1. DIRECT FILLING GOLD

2. Direct Filling Gold
Gold was one of the earliest materials available for
restoration of teeth. “Direct golds” are those gold restorative
materials that are manufactured for directly compacting them
into prepared cavities. This noble metal is a superior
restorative material for small defects and lesions in teeth.
Direct gold restorations are highly durable if proper case
selection, cavity preparation and careful manipulation of the
material are done. Direct gold restorations exhibit excellent
marginal integrity and biocompatibility in the oral environment.

3. TYPES OF DIRECT FILLING GOLDS
There are several forms of direct gold available for restorative
purposes. All of there are cohesive and are 99.9% pure. Direct filling golds may
be categorized as follows.
I. Gold foil
A. Sheets
B. Pallets (hand rolled and preformed)
C. Cylinders.
D, Corrugated foil.
E. Platinized foil.
F. Laminated foil.
II. Electrolytic precipitated gold
A. Mat gold.
B. Mat foil.
C. Gold calcium alloy.
III. Powdered gold
A. Goldent.

4. PROPERTIES OF DIRECT FILLING GOLD
1.Pure gold is soft, malleable and ductile and does not oxidize under normal atmospheric
conditions.
2. It has a rich yellow colour and a strong metallic luster.
3. Gold fuses at 1063 C and boils at 2200 C
4. Density of pure gold is 19.0-19.3g / cm3 but this is reduced by voids incorporated during
restoration to 14-15g / cm3.
5. The Brinnell hardness number for gold is 25. This makes it very soft. However during
compaction the hardness increases to 58-82 making it a strong material.
6. The coefficient of thermal expansion of gold is 14.4 x 16-6/ C which is close to that of
tooth structure (11.4x10-6/ C).
7. Gold exhibits high thermal conductivity.
8. Gold is the noblest of all metals. It does not undergo tarnish and corrosion in the oral
environment.
9. Even small mounts of impurities can affect the mechanical properties of gold. Very small
amounts of lead, bismuth or mercury advesely affect the properties of gold. However
minute amounts of calcium, palladium and platinum can improve the properties of gold.
10 The most important property of gold which has enabled its use as a direct filling material
is its ability to be “cold welded” at room temperature. When two clean pieces of gold are
pressed firmly together under sufficient force at mouth temperature they got welded
together.
11.Gold exhibits excellent marginal integrity and biocompatibility with the oral tissues.

5. Cohesive gold
Direct gold materials that are coated with a layer of ammonia gas which is
removed just before insertion of the gold into the cavity preparation.
Non-cohesive gold
Pure gold which is contaminated with phosphorous or sulfurous gases or
other deleterious oxides. This is not cohesive.

6. ADVANTAGES OF DIRECT GOLD
1. When properly placed, direct gold is the most durable restorative material
available.
2. As pure gold is a noble metal, it does not undergo tarnish or corrosion in the
oral cavity.
3. Direct gold restorations are insoluble in the oral fluids and exhibit thermal
expansion similar to that of dentin.
4. When proper case selection is done and the cavity preparation is kept ideal, it is
atraumatic to the dental pulp and supporting structures.
5. Direct gold exhibits good adaptation to the cavity walls. Being ductile it can be
burnished against the cavity margins to create excellent marginal integrity.
6. The surface of direct gold can be polished well and the smoothness will last
indefinitely. Thus plaque accumulation is negligible over direct gold filling.
7. The density and hardness of compacted gold provide adequate compressive
strength.

7. DISADVANTAGES OF DIRECT GOLD
1. The yellow colour of pure gold is not esthetically acceptable to
most patients.
2. The manipulation of gold is very exacting and difficult to master.
3. Placement of direct gold is time consuming requiring a lot of
attention to detail.
4. Direct gold is a very expensive material.
5. Thermal conductivity of gold is high. So pulp protection is
necessary under gold restorations.

8. INDICATIONS FOR DIRECT FILLING GOLD RESTORATIONS.
1. Class I cavity: Direct gold is indicated for small carious lesions in pits and
fissures of posterior teeth and lingual surfaces of anterior teeth.
2. Class II cavity: Direct gold is indicated for minimal proximal caries in
posterior teeth especially premolars when marginal ridges are not subjected
to heavy occlusal stresses.
3. Class III cavity: Direct gold can be used for small carious defects in
anterior teeth when the defect is only on the proximal surface and esthetics
will not be affectd.
4. Class V cavity: For minimal caries in the cervical 1/3rd of teeth direct gold
can be used. It is also indicated for small abrasion, erosion or abfraction
defects on the facial surfaces of teeth.
5. Class VI cavity: For restorations involving incisal edges or cusp tips, direct
gold may be used, provided there is no heavy occlusal stress.
6. Defective crown margins: Defective crown margins of cast gold crowns
may be repaired with direct gold. Whenever access opening are done
through existing cast gold crowns, they may be sealed with direct gold after
the endodontic therapy.

9. CONTRAINDICATIONS FOR DIRECT FILLING GOLD RESTORATIONS
1. Young patients: In young patients because of the presence of large
pulp chambers direct gold is contraindicated as the malleting forces of
direct gold may not be tolerated by the pulp.
2. Poor periodontal status: In periodontally weakened teeth, direct gold
is not employed because of questionable prognosis.
3. Heavy occlusal stresses: For moderate to large carious defects
direct gold is not used as it canot withstand heavy occlusal loading.
4. Economics: Direct gold is not indicated when cost is the limited
factor.
5. Handicapped patients: Long appointments are necessary for direct
gold. Hence, it is contraindicated in handicapped patients.
6. Esthetics: When esthetics is the main concern for the patient direct
gold is not recommended.
7. Access and isolation difficulties: Direct gold is contraindicated in
inaccessible regions and areas where isolation cannot be adequately

10. GENERAL PRINCIPLES OF CAVITY PREPARATION FOR DIRECT
GOLD RESTORATIONS
The principles of cavity preparation for direct gold restorations are very
exacting and require careful attention
The outline form should include all structural structure. The outline should be
smooth and designed to be esthetically pleasing.
Resistance form is achieved by creating flat pulpal floors perpendicular to
occlusal forces. The walls must be smooth and flat. Enamel walls must be supported
by sound dentin. The cavity width must be minimal while providing adequate
convenience form.
Retention form is achieved by parallel or slight occlusal convergence of the
facial and lingual walls. The depth of the cavity should be 0.5 mm into dentin. The
presence of sharp internal line angles resist the movement of the restoration.
Convenience form for direct gold cavity preparations require suitable access and a
dry field. The width of the cavity preparation should be minimal. Separators may be
used to provide convenient access for Class III cavity preparations. Sharp internal
line and point angles in dentin serve as convenient “starting” points for compacting of
direct gold.
Other principles like removing remaining caries, finishing the cavity walls,
debridement and pulp protection are similar to other cavity preparations.

11. CLASS III CAVITY PREPARATION FOR DIRECT GOLD RESTORATIONS
Several designs have been advocated for Call III cavity
preparations for direct gold.
These include the Ferrier design, Loma Linda design, Woodbury
design and Ingraham design. Of these, the Ferrier design is
most popular because of the following reasons:
1. It conserves tooth structure.
2. It provides good access for compaction of gold.
3. The final restoration would be esthetically pleasing.

12. GENERAL STEPS FOR DIRECT GOLD RESTORATIONS
1) Build- up of the restoration
a) Tie Formation: This involves connecting two opposing point angles
or starting points filled with gold with a transverse bar of gold. This
“tie” forms the foundation for any restoration in direct gold.
b). Banking of the walls: This consists of covering each wall from its floor
or axial wall to the cavosurface margin with the direct gold material.
Banking should be done simultaneously on the surrounding walls of the
preparation.
c) Shoulder formation: This consists of connecting two opposing walls
with the direct gold material to completely fill up the restoration.

13. 2. “Paying’ of the restoration
To overfill the preparation every area of the cavofurface margin should be
individually covered with excess cohesive gold foil. This is condensed with a
rectangular “foot” condenser.
3. Surface hardening of the restoration
The rectangular condenser is used with the highest possible condensation
pressure in all directions on the surface of the restoration to strain harden the
surface gold.
4. Burnishing
This is done with a suitable burnisher moving from the gold to the tooth surface.
This enhances the surface hardening and also produces good marginal
adaptation of the gold.
5. Margination
This step uses sharp gold knives to remove excess gold from the surface to the
tooth.

14. 6. Burnishing
It is important to burnish the surface of the gold restoration after margination so as
to eliminate marginal discrepancies and to strain haredn the surface.
7. Contouring
This step uses knives, files or finishing burs to create the proper occlusal anatomy.
Burnishing.
8. Finishing and polishing
Direct gold restorations require very little finishing if the previous steps are
property done. Finishing can be done using tin oxide powder on soft bristle
brushes or rubber cups.
9. Final burnishing
This is done after polishing to make the surface of the restoration smooth and free
from voids.