TỔNG ÔN TẬP THI VÀO LỚP 10 MÔN TIẾNG ANH NĂM HỌC 2023 - 2024 CÓ ĐÁP ÁN (NGỮ Â...
Elastomers for dental uses
1.
2. Elastomers
(polysiloxanes) :
Used to identify materials with a particular
structure. Are organic materials consisting
of polymer molecules with the ability to
"stretch", "develop," compressed
"ultimately bear to tensions mouth.
3. Chemically there are four types of
elastomeric impression materials used as:
1.Polisulfure
2. Silicone condensation polymerization
3. Addition polymerization silicone
4.Polyether
5. According to the reaction to which they are
subject to change to a plastic state
Those who change their status in a physical
reaction, it is to say, which do not change
their properties, only its consistency when
subjected to heat.
. Wax printing
. Model compounds or Godivas
.reversible hydrocolloid
7. Classification according to their
behavior during setting, hardening or curing.
elastic:
. Mercaptans.
. Elastomers silicones.
. Polyethers.
rigid:
Model compounds or góbidas.
Waxes.
Casts.
8. characteristics to be met by printing
materials to be considered optimal
for management
Easy to handle.
. Compatibility with oral tissues.
. There are irritating.
. Not allergic.
. Taste and look nice mix.
low cost.
. that when subjected to disinfecting
solutions preventing alterations
. Hydrophilic Where possible, that does
not affect the presence of moisture
9. Use of elastomers in odontology :
1 PLAY STRUCTURES WITH HIGH
FIDELITY MOUTH.
Fig#5
10. 2. OCCLUSAL RECORDS MAKE OR BITE,
ACCURATE .
http://expodenta
l.wordpress.com
Fig#6
3 OTHER USES : MISMATCH INDICATOR OF
RESTAURATIONS
Fig#7
http://www.slideshare.net/yuritek/elasto
m2005-presentation
11. - PRINTING MATERIAL
FOR DUPLICATE MODELS
http://www.slideshare.net/yu
ritek/elastom2005-
presentation
Fig#8
12. Silicones:
Elastic materials
are based impressions polydimet
hyl siloxanes orpolyvinyl siloxan
http://www.dentald es. They owe their name to
eml.com/catalogo/c the presence of silica and
ubetadealuminio.ht oxygen in its composition
m
FIG#9
13. Uses: prints are used for crowns and fixed
bridges For bite registration and laboratory
procedures for the process of partial and full
dentures.
Fig#17
Fig#18
14. Condensation silicone
composition
polydimethylsiloxane
Ethyl ortho silicate
Silica filler
CATALYST : Tin octoate
Tin octoate
Silicone Rubber
ethyl alcohol.
The chemical reaction of a condensation silicone is as follows
silicate ortoalquílico
polydimethylsiloxane+ silicate ortoalquilico ----
polydimethyl siloxane + Alcohol
15. PROPERTIES:
. The working time of the silicones is 2-
4 minutes less than the mercaptans
Polymerization time: 6-
3 minutes is comparatively less than the
mercaptans, the polymerization time can be
changed with
temperature temp. High polymerization acce
lerates
Dimensional Stability: Like other print
materials, condensationsilicones contract.
. Can be reduced using well
adapted trays with a thickness of 3 to 4mm.
16. . Elastic recovery: the recovery is
approximately 100% higher than virtually all
other elastic materials.
Fluency: compared with the mercaptans,
these materials are morerigid and therefore
have better flow.
Flexibility: inflexible compared to the
mercaptans and more flexible than the
polyesters
Toxicity of silicones are not toxic, however it
is recommended not to touch his hands and
not take material improperly
mixedimpressions.
17. easy handling .Sensitive to high
.It is stable over temperatures
short periods of time .Evaporation of alcohol
.Have different elastic .Short working
properties time for multiple prints
.Can be prepared .Greater contraction of
with different polysulfides
viscosity resists .Short life
displacement of the
gingival tissues
.It has pleasant taste
and odor
