Post on 19-Feb-2022
Classification of the working cast and die
systemsI-Working cast with separate die.
II-Working cast with removable die:
A. DowelPinTechnique.
B. DI-LOCK Tray Technique.
C. Pindex System.
D. DVA system. E. Zeiser system.
III-Single Die Technique:
Stone die - Amalgam die - Acrylic die - Refractory die (Ceramic
die) - Flexible die - Electroplated die: Silver plated or Copper
plated.
A. Dowel Pin Technique
A ball of soft wax is placed on the dowel pin tip and
application of separating medium.
Classification of the working cast and die
systemsI-Working cast with separate die.
II-Working cast with removable die:
A. Dowel Pin Technique.
B. DI-LOCK Tray Technique.
C. Pindex System.
D. DVA system. E. Zeiser system.
III-Single Die Technique:
Stone die - Amalgam die - Acrylic die - Refractory die (Ceramic
die) - Flexible die - Electroplated die: Silver plated or Copper
plated.
B. Die-lock tray
-It is a snap apart plastic tray which has an
internal orienting grooves and notches that
help to assemble the working cast and die.
B. Die-lock tray
-Technique
● The tray is filled with a new mix of dental stone.
● The U-shaped cast is seated in the tray on the stone mix.
● The cervical line of the teeth should be 4 mm above the tray
edge.
B. Die-lock tray
-Technique
After stone hardening, the tray is dis-assembled and the cast is
removed from the tray.
B. Die-lock tray
-Technique
● A saw cut is made on each side of the prepared tooth.
● The die is separated from the cast by finger pressure.
Classification of the working cast and die
systemsI-Working cast with separate die.
II-Working cast with removable die:
A. Dowel Pin Technique.
B. DI-LOCK Tray Technique.
C. Pindex System.
D. DVA system. E. Zeiser system.
III-Single Die Technique:
Stone die - Amalgam die - Acrylic die - Refractory die (Ceramic
die) - Flexible die - Electroplated die: Silver plated or Copper
plated.
C. Pindex system
It is similar to a dowel pin system but create a working cast
with dies with great precision.
● Mixing stone:
A correct stone powder/water ratio is mixed in a
mixing bowel using a vacuum mixing unit.
● Pouring The impression:
The impression is held on the vibrator and poured
with a proper mix of stone from one side using a
spatula.
● All crowns, bridge units and adjacent teeth should
be pinned.
● The rest of the dental arch should also be
supported by at least two dowel pins.
● The cast is placed on the pindex machine and the
pilot light is used as a guide to drill holes in the base
of the cast.
● The platform of the pindex machine is spring
loaded. When the cast is pressed against the
platform, the motor will get activated to drill a hole in
the base of the cast.
● After applying a separating medium at the base of
the cast, the pins are coated with the stone on the
vibrator.
● After setting of the stone base, the rubber base
former is removed. Saw cuts follow the marked
segments of the cast using a hand saw.
Computer Aided Design (CAD)
CAD is the process of using
software to assist in precision
drawing and designing models to
aid in their manufacturing.Computer Aided
Manufacturing (CAM)CAM is the process of using
software to analyze and
manufacture models.
Digitizing : is the use of a 3D measurement
system to capture features ( gather data ) of
a n o b j e c t .
Digital Modeling : is the process of creating
a computer model of an object that exactly
repl icates the form of that object .
Digitizing
What is RP ?
An additive manufacturing
process that creates an object
directly from a CAD model by
building it in layers
Selective Laser Sintering (SLS)
◼ It uses laser to draw cross-sections in a bed of fine,
heat-fusible powder. The laser raises the temperature of
the powder particles momentarily to where they sinter
(“Sintering,” means welding without melting.).
◼ SLS works with a broad range of materials powder,
including thermoplastics, metal powder, casting wax
and ceramic powder.
Fused Deposition Modeling (FDM)
◼ FDM acts like a finely controlled hot-melt glue
gun. But instead of glue, FDM gingerly extrudes
an ultra thin layer of thermoplastic filament.
◼ Actually, two filaments are extruded: one for the
model and the other for the undercut/overhang
support.
◼ No laser is involved.
Three-Dimensional Printing (3DP)
◼ Imagine an ink-jet printer. Now think of it producing
3D prototypes instead of printed pages. That’s the 3DP
technology.
◼ No laser is involved.