            1. ▪︎Indicated : when multiple teeth are to be replaced ▪︎Drawback : doesn't allow easy flow of acrylic during packing. The increased pressure during packing may displace the framework ▪︎It also provides less strong attachment for acrylic compared to lattice
         3. Bead, wire or nail head construction
            1. ▪︎Indicated : in tooth supported dentures where frequent relining & rebasing are not required ▪︎More hygienic
      4. 4. Approach arm minor connector
         1. ▪︎Serves as approach arm for bar clasp ▪︎Supports the direct retainer & engages the undercut from gingival margin
2. Indirect retainers
   1. The component of partial removable dental prosthesis that assists direct retainer in preventing displacement of distal extention denture base in occlusal direction
   2. Forms
      1. Auxiliary occlusal rest
         1. ▪︎Most frequently used ▪︎Located on occlusal surface as far as from distal extention base
      2. Canine rests
         1. ▪︎Indication - When mesial marginal ridge of 1st premolar is close to fulcrum line
      3. Canine extension from occlusal rests
         1. ▪︎Finger like extension from premolar rest is placed on lingual slope of ad ▪︎Indication - When 1st premolar must also act as primary abutment
      4. Cingulum bars & linguoplates
      5. Modification areas
      6. Rugae support
   3. Indirect retainers are placed
      1. On the opposite side of arch as far from fulcrum line as possible
      2. Greater the distance btw fulcrum line & indirect retainer, more effective it'll be
   4. Other key points
      1. Indirect retainer in bilateral distal extention act as Class II lever
      2. Although indirect retention is required in all classes of RPD. However, Class I, II, & long span Class IV arches specially require indirect retention
      3. Reciprocal arm serves mainly to : Give indirect retention
      4. Indirect retainer should resist rotatory forces acting about a fulcrum lines
   5. Denture base
      1. The part of RPD that rests on the basal seat & to which teeth are attached
      2. 3 types
         1. Acrylic
            1. Indications ▪︎Only for interim or temporary dentures
         2. Combination of metal - acrylic
            1. Indications ▪︎Distal extention RPD but can be used with any classification ▪︎When denture teeth are indicated as replacement teeth
         3. Metal
            1. Indications ▪︎Tooth supported dentures ▪︎Reduced interocclusal space ▪︎High occlusal forces - deep bite ▪︎Acrylic allergy