Prostho (major connectors)

• What is the primary function of major connectors in prosthodontics?

  To connect components of the partial denture from opposite sides.
• What are the three main functions of major connectors?

  Support, stability, and retention.
• What provides support in a maxillary major connector?

  The palate and alveolar ridge.
• What provides support in a mandibular major connector?

  The buccal shelf and retromolar pad.
• How does stability in dentures relate to the height of the ridge?

  Stability is influenced by the height of the ridge and depth of the vestibule.
• What is the role of retention in dentures?

  Retention is the resistance to vertical dislodging forces.
• What is adhesion in the context of denture retention?

  Adhesion is the attraction of unlike molecules, such as saliva to tissues.
• What is cohesion in denture retention?

  Cohesion is the clinging of like molecules, such as saliva to saliva.
• How does surface tension contribute to denture retention?

  Surface tension is a combination of adhesion and cohesion forces that maintain film integrity.
• What are the components of a removable partial denture (RPD)?

  1. Major connectors
  2. Minor connectors
  3. Rests
  4. Direct retainers
  5. Stabilizing or reciprocal components
  6. Indirect retainers
  7. One or more bases supporting replacement teeth
• What is the function of unification in major connectors?

  Unification allows all components to act as one unit.
• Why is rigidity important in major connectors?

  Rigidity is important to dissipate functional forces and distribute loads to abutment teeth.
• What can happen if a major connector is too flexible?

  It may cause traumatic damage to periodontal support of abutment teeth.
• Where should major connectors be located to avoid tissue interference?

  They should be free of movable tissue and avoid impingement of gingival tissue.
• What is the recommended relief distance for maxillary major connectors from the marginal gingiva?

  6 mm from the marginal gingiva.
• What is the recommended relief distance for mandibular major connectors from the marginal gingiva?

  4 mm from the marginal gingiva.
• What is the minimum vertical height for a finished lingual bar major connector?

  At least 4 mm for strength and rigidity.
• What are the requirements for major connectors?

  1. Rigid for stress distribution
  2. Non-interference with soft tissues
  3. Avoid food entrapment
  4. Unobtrusive design
• Why is rigidity necessary for major connectors?

  To ensure that the partial denture functions as one unit.
• What materials are preferred for rigidity in major connectors?

  More rigid alloys like chrome-cobalt are preferred over gold alloys.
• What should be avoided to prevent food entrapment in major connectors?

  Margins of the connectors should be located at prescribed distances from the free gingival margin.
• What happens if a major connector fails?

  It may lead to trauma to the periodontal ligament and injury to the residual ridge.
• What is the minimum distance for the border of a maxillary major connector from the gingival margin?

  At least 6 mm from the gingival margin.
• How should the anterior borders of maxillary major connectors be positioned?

  They should be hidden in a valley between rugae.
• What are the types of maxillary major connectors?

  1. Single palatal strap
  2. AP strap
  3. Palatal plate
  4. U-shaped palatal connector
  5. Single palatal bar
  6. Anterior-posterior palatal bars
• What is the minimum width for a single palatal strap?

  Minimum width of 8 to 10 mm.
• What is the snow-shoe principle in denture design?

  The total area covered by the base should be as large as possible to distribute the load.
• What are the advantages of a single palatal strap?

  Great resistance to bending and twisting with little interference with normal tongue action.
• What is a disadvantage of a single palatal strap?

  Patients may complain of excessive palatal coverage.
• Why should the anterior border of a single palatal strap not extend beyond the junction of the hard and soft palate?


  Because it may cause the denture to dislodge.
• What are the indications for an anterior-posterior palatal strap?

  Class I & II arches with excellent abutment and residual ridge support.
• What is the shape of an anterior-posterior palatal strap?

  Parallelogram in shape.
• What is the minimum clearance from gingival crevices for an anterior-posterior palatal strap?

  8 mm clearance from gingival crevices.
• What is the primary indication for a palatal plate connector?

  Primarily indicated in Kennedy Class I arch forms with poor support from the residual ridge.
• What is a characteristic of a U-shaped palatal connector?

  It lacks rigidity and does not provide good support characteristics.
• What is the disadvantage of increased thickness in a U-shaped palatal connector?

  It can hinder tongue movement.