3. To make individual impressions
for the procedures of prosthetic restorations
Printing for fixed In total impressions
partial prints bridgework (totally or partially
edentulous patients)
For high
accuracy
and fidelity
of detail In
preparation
of single or
multiple
deposit
4. •foundation
Low molecular weight (4,000 approx.)
polysulfide Presence of reactive groups SH mercaptans in the polymer chain
•To give consistency.
Fill best known is titanium dioxide, zinc sulfide
FILLING and silica in proportion 12 to 50%
Lithopone is a white pigment mixture consisting of
zinc sulfide and barium sulfate
Using 3 types of accelerators:
Dioxide or lead peroxide (T rapidly reactivates and environment
THROTTLE
curing reaction is maintained for a longer than others.
Shortening occurs lead peroxide in the polymer chain by
oxidation of the terminal groups SH.
Hidroxiperóxido colorless organic t-butyl or amine activator, with
In order to remove the brown color of lead dioxide.
These compounds have little dimensional stability and contract by the
Evaporation of the volatile constituent of hidroxiperóxido.
Another type is the Cu hydroxide gives a blue-green is better
dimensional stability but may be more toxic than the PbO2 and its product
end is unstable.
5. To facilitate the polymerization of the poly sulfides, sulfur is added
as an advocate
SULFUR Which facilitates the chemical reaction
and stearic acid to assist the polymerization.
DIBUTYLPHTHALATE Is used as a plasticizer
6. Is made between the mercaptan or paste and lead dioxide or accelerator
To give a polysulfide
polysulfide Lead Dioxide polysulfide+ lead sulfide+ water
(base) (acelerador)
(material totalmente polimerizado)
7. Good dimensional stability
to make an impression.
Finish line is clearly visible.
No special equipment.
DISADVANTAGES
Single cell is required.
Not tolerate water in the furrows.
unpleasant odor
8. It is approx. Like 5-7 minutes hydrocolloids
WORKING TIME based on agar-agar and alginates than
The curing time is 8-13 minutes.
It can be modified by several methods:
Higher temperature accelerates the polymerization
CURING TIME Base-rate accelerator: less time basis
accelerates.
Adding a drop of water accelerates the polymerization mixture,
but it is more difficult to mix and monitor their effect.
Adding a drop of oleic acid slows time
polymerization
9.
10. In these materials, the base polymer is a
cyclic ether in terminal groups, imino groups
(triangles are similar to epoxy but with
nitrogen instead of oxygen in a vertex)
11. ▫Polyether based etilenoamina ring terminals.
▫ silica filler.
▫ A plasticizer ftalatode filled with glycol ether.
• Accelerator or catalyst or trigger:
▫ Thinner: Element to provide proper consistency to
the material. Is octyl phthalate and 5% methyl
cellulose.
12. –Flexibility of 3.3%
-Elastic Recovery 99%
-Contraction from 0 .2% 0.3% at 24 hrs
Special Considerations.
-Hydrophilic
13. The two pastes are colors that contrast each other,
which facilitates efficient mixing.
It is important that the print is placed in position and
kept still to avoid tensions that can lead to distortion.
The polymerization is completed in 5 minutes.
14. ▫It comes in a single consistency.
▫ low acceptance is coming in a single consistency.
▫ Its use should only cover up to 4 teeth and these must
not have periodontal disease and being too rigid cause
discomfort to the withdrawal. This aimed at
elaboration of fixed prosthetics (crowns and bridges).
