Connnectors In FPD
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Connnectors In FPD

Miscellaneous

Fixed Partial Denture

Connnectors In FPD 

 

Connector is the portion of FPD that unites the retainer(s) and pontic(s),


It can be of 2 types:

  • Rigid connectors
  • Non rigid connectors
  1. Tenon-Mortise connectors   {Key-Keyway)
  2. Loop connectors
  3. Split pontic connectors
  4. Cross pin and wing connectors

  • Rigid connectors:

  1. They are used to unite retainers and pontics in a fixed - fixed denture.
  2. These connectors are used when the entire load on the pontic is to be transferred directly to the abutments.
  3. A rigid connection can be made by casting as part of a multiunit wax pattern or by soldering.

The connector should be circular in form and should occupy the contact area.

  1. To be biologically and functionally acceptable, the soldering joint between pontics and connector should be longer cervico-occlusally and narrower buccolingually.
  2. When both premolars are missing, the connectors in FPD used to replace them should be rigid both on the canine and the first molars,

  • Non-rigid connectors / precision attachments / stress breakers:

  1. These are indicated where a single path of insertion cannot be achieved due to non-parallel abutments,
  2. Normally keyway should be on the distal surface of mesial abutment and key on mesial surface of pontic. This arrangement encourages the mesial drift to seat the key into the keyway.
  3. If the stress breaker is present on the distal abutment, occlusal forces tend to unseat the key from the keyway.
  4. In case of pier abutment, the keyway is placed on the distal surface of pier abutment and key on mesial surface of distal pontic.
  5. The distal segment, with the key is cemented immediately after cementation of the mesial segment. A distal stress breaker seats the key into the keyway when subjected to occlusal forces while a mesial stress breaker unseats the key from the key way.
  6. The path of insertion of the key into the keyway should be parallel to the path of insertion of the retainer not involved with the keyway.
  7. Since the non rigid connector restricts the interdental space, they are used only with ample embrasure space.

Indications of non rigid connectors:

  • Short span FPD replacing single tooth,
  • Retainers cannot be prepared to draw together without excessive tooth reduction.
  • Tilted FPD abutment
  • Pier abutment

 

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