Framework Try-In Flashcards
Prepared master casts are duplicated to produce…
an exact copy of master cast in investment material (refractory cast)
Framework pattern will be fabricated on the __________ cast using wax
refractory
An impression Using _____________________ is made of the block out on the master cast to create the refractory cast
reversible hydrocolloid (Agar)
TIPS FOR THE FRAMEWORK TRY IN:
▪The completed RPD must be passive.
▪Should not exert forces on the teeth or soft tissues.
▪The tip of each retentive clasp should lie passively in a measured undercut.
Block Out and Relief Wax is Placed on the __________ CAST
MASTER
Master cast with block out and relief wax is duplicated twice and each is used for…
One is Poured in Stone and one in High Heat Refractory Material
The wax-up of the RPD framework is completed on the __________ cast.
refractory
The refractory cast is usually _______, and the material is ________________.
white
high heat investment
The wax-up of the RPD framework is completed on the ____________ cast
refractory
Laboratory returns the framework on the ____________ cast
duplicate or “fitting” cast
Difference between master cast and duplicate cast
The dentist should be the first to evaluate the fit on the master cast including:
▪ Path of placement
▪ Action of retentive & reciprocating arms
▪ Areas of interference/Scraping of cast
▪ Accuracy of seating
Dentist should evaluate the framework on the __________ cast
master
Evaluate ____________ surfaces for proper finish and construction
external/internal
What do you need to check the fitting, occlusion, and intraoral fit of framework?
▪Good light
▪Magnification
▪Mirror and explorer
How should the framework fit to the teeth?
▪Position direct retainers over the abutments
▪Place fingers over rests and push along the path of placement
▪The framework should move smoothly with minimal resistance
▪Balanced resistance should exist
What happens if there is not balanced resistance?
▪ A more rigid retentive tip on one abutment than another will cause tilting
▪ If the framework is not fully seated, the retainers will not be passive and will exert forces against the teeth
What should you evaluate on the external surface of RPD?
▪ Rests
▪ Major Connector
▪ Minor Connectors
▪Direct Retainers
▪Indirect Retainer
▪External Finish Lines
What should the finish of the intaglio surface look like?
▪ Surface should be smooth and free from irregularities (no bubbles, blebs, and artifacts)
▪ Surface is not highly polished
What are the possible causes for framework misfit?
▪ Faulty impression technique
▪ Faulty casts
▪ Tooth movement
▪ Casting inaccuracy
What are ways that the impression could be faulty?
▪ Lack of uniform thickness of impression material
▪ Intraoral distortion due to tray movement
▪ Extraoral distortion due to faulty handling
What are ways that the casts could be faulty?
▪ Improper water to powder ratio
▪ Improper spatulation
▪ Failure to use double pour cast formation technique when making impressions in irreversible hydrocolloid
What issues can you have with tooth movement from impression to framework try-in?
▪ Tooth movement due to occlusal disharmonies/ periodontally involved teeth
✓Mesially inclined mandibular molars
✓ Lone standing premolars
▪ Recent extractions
What are the teeth that are likely to have movement from impression to framework try-in?
✓Mesially inclined mandibular molars
✓ Lone standing premolars
What can cause casting inaccuracy?
▪ Expansion of the investment
▪ Shrinkage of Ni-Chrome alloys is 2.2 to 2.4% during casting
How do you fit the RPD frameowrk intraorally?
▪Adjust the framework
▪Adjust the direct retainers
▪Adjust the occlusion
What are common ares of framework interference?
▪ Internal surfaces of direct retainer shoulders
▪ Internal surfaces of direct retainer bodies
▪ Internal surfaces of minor connectors
▪ Interdental papilla areas
other areas that cause interference
▪ Reciprocating arms
▪ Lingual plating
▪ Soft tissue
Shrinkage of Ni-Chrome alloys is _______% during casting
2.2 - 2.4
What are the disclosing materials that can be used to identify interferences?
- NEY Spray
- Occlude
- Kerr Disclosing Wax
How do you use disclosing materials to located interferences?
▪Dry the framework
▪Place a thin layer of indicating material
▪ Insert framework along path of insertion
▪ Apply finger pressure
▪ Remove the framework and note areas of interference
▪ Adjust area of interference with a small bur or stone
▪ Wipe framework clean and repeat procedure until the framework is seated
The framework should seat without a _____
click
What are other ways to locate interferences in addition to disclosing material?
▪Evaluate contact of direct retainers and reciprocating arms
▪Check for wedging - modification spaces
▪Adjust the occlusion
Assure that the _______ relationship exists in centric relation (occlusion) and eccentric functional movement with the framework in the mouth, as exists between the teeth when the framework is not present.
same
Adjust the occlusion on the RPD framework for _____________
centric relation
What should you check when adjusting for centric relation?
✓Maintain bulk of rests for strength
✓Opposing teeth may need modification
