direct filling gold... material aspect, types, condensation, cavity design, modifications. detaied seminar for post gradutes.... any doubts or suggestions contact dr.mb@hotmail.com
CEHPALOSPORINS.pptx By Harshvardhan Dev Bhoomi Uttarakhand University
Direct Filling Gold
1. DIRECT FILLING GOLD
Dr. Madhu Billa
I MDS
DEPT OF CONSERVATIVE DENTISTRY AND ENDODONTICS
SIBAR INSTITUTE OF DENTAL SCIENCES
2. CONTENTS
INTRODUCTION
HISTORY
PROPERTIES
INDICATIONS
CONTRAINDICATIONS
BIOLOGICAL
CONSIDERATIONS
DIFFERENT FORMS OF GOLD
Dr.MadhuBilla
3. METHOD OF DEGASSING
CONDENSATION
TYPES OF CONDENSATION
STEPS FOR PLACEMENT OF DFG
FINISHING
CAVITY PREPARATION
CONCLUSION
Dr.MadhuBilla
4. INTRODUCTION
Among the available restorative materials, direct filling
gold is the oldest filling material that is still used in restorative
dentistry.
The vision to utilize the noble metals for the replacement of
lost tooth structure stemmed from perfect harmony of its
biological and mechanical properties.
Dr.MadhuBilla
5. While most of metals can be welded and alloyed at a
temperature above the room temperature, the pure gold can
be cold welded and made to adhere to each other at room
temperature.
For a pt gold foil means no second appointment, no second
administration of L.A and no second application of rubber
dam. Lastly as quoted by B.Smith it may serve the tooth for
a lifetime.
.
SMITH B J OF SOTH CALIFORNIA STATE DENTAL ASSC. 1959
Dr.MadhuBilla
6. 1483- Giovanni d arcoll first recommended gold leaf as
restorative material
1712-1786- Frederic used for pulp capping
1795 - Robert woffendale introduced gold foil for restoration
purpose in America
1803 –Edword Hudson used goldfoil to fill root canal
1838- Dr .E. Meritt of pittsburg introduced hand mallet for
compaction.
HISTORY
Dr.MadhuBilla
7. In 1840 Jackson first introduced sponge (Crystal
or crystalline) gold which was easier to condense.
In mid 1850’s Robert Arthur of Baltimore introduced the
technique of heating pieces of sponge gold over a “Spirit
lamp” to make them cohesive
1892- Power And Bonwill developed the pneumatic hammer
1896- Bryan referred to mat gold
Dr.MadhuBilla
8. 1964- Goldent powdered gold was introduced
1969 – R.V.Willams and C.Ingersoil introduced
Electralloy
1980- E-Z gold were introduced by Baum
1989-new granular type of gold stopgold was
introduced by Dhiek and Regelstein
Dr.MadhuBilla
9. PROPERTIES
Gold (Au)
Atomic number – 79
Atomic weight – 196.966amu
Melting point – 1064.43ºc
Boiling point – 2807ºc
Brinell’s hardness number – 25
Malleability - It exceeds all other metals in this respect. It
may be reduced by beating to sheets of 1/250,000 of an inch
in thickness.
Ductility-It is most ductile of all metals
Dr.MadhuBilla
10. INDICATIONS
Incipient carious lesion
Occlusal, buccal, lingual pit
Class II lesions on premolars and molars
Class III in mandibular anteriors
Class V in bicuspids, cuspids (where esthetics permit)
Erosion areas
Dr.MadhuBilla
11. Atypical lesions
Proximal lesions on teeth adjacent to crown preparations
Class VI lesions
Retrograde root canal filling material
Dr.MadhuBilla
12. CONTRAINDICATIONS
Very young and old patient
Teeth with large pulp chamber
Periodontal weakened teeth
Economy is limited factor
Handicapped patient
Root canal treated teeth
Dr.MadhuBilla
13. Under developed root
Caries prone mouth
Hypersensitive cavities
Extensive cavities with weakened walls
Lack of skill of operator
Dr.MadhuBilla
14. ADVANTAGES
Insoluble in oral fluids
More resistant to tarnish and corrosion
Perfect adaptation to cavity wall because of ductility
More edge strength
Low tendency to molecular change (free from shrinkage or
expansion)
Maintain high polish
Advantages of direct gold filling by L.Clarke
Operative dentistry 1985 10-22Dr.MadhuBilla
15. No intra cement substance needed
Thermal expansion similar to dentin
Oral tissue accepts readily
Causes no tooth discoloration
Advantages of direct gold filling by L.Clarke
Operative dentistry 1985 10-22Dr.MadhuBilla
16. DISADVANTAGES
Inharmonious color
Thermal conductivity can be a problem in a newly restored
teeth.
Can lead to sensitivity to hot and cold
Advantages of direct gold filling by L.Clarke
Operative dentistry 1985 10-22Dr.MadhuBilla
17. Manipulation of gold is difficult to master. It requires skill
and practice
Non-cohesive gold may be used on account of its
rapidity of manipulation in simple cavities with four
strong walls, located on surfaces not subject to wear.
It is not indicated on surfaces subjected to stress of
mastication or for contour work
Advantages of direct gold filling by L.Clarke
Operative dentistry 1985 10-22Dr.MadhuBilla
18. Energy of condensation which is not absorbed by the restorative
material, may dissipate to the pulp dentin organ
Thermal energy in the pellet, exceeding that needed for
decontamination – causes pulpal irritation
Frictional heat of finishing and polishing
Galvanic current between gold and other metallic restorations
Ultrasonic energy from high condensation frequency can harm pulp
BIOLOGICAL CONSIDERATIONS
Dr.MadhuBilla
19. 3mm or more of remaining dentin thickness – no base
2mm or more of remaining dentin thickness – varnish on walls
and floors, without cavo surface 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
Need for base
Dr.MadhuBilla
20. In a study done by Draheim et al., On the ability of
cavity bases to withstand condensation of direct gold
concluded that ZOE and calcium hydroxide
containing bases have silmilar abilities to withstand
condensations of direct filling gold
Authors concluded that ZoE and calcium hydroxide cavity
bases tested had adequate strength to resist the forces of
condensation of electraloy
The ability of cavity bases to withstand condensation of direct gold
Quintessence International 11/1985
Dr.MadhuBilla
23. Gold foil:
Gold foil sheets are manufactured by a process called gold
beating or rolling
All light weight sheets are formed by beating and heavy
weight sheets are formed by rolling
In beating process, first heavier mallets are used followed by
lighter ones as gold gets thinner.
Dr.MadhuBilla
24. For rolling, it is passed through rolling mills until desired
thickness is got.
It comes in a book of 1/10 or 1/20 ounces. One book has
12 sheets with a common dimension of 4 x 4
No. 4 gold foil weighs 4 grains (0.259gm) and is 0.51µm
thick
No. 3 gold foil weighs 3 grains (0.194gm) and is about
0.38µm thick
Dr.MadhuBilla
25. During manufacture, pure gold ingots are subjected to cold
working, thereby creating sheets out of blocks.
As the gold is subjected to strain hardening during this process,
for further cold working towards the formation of these leaves or
sheets, the material should be subjected to proper annealing
This alternate process of cold working and annealing - cold
working continues until the desired thickness of the gold sheet is
arrived at.
Dr.MadhuBilla
26. Extra liable gold foil:
It was made to produce a more cohesive gold
Extra labile gold has improved tendency to cohere
Formed by wrapping a loosely formed, regular gold
rope with an extra sheet of gold foil
Dr.MadhuBilla
27. Gold foil pellets:
May vary from ½ - 1/128th of a portion of No. 4 gold foil
After removing the gold foil along with the tissue paper from
the book. Foil is held on paper and is cut to the size needed.
Paper supports the thin gold foil and prevents it from tearing
and wrinkling during manipulation
Dr.MadhuBilla
28. • Sizes used are from 1/10 onwards. Larger sizes of 1/2,
1/4, 1/8 are used for making cylinders. The desired piece is
then grasped by index, thumb and middle finger of left
hand. Ends are touched with tweezers towards the center
and are rolled into loose balls
• Pellets are degassed and stored in separate compartment
Dr.MadhuBilla
30. Gold cylinder
Can be hand rolled or commercially rolled
Made by rolling the cut segment of No. 4 foil into 1/2, 1/4, 1/8
widths
Dr.MadhuBilla
31. Corrugated gold / carbonized gold
foil
This was first observed by a dental dealer in the great
Chicago fire of 1871.
Corrugated gold foil is manufactured by placing a thin
leaf of paper between two sheets of gold foil, after which the
whole container accommodating paper leaves and gold foil is
ignited.
As the paper leaves are burned out, they shrivel, and
thereby impart a corrugated shape to the gold foil
It has been proven that corrugated gold foils are more cohesive
than the plain ones.
Dr.MadhuBilla
32. Platinised gold foil:
It’s a sandwich of gold and platinum with platinum content being 15%
One sheet of platinum foil is sandwiched between two sheets of gold
foil and is then hammered to the thickness of NO. 4 gold foil
Layers of gold and platinum are rolled over together so that there
occurs fusion of the two even before the beating procedure begins
Platinum increases the hardness and wear resistance of the restoration.
So this form can be used in stress concentration areas like incisal edges
and cusp tips.
Dr.MadhuBilla
33. • When a cube of gold ingot is cold worked in order to
formulate a sheet, the cubical crystals of gold will he
stretched and elongated in a specific direction.
• If the gold foil of that cube is viewed under a microscope.
It appears fibrous, with the fibers parallel to each other in a
specific pattern.
• Mechanically speaking, this type of gold foil material will
have directional properties, i.e., It will be resistant to
stresses in one direction better than the other.
LAMINATED GOLD FOIL
Dr.MadhuBilla
34. The idea of laminated gold foil is to combine two or three
leaves of gold, each from different ingots which have been cold
worked in different directions.
Although each leaf will be directional in its properties, when
combined together, they can be resistant in different directions.
Therefore, laminated gold foil is definitely much stronger and
much more resistant to stresses than the other forms of direct
gold materials.
Dr.MadhuBilla
35. Cohesive gold:
Is that form of gold which is essentially free of any surface
contaminants and can be placed directly into the cavity
Gold can attract gases to its surface, and any adsorbed gas
film can prevent intimate atomic contact required for cold
welding.
So manufacturer supply the foil free of surface contaminants
and therefore inherently cohesive this type is reffered to as
cohesive foil.
Dr.MadhuBilla
36. Semi cohesive gold:
Some gold sheets have adsorbed protective gas film such as
ammonia.
This minimize the adsorption of other less volatile substances
and prevent premature cohesion of sheets.
The volatile film is readily removed by heating to restore the
cohesive character of the foil.
This type is reffered to as semi cohesive gold
Dr.MadhuBilla
37. Non cohesive gold:
Non volatile contaminants like iron, sulphur, phosphorous are
permanently deposited on the surface.
This cannot be driven away by heat and so gold loses it cohesive
property.
Non cohesive forms are used as starting material, since they can
be worked more easily than cohesive forms.
But they don’t have good strength and hardness.
Dr.MadhuBilla
39. MAT GOLD
It is an electrolytically precipitated crystalline form that is
sandwiched between sheets of gold foil and formed into strips
These strips are cut into desired sizes
Preferred for its ease in building up the internal bulk of the
restoration as it can be more easily compacted and adapted to the
retentive portions of the prepared cavity
Dr.MadhuBilla
40. As it is loosely packed it is friable and contain numerous void
spaces between the particles
So it is recommended for the external surface of the restoration
Using this two material technique the mat is covered with
veneer of foil
Loosely packed crystalline form with large surface area of the
mat powder it does not permit easy welding into a solid mass
as does gold foil
Dr.MadhuBilla
41. Advantages:
Rapid filling,
Filling Internal bulk (cavity walls ,and retentive
portions) It is used to form the core of the restoration
Average size is 10 to 20µm
Dr.MadhuBilla
42. Disadvantages:
Difficult to handle, Voids ,surface pitting, and ditching, rough
finishing,
More condensation pressure required, crumbles during
manipulation
Does not permit welding into homogenous mass
Dr.MadhuBilla
43. MAT FOIL
This is a sandwich of Mat Gold placed in sheets of No 3 / 4 gold foil.
The sandwich is sintered by heating to just below the melting point of
gold and cut into strips of different widths
The gold foil cover holds the crystalline gold together while it is being
condensed.
Mat Gold Foil By Koser And Ingraham Operative Dentistry Vol 52 1956Dr.MadhuBilla
44. • Mat gold foil differs from the so-called cohesive type foils. It is a
fine, electrolytic, crystalline deposit made adhesive by the nature
of its finely divided crystalline structure and by the extremely
pure state of the metal itself.
• Its mechanical strength is the result of a special molding and
heat treatment process.
• This property renders it easier to manipulate.
• Because mat gold foil is highly adhesive and cohesive, and
because it is more readily adaptable than other types of foil, it is
ideally suited for building up the internal bulk of Class V, Class I
and the occlusal portion of Class II restorations.Dr.MadhuBilla
45. ALLOYED ELECTROLYTIC PRECIPITATE
This is an alloy of electrolytic gold and calcium
The calcium content is usually
0.1- 0.5 % by weight
Its purpose is to produce stronger restorations by
dispersion hardening.
For convenience, the product is sandwiched between
two layers of gold foil
Dr.MadhuBilla
46. ELECTROALLOY R.V.
This is a mat gold manufactured by Williams Gold
Refining Company, New York.
R.V stands for R.V. Williams who developed this
Dr.MadhuBilla
47. POWDERED GOLD
It is a blend of atomized and precipitated powder embedded in
a wax-like organic matrix.
This form was introduced in 1962 by Baum and Lund.
The atomised and chemically precipitated powders are first
mixed with a soft wax to form pellets
These wax gold pellets are wrapped with foil
The resulting pellets are cylindrical and are available in
different diameters and length
Dr.MadhuBilla
48. Commercially available pellets of powdered gold wrapped in a
gold foil are known as “ goldent”
Introduced in 1960’s
The individual particles or granules are of 15µm are gathered
into mass of irregular shape ranging in size from 1-3mm
precondensed lightly to facilitate handling
These masses are encased in an envelope of foil to make it
easier to convey them to the cavity
Dr.MadhuBilla
49. E- Z Gold
It is similar to Goldent but with improved working properties marketed by
Williams Gold Refining Company, New York, introduced in the late 1980s
It is a mixture of pure gold powder and wax (less than 0.01% organic wax),
wrapped in gold foil
Its manipulative characteristics are similar to stiff amalgam yet more
cohesive than gold foil hence the name e-z gold
EZ-Gold The New Goldent By Alperstein , Yearwood
Jod 1996,21, 36-41Dr.MadhuBilla
50. metallurgically similar to gold foil and powdered gold (Goldent)
in that, when properly and thoroughly compacted, it has
comparable properties: inertness (biocompatibility) and
permanence.
It is recommended for use in small class-I and class-V LESIONS
It is less time consuming and more predictable
Greater expected longevity and more favourable tissue response
Dr.MadhuBilla
51. Stopfgold: a new direct filling gold
A new direct gold material that is considerably different from other
direct golds has been available since 1989.
The advantages are that the final restoration exhibits greater density
than other forms of granular gold and has a 50% increase in shear
strength when compared to gold foil.
Clinical experience with the use of this new restorative material has
been encouraging.
Stopfgold: a new direct filling gold. Lambert RL;
[Oper Dent] 1994 Jan-Feb; Vol. 19 (1), p. 16-9.Dr.MadhuBilla
52. REMOVAL OF SURFACE IMPURITIES /ANNEALING
HEAT TREATMENT/DEGASSING
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,depended on
selected method and heating time
Produce an atomically clean surface result in metallic bonding
Dr.MadhuBilla
53. 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 alchohol
METHOD OF DEGASSING
Dr.MadhuBilla
54. 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
Advantages:
Less contamination
Less wastage of the material
Desired size of piece can be selected
Disadvantages:
Time consuming.
Dr.MadhuBilla
55. 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
Dr.MadhuBilla
56. ELECTRIC ANNEALING
This is the most controlled and standardized way of decontaminating
gold materials.
With this instrument, the heated compartment area is made of
aluminum. An electric heater controls the time and the temperature.
The surface of the heater is divided into small compartments. each
accommodating a piece of direct gold.
This eliminates the possibility of cohesion of the pieces before they are
inserted into the cavity preparation.
Maximally, five minutes are allowed for any piece to be kept in the
electric decontaminator.
Dr.MadhuBilla
57. Electric annealing is maintained at temperature
343degree C (640 F)- 371degree C (700 F)
Used for powdered gold to burn away wax
Disadvantage:
stick together if the tray is moved, size selection
among the piece of degassed gold is limited ,more
chance of contamination.
Dr.MadhuBilla
58. Heating time depend on size and configuration of gold
segment (powdered gold-15-20 sec, gold foil pellet,
electrolytic gold -1-2 sec)
Avoid over heating and under heating
Over heating: recrystallization, grain growth Incorporation
of impurities ,more stiffness, less ductile, difficult to
condense, non cohesive, particles adhere to each other,
excessive sintering
Under heating: partial cohesiveness, peeling away of
adjacent segment or layer, pitting, porosity in final
restoration
Dr.MadhuBilla
59. Precautions to be taken using
flame:
Lamp should not run out of fuel during procedure
There should be no surface contaminants on lamp and wick
wick should be properly trimmed and rounded to produce a tear
drop flame
sulphur in matches could adhere to the wick and contaminate
the gold. So ignite with other end of the match
Dr.MadhuBilla
60. STORAGE OF GOLD FOIL
Gold is packed into the preparation under pressure so that under
welding minimal porosity occurs
Protecting Gold Foil from contamination by gases with a thin film
of alkaline salts.
This protective film, usually of ammonia, prevents deleterious
gases from condensing directly on the Foil.
Instead, these gases combine with ammonia, to form other salts,
and they are neutralized by it when it is present in excess. They are
then driven off by annealing.Dr.MadhuBilla
61. Condensation /compaction
Objectives:
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.
Dr.MadhuBilla
62. PRINCIPLES OF CONDENSATION
1. Force of condensation must be 45° to the cavity walls and
floors,
Bisect the line angle and trisect the point angle (result in
maximum adaptation ,minimum irritation to vital pulp and dentin
Dr.MadhuBilla
63. 2.forces of condensation must be directed at 90degrees to
previously condensed gold
3. always start at point angle on one side and proceed to
other side. (tie formation)
Ensure condenser has covered entire piece of gold
Condenser has to over lap at least ½ of the previously
condensed areaDr.MadhuBilla
64. 4. use minimum thickness of pellet as possible
5 Energy of condensation :
Less energy is used inside cavity preparation
Gradually increase the energy of condensation as build up proceeds
to surface
Maximum energy is used at surface of restoration
Dr.MadhuBilla
65. 6. Condensation can be either from one periphery of the increment
to other or preferable from center of the increment to periphery
(reduces voids , air entrapment)
Dr.MadhuBilla
66. CONDENSERS
Condensors are used to deliver forces of compaction to
DFG
These condensors have three Parts:
• Handle
• shank,
• nib (working end)
Dr.MadhuBilla
67. CONDENSER NIB:
Common feature of all Condenser are faces are serrated with
pyramidal shape configuration
Conensors based on Shapes of nib:
• Round condenser/bayonet condenser-used starting, nib face is
0.4 to 0.55mm
• Parallelogram and hatchet condenser - preliminary
condensation, create bulk in restoration, nib face is approximately
0.5x1mm
• Varney Foot condenser - has rectangular face, it measures
approximately 1x1.3mm - used for bulk built up
Dr.MadhuBilla
68. CONDENSER SHANKS
Available as :
straight ,
monoangle,
offset,
binangle
Condenser used for hand malleting have longer shank,
than condensors used in other mechanical means.
Dr.MadhuBilla
69. Force required for compaction is proportional to size of nib
of the condenser.
Force delivered by compaction is inversely proportional to
size of the nib of the condenser.
Smaller the nib face more square inch force is delivered
f = 1/d2 (d is reduced by ½, force /square inch
delivered by condensation increase by 4 times more)
Dr.MadhuBilla
70. There are several methods for the application of these
forces:
Hand pressure
Hand malleting
Automatic hand malleting
Electric malleting
Pneumatic malleting
Dr.MadhuBilla
71. METHODS OF CONDENSATION
1.Hand pressure condensation
Used as first step in 2 step condensation as Initial confinement
of material within the cavity,
Compaction method is similar to amalgam condensation except
force and duration of force is more
The condensation energy produced by this method is not always
sufficient to fulfill the objectives of the condensation however it
can be used simply to effect the initial confinement of the
material within the cavity preparation.
Dr.MadhuBilla
72. AUTOMATIC HAND CONDENSER
This is a spring loaded instrument
Blows are delivered by releasing a spiral spring
Its main advantage is it gives a series of well regulated blows
Disadvantage: blow descends before full pressure is applied
Dr.MadhuBilla
73. CONDENSATION BY HAND MALLEATING
One of the oldest, preferred by most clinicians
Requires trained assistant
Correct form of hand malleting : requires light force, bouncing
application of mallet to condenser rather then delivering heavy
blows (blow must be carefully adjusted it must not be too strong
or too heavy,), mallet must travel parallel to central axis of
Handle of condenser
Advantage: greater control of malleting force, varying force are
used, rapid change of condenser tip.
Dr.MadhuBilla
74. CONDENSATION BY MECHANICANAL
MEANS
consist of condenser with working tip and short shank
(<1 inch ) with fits into malleting hand piece (either
straight or right angled hand pies)
Advantage: frequency and intensity of blow can be
controlled
reduced fatigue
Types:
a.Pneumatic condensation-Hollen back
b. electronic condensation- Mc ShirleyDr.MadhuBilla
75. A.PNEUMATIC CONDENSATION
Developed by Dr George. M Hollen back
Consist of electric engine and air condenser, air is carried
through thin tube to hand piece
Condenser vibrates which is energized by compressed air
Number of blows -360 /min
Advantage: blow does not fall until pressure is placed on
condenser point and continues until released
Dr.MadhuBilla
76. B. ELECTRONIC CONDENSATION:
Developed by Mc Shirley
Most efficient and controlled way of condensation
Vibrating condenser head - intensity and amplitude is 20 to
15lbs and frequency of blow is 360- 3600 cycles/min
Dr.MadhuBilla
77. General steps for insertion of DFG into
tooth preparation
A. Three steps building up for the restoration
Tie formation – is connecting two opposite point angles with a
transverse bar of gold. This ‘tie’ forms the foundation of any direct
gold
Banking of walls – covering each wall from its floor ,Or axial wall
to cavosurface margin with direct gold. The wall is banked without
obstructing tie formation or banking of other walls. It is done
simultaneously on other walls too.
Shoulder formation – to complete a build up, two opposing walls
are connected with direct gold
Dr.MadhuBilla
78. B. Paving of the restoration
Every area of cavosurface margin is individually covered with
excess gold foil .
Condensation from center to periphery is better than periphery
to center, since it decrease the trapped air bubbles
C. Surface hardening of restoration
Utilizes the high condensation energy in the restorative procedure,
so as to strain harden the surface gold and fulfill the objectives of
restoration
Dr.MadhuBilla
79. FINISHING
Proper finishing might more aptly be described as additional
condensation.
Despite the most careful precautions, a condensed mass of gold
will be having minute air pockets incorporated into it. When
polishing these voids spaces are exposed leaving tiny pits that
may not be readily discernible until after the final finish.
Finishing consist of following three operations
1. removing of excess gold
2.elimanating pits on the surface
3.polishing the surface.
Dr.MadhuBilla
80. 1.Removal of gold – with the use of various rotary
instruments such as disks and finishing burs
2.Elimanating pits on the surface- with the use of burnishing
hand instruments including gold files, discoid carvers and
gold knives, beaver tail burnisher
3.Polishing the surface- with the use of fine garnet and cuttle
disks, abrasive strips, pumice and powdered chalk.
Dr.MadhuBilla
83. SIMPLE CLASS-I DESIGN
I. General shape
The outline is similar to class I cavity preparations for amalgam,
but with three modifications:
A. Instead of rounded corners in the triangular and linear fossa areas,
these preps have angular corners.
B. The extensions in the facial and lingual grooves in molars
will end in a spear-like form, i.e., A pointed termination, rather than
rounded.
C. The sweeping curves of the outline form of the cavity
preparation compared to those for amalgam are less pronounced. In
other words, the whole outline will look more angular than in
preparation for amalgam.
Dr.MadhuBilla
84. 2. Location of margins
The facial and lingual margins of these preparations will be
on the inclined planes of the corresponding cusps or marginal
ridges, so that the width of the cavity will not exceed 1/5th the
intercuspal distance.
The mesial and distal margins will also be conservatively located on the
inclined planes of the corresponding ridge, very close to the adjacent pits.
Dr.MadhuBilla
85. Internal anatomy:
The mesiodistal and facio lingual cross section of
cavity preparations are very similar to those
found in amalgam class-I with two exceptions
• The line and point angles are definite and
very angular within dentin substance
• The cavosurface margins should be
beveled with a partial enamel bevel this
should be 45º to the direction of enamel
rods.
Dr.MadhuBilla
86. Complex class-I cavity preparations:
These are class-I cavity preparations with facial and/or lingual extensions.
They will have the same general shape, occlusally, as the simple design.
The facial and/or lingual extensions will be parallelogram shape.
The location of margins is exactly as in the preparation for amalgam,
except the mesio distal width of the facial and lingual portions of the cavity
preparation should be very limited (1 mm, if possible). The internal
anatomy of these cavities will also be similar to the simple design in their
occlusal part.
However, it is necessary to have starting points At the mesial and distal
axio gingival corners of the facial and lingual extensions And again a
partial enamel bevel is mandatory
Dr.MadhuBilla
87. Pulpal floor - 0.5mm into dentin
Undercuts if desired are placed facially and lingually in
posterior teeth, and incisally and gingivally on lingual
surface of incisors.
Cavosurface bevel- 30-40 degree metal at margin for ease
of burnishing the gold
Bevel - 0.2mm in width
Dr.MadhuBilla
89. Class-II cavity preparation:
CONVENTIONAL DESIGN
General shape:
The occlusal outline is an exact replica of the simple Class I
cavity preparation in molars and premolars, The isthmus
portion will definitely have a reversé S-shaped outline
facially and lingually due to the very narrow occlusal
preparation in transition to a regular size contact area.
The proximal portion outline will be a one-sided inverted
truncated cone. On the upper teeth, truncation will be at the
expense of the lingual proximal wall, and on the lower teeth,
truncation will he at the expense of the buccal proximal wall.
In other words, the inverted truncation is at the expense of the
functional cusp side.Dr.MadhuBilla
90. Location of margins
• The occlusal portion will have its margins exactly in the same location
as the simple Clãss I on the occlusal surfaces of molars and premolars.
• However, there is no need for ‘dove tailing” in locating those margins.
The isthmus portion will have its margins located on the inclined planes
of the remaining parts of the marginal ridge and the adjacent cusps, so
that the width of the cavity will not exceed 1/5th the intercuspal
distance.
• The margins gingivally will just clear the contact area. There should not
be any effort to put the margins subgingivally.
Dr.MadhuBilla
91. Internal anatomy
A. A mesio-distal cross-section enables visualization of the proximal, pulpal. Axial,
and gingival walls and floors. They can be seen to have the same angulation as in
class II, design I for amalgam. With two exceptions:
I. All line angles, with the exception of the axio-pulpal, will be very sharp.
Ii. The cavosurface margins are bevelled at almost 45° to the plane of the enamel
walls.
B. The facio-lingual cross-section at the gingival one-third indicates that the axial
wall will be convex, following the curvature of the proximal surface.
Dr.MadhuBilla
92. THE CONSERVATIVE DESIGN:
• The general shape and location of margins are similar to that of
amalgam preparations.
Internal anatomy
• Mesio-distal cross section:
This section shows a very slanted axial wall, formed of
dentin and enamel. The enamel portion is partially beveled towards the
occlusal.
• The gingival floor is in four planes: an internal, reverse-bevel plane,
making an acute angle with the axial wall and formed completely of
dentin; a transitional plane, formed completely of dentin and slightly
flat: an outer, enamel dentinal plane following the direction of the
enamel rods and, finally, a partial bevel on enamel only, not to include
more than 1/4th of its extent.
Dr.MadhuBilla
93. b. Facio-lingual section:
The triangular areas, facially and lingually, will extend to just short
of the occlusal enamel, leaving a limited thickness of dentin to
support the occlusal enamel.
The triangular area joins the reverse bevel internally via a rounded
junction.
Dr.MadhuBilla
94. SIMPLE DESIGN
General shape:
Similar to that of amalgam except that it has a more angular junction
between the different margins
Location of margins As the whole surface is self clensible the margins
can be placed anywhere on the surface.
Internal anatomy:
a. An occluso-gingival cross-section will show that the occlusal wall
is formed of three planes, one plane in the form of dentin,
and at right angle to the axial wall; a second plane inclining
occlusal proximally, and formed of enamel and dentin; and a
third one in the enamel wall, in the form of a bevel.Dr.MadhuBilla
95. • B. In a facio-lingual cross-section the axial wall will appear to be flat to
slightly rounded. The facial and lingual walls will have the same
anatomy
If the facial and lingual margins are in the middle third of the proximal
surfaces of the corresponding walls two internal planes can be combined into
one, following the direction of the enamel rods.
Dr.MadhuBilla
96. Class V cavity preparation:
Ferrier design
Outline -trapezoidal
Gingival wall and occlusal wall are flat and
parallel to occlusal plane
Occlusal wall is longer than gingival
Mesial and distal walls makes an obtuse angle with
the gingival wall and an acute angle with the
occlusal wall
Dr.MadhuBilla
97. Mesiodistally axial wall can be curved so as to prevent
encroachment on the pulp
But excessive curvature results in preparation which is too
shallow in centre or too deep proximally.
Axial wall is 1mm deep occlusally and as it comes down
cervically, its 0.75mm
Mesioaxial and distoaxial line angles are obtuse so as to prevent
any undermined enamel and also gives resistance to movement
of gold during compaction.
Dr.MadhuBilla
98. The mesial and distal walls provide resistance for gold
compaction, but they don’t give retention.
Retention is provided by sloping of the gingival wall internally to
meet axial wall in a sharp defined acute axio gingival line angle.
Retention so is achieved by facial convergence of occlusal and
gingival walls.
Where gingival margin is on enamel, cavosurface is beveled,
when it is on cementum, its not beveled
Hoe is used for planning the restoration walls and giving sharp
internal line angles
Dr.MadhuBilla
99. According to the caries extent, different designs of
Class-V preparation can be made.
Semilunar shaped cavity
Class V with uni or bilateral mustache extension
Parallelogram in design
Class V with proximal pen handle extension
Dr.MadhuBilla
100. FERRIER DESIGN PEN HANDLE EXTENSION
UNI & BI LATERAL MOUSTACHE EXTENSION CRESENT MOON SHAPEDDr.MadhuBilla
101. CLASS-III CAVITY PREPARATION
There are three basic designs for class-III preparations:
The Ferrier design
The Loma linda design
The Ingraham design
Dr.MadhuBilla
102. THE FERRIER DESIGN
It is indicated if after removal of all the diseased and
undermined tooth structure, bulky labial, lingual,and incisal
walls remain
Furthermore it is indicated if the labial extension of the lesion
facilitates minimal extension of cavity preparation labially.
General shape:
Its outline is triangular in shape involving about 2/3rd’s to one
half of the proximal surface
LOCATION OF MARGINS:
Being a labial and lingual cavity the labial and lingual margins
should be within corresponding embrasures
Dr.MadhuBilla
103. Internal anatomy:
In labiolingual cross section it can be seen that the axial
wall is rounded but not following the convexity of
proximal surface.
In the inciso gingival cross section the incisal wall appears
as in class v cavity preparation i.e. Formed of three or four
planes
All the line angles and point angles should be sharp with
exception of junction between the line angles of the cavity
preparation proper and those of retention forms which
should have a rounded junctional relationship.
Dr.MadhuBilla
104. INSTRUMENTATION
No 33 ½ bur or suitable
Wedelstaedt chisel –used from
facial aspect to position the
gingival outline and the facial
wall.
Planning the labial wall and
incisal out line with
wedelstaedt chisel
Planing the incisal wall with
angle former Dr.MadhuBilla
105. Establishing the lingual
wall with wedelstaedt
chisel
Removal of the
linguogingival bulk with
inverted cone bur (33½)
Planing the the gingival
wall and labial wall to
establish the résistance
form using 6 ½-2 ½ -9 ½
hoe
Dr.MadhuBilla
106. Hoe is used to planning
the lingual wall and
sharpening linguogingival
line angle and
linguogingivoaxial point
angle
Axial wall is planed with
hoe to give convex surface
Dr.MadhuBilla
107. Small angle former-
complete the sharp
point angles and
acute axiogingival
angle
Bibeveled hatchet
(3-2-28)-establish
the incisal retentive
angle with chopping
motion
Dr.MadhuBilla
108. LOMA-LINDA DESIGN:
This design is indicated for a combination of powdered gold
build-up with a cohesive gold foil veneer.
It is used when access to the lesion is lingual, as dictated by esthetics
and the caries extent, or when the lingual marginal ridge
is lost or undermined.
General shape:
The proximal part of this cavity design will be triangular
with rounded corners. The lingual part may have an incisal or
gingival “turn” as dictated by access and resistance form
Dr.MadhuBilla
109. Location of margins:
Gingival margins of the Loma-Linda preparation are similar
to the Ferrier design.
Labial margins, in some situations, may be located in the contact area,
making the restoration completely inconspicuous.
However, the labial margin will usually have the same locations
and specifications as in the Ferrier design.
The lingual margin will be located far enough onto the lingual surface
to include the marginal ridge and to facilitate access to the internal parts
of the cavity preparation.
Dr.MadhuBilla
110. Internal anatomy:
Inciso-gingival cross-section:
• The loma-linda design appears to have the same anatomy as the
incisal gingival section of the ferrier design, except the line
and point angles are more rounded.
• Also, the incisal internal retention mode appears bulkier than in the
ferrier design.
Labio-lingual cross-section:
if the labial margin is located in the contact area. The labial wall
will be formed of two planes: an enamelo-dentinal plane at
right angle to the axial wall following the directions of the
enamel rods and a partial enamel bevel plane.
Dr.MadhuBilla
111. The point angles gingivally accommodate two cylindrical
retention grooves. They will be directed labio-gingivo-axially
and linguo-gingivo-axially extending about 1.5-2 mm into the
dentin. The incisal retention mode is directed inciso-labio-axial
and is cylindrical in form.
Dr.MadhuBilla
112. INGRAHAM DESIGN
This preparation design is indicated primarily for incipient
proximal lesions in anterior teeth where esthetics is the main concern.
After removal of diseased and undermined tooth structure,
this preparation design will accommodate bulky gingival
and incisal walls. Good oral hygiene, low caries and plaque
indices are essential indications due to the outline of this design.
Dr.MadhuBilla
113. General shape:
This preparation is a simple parallelogram in shape.
Location of margins:
The labial margin of the ingraham design will be in the contact area, so it is
truly invisible labially. The gingival margin just clears the contact area in the
gingival embrasure without any predetermined relationship to the gingiva.
The incisal margin will be within the contact area. The lingual margin
will be on the lingual surface past the marginal ridge, and/or axial angle
of the tooth.
Dr.MadhuBilla
114. INTERNAL ANATOMY:
INCISO-GINGIVAL CROSSSECTION:
At the very labial one-third of the cavity the gingival wall
will have three planes.
An internal dentinal plane, part of a wall accommodating
triangular retention mode, and, inclining apically.
An outer enamelo-dentinal plane following the direction of
the enamel rods; and a peripheral partial enamel plane bevel.
the axial wall will appear to be perfectly flat. the incisal wall
will have the same anatomy as the gingival wall, but in the
reverse direction.
Labio-lingual crosssection:The axial wall appears perfectly
flat, opening directly to the lingual surface and making a right
angle with the labial wall.
Dr.MadhuBilla
115. High quality direct-gold restorations can be ensured
only when four principal conditions are satisfied:
The appropriate gold form is used for each specific
clinical situation.
The material is used only where it is indicated.
A perfectly dry and clean field is provided.
The material is properly manipulated with the correct
instruments.
Philips Textbook of dental materials 11th ed
Dr.MadhuBilla
116. CONCLUSION
The option to utilize gold foil as the best restoration
totally rests on the shoulder of the operator. Unless a
conservative dentist takes a conscious attempt to learn
and master this wonderful material and technique for
many indicated lesions, the patient will be deprived of
the very best treatment because of the fallacy of the
conservative dentist.
Dr.MadhuBilla
117. REFERENCES
Operative dentistry –(modern theory and practice) –m.a.
marzouk
Science of dental materials-(11 th edition)- phillips and
kenneth
William Obrein - 3rd edition
Operative dentistry (3 rd edition) –genard t. charbeneaw
Operative dentistry (3 rd edition )-baum , phillips and lund
Sturdvents operative dentistry 5th edition.
Dr.MadhuBilla
118. SMITH B J OF SOTH CALIFORNIA STATE DENTAL
ASSC. 1959
Advantages of direct gold filling by L.Clarke Operative
dentistry 1985 10-22
Stopfgold: a new direct filling gold. Lambert RL; [Oper
Dent] 1994 Jan-Feb; Vol. 19 (1), p. 16-9.
EZ-Gold The New Goldent By Alperstein , Yearwood Jod
1996,21, 36-41
Dr.MadhuBilla
Obviously, these conditions can only be satisfied if the clinician has acquired the necessary knowledge. skills. and experience. ‘mhe cavity preparation is critically important since it must provide adequate access form. retention. adeq qaate support. well-defined finish lines, and adequate pulp protection
Purity- karat: Number of parts of gold per 24 parts of the alloy
fineness: number of parts of gold per 1000 parts of alloy.
Annealing- a controlled heating and cooling process designed to produce desired properties in a metal.
Cold welding- process of plastically deforming a metal (usually at room temperature ) accompanied by strain hardening
Compaction (condensation) – process of increasing the density of metal foil, pellets or powder using compressive pressure.
Degassing –process of removing the gases (or other impurities ) from solid (or a liquid)
Desorption – process of removing molecules that have attached to the surface of a solid by a physical or chemical action .
Ductile (percentage of elongation )- ability of material to withstand permanent deformation under tensile load without rupture
Malleable- ability of a material to withstand permanent deformation under compressive load without rupture.
Welding – process of fusing two or more metal parts through the application of heat, pressure, or both, with or without a filler metal, to produce a localize union across an interface between the parts.