DIRECT FILLING GOLD RESTORATIONS IN .ppt

HEALTH

1. DIRECT FILLING
GOLD
DR SAYLI .P. PATIL

2. “Direct gold are those gold restorative materials that are
manufactured for compaction directly into the prepared
cavity”.

3. CLASSIFICATION
A) According to Skinners
Divided into 3 categories
I.Foil – also known as fibrous gold
II.Electolytic precipitate –also known as crystalline gold
III.Powdered gold
I. Foil
a)Sheat
•Cohesive
•Non cohesive
b)Ropes
c)Cylinders
d)Laminated foil
e)Platinized foil

4. II. Electrolytic precipitate
Mat gold
Mat foil
Gold calcium alloy
III. Powdered gold
Encapsulated gold powder

5. B) According to Sturdevent
Direct filling gold is of 6 types
1.Gold foil
2.Platinized gold foil
3.Crystalline gold – 3 forms
a.Mat gold
b.Mat gold wrapped in gold foil
c.Mat gold alloyed with calcium and wrapped in gold
foil (electraloy RV) and powdered gold.

6. Cohesiveness- quality of forming a united whole mass
Softness aids in manipulation
Malleability
Ductility
Hardness in bulk form—Brinell hardness number (BHN)
is 25.
Gold is the noblest of all metals hence does not show
tarnish and corrosion in oral environment.
Tensile strength is 19,000 psi which rises to 32,000 psi
Properties

7. Coefficient of expansion is 14.4 that is near to 11.4, the
coefficient of crown of tooth.
High thermal conductivity.
It is chemically inactive and is not affected by heat,
moisture or most solvent.
Gold can be cold welded at room temperature.
Density of pure gold is 19.3 g/cm3. more the density of
gold, lesser will be the porosity in condensed gold thus
making the restoration long lasting.

8. FACTORS INFLUENCING SELECTION OF
GOLD
Physical condition of the patient
Mentality and will power of the patient
Age
Strength of periodontal membrane and state of development of
the root.
Extent and rapidity of caries and oral hygiene of the patient.
Sensitivity of the dentin
Strength of cavity walls
Character of occlusion
Accessibility of the cavity
Skill of the operator
Esthetic condition

9. Gold foil
Produced by beating or rolling.

10. I. Gold foil
Gold foil is made by beating pure gold into thin sheets
of size 10 × 10 cm (4 × 4 inch). Thickness of gold foil is
1.5 micron. Foils are supplied in books which are
separated by thin paper pages.
It comes in a book of 1/10 or 1/20 ounces. One book
has 12 sheets of common dimension of 4x4 dimension.
No. 4 gold foil weighs 4 grains (0.259gms) and is
0.15µm thick.
No.3 – 3 grains- (0.194gm)- 0.38µm thick.

11. Platinized gold foil
It is made up by placing a sheet of platinum
between two sheets of gold foil and then
hammering till platinized gold is formed. Platinum
content in foil is 15%.
Platinum increases hardness of the restoration.

12. Laminated gold foil
Laminated gold foil is manufactured by
combining 2 to 3 gold foils together.
Corrugated gold foil
Corrugated gold foil is made by putting thin sheets of paper
between gold foil sheets, and igniting them. Paper in between
the gold foil gets burnt and charred leading to corrugated
appearance of gold foil.

13. II. ELECTROLYTIC PRECIPITATE
Mat gold
Precipitated through electrodeposition and it is
accumulated in the form of strips or cones. These
strips are cut by dentist into desired sizes.
Mat gold is placed in a mold at room temperature to
become compelled and is then sintered in an oven.
Advantages: It is sponge type and adapts well to
cavity walls.
Uses: It is used for building up the internal bulk of the
restoration.
Mat Gold

14. MAT FOIL
Mat foil is formed by placing the mat gold between No. 3
or 4 gold foil and then sintering just below melting point
of gold. It is then cut into strips of different sizes.

ELECTRALLOY
It is the newest form of direct filling gold. It is produced by
electrolytic precipitation method. Then this crystalline
structure is sandwiched between two gold foils to
improve the handling properties.

15. III. Powdered Gold or Gold-dent
or Granular Gold
Also known as E-Z gold.
It is blend of atomized and precipitated powder
embedded in a wax-like organic matrix.
It is available in pellets of various sizes which are
enclosed in gold foil wrappers and packed for use.
Prior to its condensation and matrix is burnt away
leaving only pure gold to be packed.

16. GOLDENT
Combination of powdered gold and gold foil.
The ratio is 95% powder to 5% foil. It is
provided in cohesive form.
Advantages:The envelop holds the powdered
particles during condensation, making handling
easier.

17. 1. Incipient carious lesions
Class I lesion in premolar teeth and other accessible developmental
pits.
Class II lesion in premolar teeth when the lesion is small enough to
allow a conservative cavity preparation
Class II lesions on mesial proximal surfaces of molars.
Class III lesions in maxillary and mandibular anterior teeth.
Class V gingival lesions.
.
INDICATIONS OF DFG

18. 2. Erosions
3. Hypoplasias
4. Teeth with no enamel crazing and microcracks.
5. Lesions in which enamel margins can be located
on sound tooth structure.
6. Lesions in vital teeth

19. OTHER USES
For restoring access opening for endodontic therapy.
Faulty margin restoration can readily be accomplished with
direct gold instead of amalgam.

20. CONTRAINDICATIONS
In handicapped, elderly or very young patient unable
to sit for longer appointment.
Physiologically unsound patient.
Teeth with large pulp chamber.
Periodontally weakened tooth.
Large carious lesion.
Chalky or melted enamel could contraindicate the use
of gold.
Poor patients.
High caries index.
Hypoplastic areas.

21. Advantages of DFG
Long lasting restoration.
Do not tarnish or corrode in the oral cavity.
Insoluble and has coefficient of thermal expansion
close to that of tooth.
Atrauamatic
No tooth discoloration
Direct gold adapts well to the cavity wall in addition no
cementing medium is necessary for retention of
restoration.

22. Ductility.
Easy to polish.
High wear resistance.
Low tendency of molecular.

23. Disadvantage
Unesthetic.
Expensive.
Patient discomfort.
Limited to small cavities.
Manipulation is difficult
Technique sensitive.
High condensation force may injure the tooth and
supporting tissues.

24. Degassing -Remove the surface impurities (ammonia gas,
wax ,other gas)
Annealing: Remove the surface impurities with internal
stress relief, restores ductility and malleability
Annealing temperature ranges from 650° to 700°c,
depending on selected method and heating time
Produce an atomically clean surface result in metallic
bonding.
REMOVAL OF SURFACE IMPURITIES /
HEAT TREATMENT / DEGASSING

25. 2. Heat treatment of gold
Gold is kept in closed container when not in use and should
not be exposed to contamination.
All 3 types of gold must receive heat treatment just prior to
condensation. This is done to degas the surface of gold and
render it cohesive.
Some of the gases may be driven off by heat while other are
irreversibly attached.
Reversible gases (oxygen and ammonia) can be readily
removed by heat in the range of 900°F to 1300°F.

26. 1. OPEN ALCHOHOL FLAME
METHOD
Also called as piece method
Heating unit used is open flame
Absolute or 90% ethyl / methyl alcohol without any additives
was used to produce a clean blue flame
Gold foil is held with a instrument and heated over a clean blue
flame of absolute alcohol.
Gold is passed over the blue flame ( reducing zone/middle zone)
for 3-5 sec
Temperature of the flame is 1300ºF and heating is done until
gold becomes dull red

27. 2.BULK METHOD
MICA TRAY OVER A FLAME METHOD:
A sheet of mica can be used over any type of flame and is used
somewhat as a heating element.
Divide the surface of the mica into several areas to indicate
the time the pieces of gold were put on the mica
Maximally five minutes are allowed for any piece of gold to be
heated on mica
Degassing of several gold pellets at
the same time is possible

28. 3. ELECTRIC ANNEALING
Electric annealing is maintained at
temperature 343 degree C (640 F)-
371degree C (700 F)
Used for powdered gold to burn away wax.
This is the most controlled and standardized
way of decontaminating gold materials.
An electric heater controls the time and the
temperature.
Maximally, five minutes are allowed for any
piece to be kept in the electric
decontaminator.

29. COMPACTIONS OF DFG
“Condensation is a procedure used to condense and harden
gold inside the cavity preparation”.
Objectives:
Gold is compacted by wedging the initial pieces
between dentinal walls.
Weld gold pieces together to ensure complete
cohesiveness of their space lattice.
Voids should be avoided from critical areas the
margins and the surface to prevent microleakage.
Bridging

30. Stepping procedure for compaction
of gold should be carried out.
Always start at point angle on one
side and proceed to other side. (tie
formation)

31. STEPS OF DIRECT FILLING GOLD
RESTORATION
1.Building of restoration
2.Paving of restoration
3.Compaction of restoration
4.Finishing of restoration:
– Burnishing
– Contouring
– Polishing
– Final burnishing

32. 1. Building of Restoration
Gold is placed in the preparation in the form of
three-step build up.
These are: Tie Formation
In this, two opposite starting points are filled with
gold so as to form a tie which acts as a foundation
for gold restoration.
Wall Banking
In this, each wall is built from its floor or axial wall
to cavosurface margin. It should be performed in
other walls also simultaneously.

33. Formation of Shoulder
This is made by joining two opposite walls
with the help of direct filling gold.

34. 2. Paving of Restoration
Every part of the cavosurface margin should be
covered with excess gold so as to overfill the
preparation.
3. Condensation
it can be either from one periphery of the increment
to other or preferable from center of the increment
to periphery (reduces voids , air entrapment)

35. Hand instrument condensation
Electronic condensation
Pneumatic condensation
TYPES OF CONDENSATION

36. GOLD CONDENSORS
DFG condensor have faces that are serrated
with pyramidal shape configuration. This system
has 3 functions:
Increase the surface area of
condenser face.
Act as surgger, thus creating lateral
forces which will help in fulfilling the
objectives of condensation.
Establish some triangular indentation
in the condensed piece of gold, so
that the succeeding increment of
gold may be interlocked and
immobilized in these indentations.

37. Round condensor
Baynet condenser
Used in initial stage of restoration.
Parallelogram and hatchet condenser
Parallelogram condensor is
perpendicular while hatchet is parallel to
shank
Used for preliminary condensation to
create the bulk of the restoration.
Foot condensers
Used mainly for cavosurface
condensation, surface hardening of
restoration as well as bulk build up.
Parallelogram condensor
Hatchet condensor
Foot condensor

38. PRINCIPLES OF CONDENSATION
Exert 15lb/sq inch of force on the
condenser nib less force is needed
for small condenser nibs than for
larger ones.
Force of condensation must be 45°
to cavity walls and floors
Force of condensation must be
directed at 90° to previously
condensed gold.

39. Two main processes which control the quality of final
direct gold restorations are welding and wedging.
Welding: process of forming atomic bonds between
pellets, layers of gold as a result of compaction
Wedging: process of pressurized adaptation of gold form
within the space between tooth structure walls or corners
minimizing voids between margin of tooth and surface of
gold.
Objectives of condensation of direct filling gold

42. Finishing of Restoration
Burnishing
First step in finishing of gold restoration is burnishing.
Specially designed Spratley burnisher is moved with pressure over restoration
to close the voids. This also enhances surface hardness of the restoration.
Contouring
Since there is excess of restoration built up to allow normal contour, this
excess restoration is removed with very sharp knives, files and abrasive stones.
Marginal excess can be removed using gold foil carver

43. Polishing
Fine garnet and cuttle disks are moved from gold towards
tooth surface for final finishing.
For polishing, silica, pumice or metallic oxide compounds
can be used. For final polish, a satin finish is preferable to a
high gloss.
Final Burnishing
Final burnishing is done to make the surface of the
restoration shiny smooth free of voids.

44. Need for base
3mm or more of remaining dentin thickness – no base
2mm or more of remaining dentin thickness – varnish on
walls and floors, without cavosurface margins
Between 1-2mm of remaining dentin thickness – sub base
of calcium hydroxide or unmodified zinc oxide eugenol
and over this varnish is applied. and zinc phosphate
cement or zinc poly carboxylate base is used .
Less than 1mm of remaining dentin thickness – direct
filling gold contraindicated