LECTURE 9: DIRECT GOLD RESTORATIOn Flashcards
DIRECT GOLD
two types for dental use:
o gold foil
o powdered gold
→ superior restorative material
→ can last a lifetime
→ superb biocompatibility with oral environmen
DIRECT GOLD
T/f
Direct gold has an excellent marginal integrity
T
T/f
DIRECT GOLD INDICATIONS:
teeth abraded, eroded or has abfraction on facial surfaces of
teeth
T
INDICATIONS:
All classes with small cavitated tooth EXCEPT class IV
DIRECT GOLD
T/f
DIRECT GOLD is contraindicated with root canal filled teeth, handicapped patients unable to sit for a long appointment
T
T/f
DIRECT GOLD is contraindicated for teeth with very large pulp chambers, severe periodontally weakened teeth, economics
T
T/f
gold foil is manufactured by beating pure gold into thin sheets
T
the 4x4 inch sheets of gold foil are too large to use in restorative procedures that is why it is rolled into ______ or ___ before insertion
into tooth preparations
cylinders, pellets
GOLD FOIL pellets are rolled from:
o 1/32 inch
o 1/43 inch
o 1/ ___inch or
o 1/128 inch
64
damp cotton pellet with ________ into each box section to prevent deleterious oxides from forming on gold
18% ammonia
combination of chemical precipitation and atomization, with an average particle size of 15 mm
A. GOLD FOIL
B. POWDERED GOLD
B
marketed as Williams E-Z Gold
A. GOLD FOIL
B. POWDERED GOLD
B
atomized particles are mixed together in wax, cut into pieces, and wrapped in no. 4 or no. 3 foil
A. GOLD FOIL
B. POWDERED GOLD
B
T/f
the gold must be in a cohesive state before compaction
T
gases must be removed from the surface of the gold before dental compaction accomplished by heat application; desired result is to remove residual surface contamination
degassing/annealing
accomplished by heating the gold foil on a mica tray over a flame or on an electric annealer or by heating each piece of gold over a pure 2. _____ flame
- degassing/annealing
- ethanol
T/f
all direct-filling gold products are degassed immediately before use
T
gold is passed into the blue inner core of the flame on the tip of a foil passing instrument and held just until the gold becomes dull ____; then the instrument is withdrawn from the flame–after a few seconds are allowed for cooling, the gold is placed in the preparation
red
preferred technique:
o___ to deliver light blows to a condenser held by the dentist → allows great control of malleting forces and allows for rapid change in condenser nibs, or tips, when a multitude of condensers is required
hand mallet
designed to deliver forces of compaction to direct gold
condensers
rectangular face that is
approximately 1-1.3 mm
varney foot condenser
which are used only for hand
pressure compaction and nib faces that measure
approximately 0.5-1 mm
parallelogram condensers
may be straight, monoangled, or off-set and their nib faces may be cut perpendicular to the long axis of the handle or perpendicular to the end portion of the shank
condenser shanks
T/f
the smaller the nib face size, the greater the pounds per square
inch delivered
T
for most gold, the _____ mm diameter nibs are suitable
0.4-0.55
T/f
smaller condensers tend to punch holes in the gold, whereas
larger ones are less effective in forcing the gold into angles in
the tooth preparation
T
two fundamental principles involved in compaction of cohesive gold:
o to weld the gold into a cohesive mass
o wedge as much gold as possible into the tooth preparation
T/f
correct hand-malleting technique requires a light, bouncing application of the mallet to the condenser
T
the first pellet of E-Z Gold is pressed into the depth of the tooth preparation and tamped into position using an ____
amalgam condenser or a gold foil condenser
margins must not be ragged
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
A
→ established on sound areas of the tooth
→ include all structural defects
→ marginal outline must be designed aesthetically pleasing (visible
restoration)
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
A
flat pulpal floor perpendicular to occlusal forces
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
B
all enamel must be supported by sound dentin
→ optimally placed axial or pulpal walls promote integrity of
restored tooth providing suitable thickness of remaining dentin
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
B
parallelism of some walls and by strategically placed converging walls
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
C
→ smooth and flat walls
→ sharp internal line angles
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
C
requires suitable access and a dry field
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
D
sharp internal line and point angles are created in dentin to
allow convenient “starting” gold foil as compaction begins
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
D
rounded form is permitted when E-Z Gold is used to begin the restorative phase
removal of remaining carious dentin, final planing of cavosurface margins, and debridement
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
D
→ extended to include lesions as well as any fissured enamel
→ simple circular design for a pit defect, or oblong, triangular or a
more extensive form
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
A
in extensive occlusal preparations, the mesial or distal wall or walls (or both) may ___ slightly occlusally to avoid undermining and weakening marginal ridges
A. diverge
B. converge
A
a very slight cavosurface bevel may be placed to:
o create a 30-40 degree metal margin for ease in finishing
the gold
o remove remaining rough enamel
→ the bevel is not greater than 0.2 mm in width
A. OUTLINE FORM
B. RESISTANCE FORM
C. RETENTION FORM
D. CONVENIENCE FORM
A
Type of bur is aligned and the outline form and initial depth is established
no. 330 or no. 329
the gold is compacted into the pulpal line angles and against the external walls and the line of force is changed to a __-degree angle to the pulpal and respective external walls
45
if gold foil is selected to veneer this restoration, ___ of suitable size are selected
pellets
a flat ______ burnisher is used with heavy hand pressure to harden the surface gold
beaver-tail
a ___carver is used to continue the burnishing process
and remove excess gold on the cavosurface margin
cleoid-discoid
no. ____ retainer or gingival retractor in CLASS V TOOTH PREPARATION AND RESTORATION
212
T/f
mesiodistal curvature of the axial wall prevents encroachment of
the tooth preparation on the pulp
T
refines occlusal wall and margin
Wedelstaedt
other suitable serrated condensers are used to firmly force the gold against the axial wall and to wedge it into the line angles
parallelogram foil condensers
