Metal Framework Try in, Sectioning and Soldering “Connectors”-Serag

Question 1

What is the sequence to make clinical adjustments when trying in framework for fixed prosthesis final product?

Answer 1

• Proximal Contacts
• Internal Fit
• Stability
• Marginal Integrity
• Occlusion
• External Contours
• Surface finish

Question 2

Internal Fit: Internal Surface

Answer 2

• Identify and remove “positive” Contacts
• Steps:
  
  • Fit Checker, disclosing wax
  • Burn/bleed Through:
    
    • nodules, internal line and point angles
  • Selective Grinding:
    
    • # ½ and #1 round carbide
  • Indiscriminate removal unacceptable
  • remove slight excess
  • repeat steps

Question 3

Marginal Adaptation: Negative vs Positive Defect

Answer 3

• Negative Defect:
  
  • ex: short or open margin
  • Two-way catch
    
    • remake
    • additional visit for new impression
• Positive Defect:
  
  • ex: Overextension
  • one-way catch
    
    • stone or rubber wheel
    • if margin damaged=remake

Question 4

Stability & Retention

Answer 4

• Rock
  
  • movement in Facial-lingual direction
• Rotate:
  
  • movement in CW/CCW direction

Question 5

What is Soldering?

Answer 5

• Joining of 2 metals through fusion of a filler metal
• bond is created by wetting the parent metals
  
  • not melting (welding)
• can be done in dental office

Question 6

What is welding?

Answer 6

• direct fusion of 2 metals by melting

Question 7

What are the physical requirements for soldering?

Answer 7

• Resistant to tarnish and corrosion
• Fusion temperature:
  
  • 90-180F below melting point of metal that is being soldered
• Free flowing
• Resistant to pitting
• at least as strong as the alloy being soldered
• color compatible to the alloy being soldered

Question 8

When choosing a solder, what do you need to know?

Answer 8

• Need to know:
  
  • fusion temperature of parent metal
  • gold content of parent metal
• If you know the manufacturer of the alloy, they will have a suggested solder

Question 9

Soldering Flux

Answer 9

• control oxidation of the alloys
• increase the flow and wetting properties of the solder
• allows the fluid solder to wet the uncontaminated parent alloy

Question 10

Soldering Anti-Flux

Answer 10

• prevent the flow of solder into critical areas
  
  • margins
  • occlusal anatomy

Question 11

What are common anti-flux material?

Answer 11

• Polishing rouge
• Graphite (lead pencil)

Question 12

Common flux materials?

Answer 12

• borax and silica compounds

Question 13

Steps in Soldering FDP

Answer 13

• Section the FPD
  
  • 0.2mm
• Fully Seat each retainer
  
  • X-ray
• Unite and index the segments
• Prepare the surfaces for soldering
• Invest
• Flush and trim the investment block
• preheat the investment block
• solder
• divest
• pickle