Direct Filling Gold Question And Answers

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Direct Filling Gold Short Essays

Question 1. DFG (Direct Filling Gold).
Answer:

DFG (Direct Filling Gold):

Direct Filling Gold Definition:

  • Direct gold is a gold restorative material that is manufactured for compaction directly into prepared cavities

Direct Filling Gold Indications:

  • Class 1 cavities Small carious lesions in pit and fissures of posterior teeth
  • Class 5 carious lesions
  • Class 3 cavities proximal surfaces of anterior teeth
  • Class 2 restoration of small cavitated proximal surfaces of posterior teeth
  • Class 6 Incisal edges or cusp tips
  • A defective margin of cast metal restoration

Direct Filling Gold Contraindications:

  • Very large pulp chambers
  • Severely periodontally weakened teeth with questionable prognosis
  • In handicapped patients
  • Root canal-filled teeth

Direct Filling Gold Classification:

1. Foil:

  • Sheet
    • Cohesive
    • Noncohesive
  • Ropes
  • Cylinders
  • Laminated foil
  • Platinized foil

2. Electrolytic Precipitate:

  • Mat gold
  • Mat foil
  • Gold calcium alloy

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Question 2. Types Of Gold.

Answer:

Types Of Gold:

1. Gold Foil Oldest Form:

Types:

1. Sheets Size 10 x 10 cm

  • Thickness 1.5 micron
  • No.3 weighs 3 gm
  • Too large for use in preparation

2. Gold Foil Cylinder

  • Uses noncohesive gold
  • Uses % and 1/8 of a sheet of gold

3. Gold Pellets

  • Are annealed before the formation
  • Stored in a gold foil box along with a cotton dipped in 18% ammonia

4. Platinized Gold Foil

  • Platinum content in foil is 15%
  • Increased hardness
  • Used for restoration of cusp tips and incisal edges

5. Corrugated Gold Foil.

  • Paper placed between foil gets burnt and charred

4. Laminated Gold Foil:

  • More resistant to applied forces

2. Crystalline Gold

1. Mat Gold

  • Electrolytically precipitated type
  • Used for building up of internal restoration

2. Mat Foil

  • No need to veneer the restoration

3. Electralloy

Increased hardness and strength of gold by adding minute quantities as Calcium

Improved handling properties

4. Powdered Gold

  • Size 15 microns
  • Difficult to handle
  • Does not require very sharp line angles and point angles.

Direct Filling Gold

Question 3. Mat Gold.

Answer:

  • Electrolytically precipitated

Mat Gold Preparation:

  • Sinter pure gold in the oven
  • Heat slightly below its melting point

Mat Gold Result:

  • Spongy, loosely arranged crystalline structure
    • Available in form of strips
    • Can be used plain/sandwiched in gold foil
  • Mat Gold Use: Building up of internal restoration
  • Mat Gold Advantage: Easily compacted
  • Adapted well

Question 4. Condensation of DFG.

Answer:

Condensation Of DFG:

Condensation Of DFG Aims:

  • Formation of cohesive mass
  • Adaptation to the preparation margins
  • Prevent voids formation
  • Increases strength and hardness of restoration

Condensation Of DFG Technique:

  • Place the gold piece in the corner of the preparation
  • Start malleting in the center of the mass
  • Condense at 45o to walls and floor for maximum adaptation
  • Next condense at 90° to the previous layer to prevent displacement of already condensed pieces
  • Each time the condenser should overlap the half of previous step for reducing voids formation
  • This is called stepping

Direct Filling Gold Stepping of condenser during condensation of direct gold

Direct Filling Gold Tie Formation

Direct Filling Gold Bamking of the walls

Question 5. Annealing/Degassing.

Answer:

Annealing:

  • Annealing involves the removal of the volatile protective coating present on a pure gold surface
  • Used for noncohesive gold, as a layer of ammonia is present over it to prevent the formation of the oxide layer and contaminate gold

Annealing Methods:

1. Using Alcohol Flame:

  • Bulk Method:
    • Place mass of gold in mica tray and heat over flame up to 650700°C
    • Less time required
    • Risk of overheating
  • In The Piece Method;
    • Hold small pieces over a blue flame of alcohol and heat until the gold becomes dull red
    • Less wastage
    • Time consuming

2. Electric Annealer:

  • Gold is heated for 10 minutes at 850°F
  • Then cooled for placing in the prepared tooth

Direct Filling Gold Short Answers

Question 1. Preparation of Pure gold foil.

Answer:

Preparation Of Pure Gold Foil:

  • Gold foil are cut into sheets
  • These sheets are separated by papers
  • These are heated together
  • 20 such papers are consist in the book
  • These sheets are cut into different sizes and are available in different weight

Question 2. Properties of DFG (Direct Filling Gold)

Answer:

Properties Of DFG (Direct Filling Gold):

  • Direct Filling Gold soft, malleable, and ductile
  • Direct Filling Gold does not get oxidized
  • Direct Filling Gold is yellowish, metallic in color
  • Direct Filling Gold get fuses at 1063oC and boils at 2200oC
  • The density of gold is 1919.3 g/cm2
  • Direct Filling Gold hardness is 25 BHN
  • Direct Filling Gold coefficient of thermal expansion is 14.4 x 106/oC which is more than that of a tooth
  • Direct Filling Gold is the noblest of all metals
  • Direct Filling Gold has high thermal conductivity
  • Direct Filling Gold can be cold welded
  • Direct Filling Gold results in good marginal integrity

Question 3. Electrically.

Answer:

Electrically:

  • The newest form of DFG

DFG Preparation:

  • Electrolyte it along with the addition of minute quantities of calcium
  • The resultant crystalline structure is sandwiched between two gold foils

DFG Advantages:

  • Improved handling properties
  • Produces the hardest surface
  • Increased strength and hardness

Question 4. Gold Foil.

Answer:

Gold Foil:

Gold Foil Types:

1. Sheets Size 10 x 10 cm

  • Thickness 1.5 micron
  • No.3 weighs 3 gm
  • Too large for use in preparation

2. Gold Foil cylinder

  • Uses noncohesive gold
  • Uses % and 1/8 of a sheet of gold

3. Gold Pellets

  • Are annealed before the formation
  • Stored in a gold foil box along with a cotton dipped in 18% ammonia

4. Platinized Gold Foil

  • Platinum content in foil is 15%
  • Increased hardness
  • Used for restoration of cusp tips and incisal edges

5. Corrugated Gold Foil

  • Paper placed between foil gets burnt and charred

6. Laminated Gold Foil

  • More resistant to applied forces

Direct Filling Gold Viva Voce

  1. All types of DFG except non corrosive gold require degassing before use
  2. Underheating fails to render the gold surface pure
  3. Overheating makes the gold more brittle
  4. Poor resistance form can result in tooth fracture
  5. Improper retention form results in loose restoration
  6. Forces of condensation should be at 45° to the cavity walls and floors
  7. Forces of condensation must be at 90° to previously condensed gold

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