3. INTRODUCTION
DEFINITION:
ELASTOMER:
A lightly cross linked impression material that exhibits elastic
behaviour after setting.
They are chemically or physically cross linked.
They can be easily stretched and rapidly recover their original
dimension when the applied stress is released.
ADA specification no:19
5. POLYSULFIDE
First synthetic elastomeric impression material.
Also known as Mercaptan or Thiokol.
Supplied in dispensing tubes.
Base paste and catalyst paste
Consistencies:
Light body
Medium body
Heavy body
6. COMPOSITION
BASE PASTE:
Polysulfide polymer.
Filler-Lithopone or Titanium dioxide.
Plasticizer- Dibutyl phthalate.
0.5% Sulfur
CATALYST PASTE:
Lead dioxide
Retarder- Oleic acid or stearic acid .
PHILIPS SCIENCE OF DENTAL MATERIALS 11 TH EDITION
9. • In vitro investigation have shown that the impression
material can penetrate and remain entrapped inside
the dentinal tubules during the impression
procedures(FPD).
• This aspect might have a negative influence on the
adhesion, and thus this study strongly supports the
use of an immediate dentine sealing procedure for
adhesive restorations.
Penetration of Different Impression Materials into Exposed Dentinal Tubules during the
Impression Procedure Bruna Sinjari , Gianmaria D’Addazio , Edit Xhajanka , Sergio Caputi ,
Giuseppe Varvara and Tonino Traini
10. • Sinjari et al demonstrated how an adequate
surface cleaning protocol can reset the
interactions with the impression material.
• In their study, they proposed that following
the adhesion protocol, the surface should be
cleaned with prophy paste and a surfactant
agent (e.g., Marseille soap).
Sinjari, B.; D’Addazio, G.; Murmura, G.; Di Vincenzo, G.; Semenza, M.; Caputi, S.; Traini, T.
Avoidance of interaction between impression materials and tooth surface treated for immediate
dentin sealing: An in-vitro study. Materials (Basel) 2019, 12, 3454.
11. MODIFICATIONS
Lead dioxide is replaced by cumene
hydroperoxide or t- butyl hydroperoxide.
A recently developed polysulfide replaces the
lead dioxide by a zinc carbonate / organic
accelerator system.
E.C .COOMBE NOTES OF DENTAL MATERIALS 6TH EDITION
12. CONDENSATION SILICONE
First type of silicone impression material .
Otherwise known as conventional silicone.
If the setting occurs in room temperature then it known as
RTV.
MODE OF SUPPLY:
Collapsible tubes.
Base paste
Accelerator low viscosity liquid
Putty supplied in jars.
20. • Sulfur as a reactive element contained within
latex gloves or rubber dam material may react
with chloroplatinic acid catalyst in elastomeric
impression material, even with concentrations
as low as 0.05% may totally inhibit the
polymerization reaction.
• The vinyl glove did not inhibit the
polymerization of the addition silicone
An Evaluation of the Effect of Various Gloves on Polymerization Inhibition of Elastomeric
Impression Materials: An In vitro Study
Vinuta Hiremath, G. Vinayakumar,Mallikarjuna Ragher,Sounyala Rayannavar, Mahantesh
Bembalagi, and B. L. Ashwini Journal of pharm bioalligned sciences 2017,nov 9
21. • siloxanes cured by the thiol-ene reaction
displayed highly accurate detail reproduction
and greater mechanical strength would be
achieved through variable filler loading, would
prove a superior impression material in clinical
dentistry
Thiol-ene functionalized siloxanes for use as elastomeric dental impression materials Megan A.
Cole a, Katherine C. Jankousky a, Christopher N. Bowmana,b. Dental materials 13 2014 (449-
455)
22. POLYETHER
First elastomer to be developed primarily to
function as impression material.
Supplied in tubes.
Base paste.
Accelerator paste.
23. COMPOSITION
BASE PASTE:
Polyether polymer.
Inert filler – silica.
Plasticizer- Glycolether or phthalate.
CATALYST PASTE:
Alkyl aromatic sulfonate.
Inert filler – silica.
Plasticizer- Glycolether or phthalate.
PHILIPS SCIENCE OF DENTAL MATERIALS 11 TH EDITION
31. IMPRESSION TRAYS
• The use of a custom tray is recommended to
reduce the quantity of the materials used to
make impressions with polysulfide.
• Disposable stock trays work satisfactorily for
polyether and addition silicone when the
putty-wash technique is used for making
impressions.
33. HAND MIXING
• Equal length of catalyst and base paste are
dispensed on a paper pad.
• The mixture is spread over the mixing pad.
• The mass is then scraped up with the spatula blade
and spread uniformly back and forth on the mixing
pad.
• Mixing time 45 secs.
34. STATIC AUTOMIXING
• Base and catalyst are in separate cylinders.
• Catridge placed in mixing gun containing 2 plungers
• Equal amount of both pastes forced through static
mixing tip.
• Mixed material can be extruded directly either into
impression tray or onto the prepared tooth.
35. DYNAMIC MECHANICAL MIXING
• Catridge is inserted into the top of mixing machine.
• A new plastic mixing tip is placed on the front.
• On pressing the button parallel plungers push against the
plastic bags ,thus opening the bags.
• Material is forced into the
dynamic mixing tip .
mixing done by rotation +
Forward motion through spiral.
37. DUAL VISCOSITY TECHNIQUE
• Low consistency material is injected with a syringe
into and around the critical areas.
• High consistency material is mixed and placed in the
tray.
38. MONOPHASE TECHNIQUE
• Only one mix is made part of it placed in a tray.
• Another portion placed in syringe for injection.
• Medium viscosity of addition and polyether can be
used.
39. PUTTY WASH TECHNIQUE
Developed for condensation silicone to minimize the effect of
polymerization shrinkage on the dimensional changes.
Two approaches can be used: a two-stage procedure and a
single-stage procedure.
TWO STAGE PROCEDURE:
• Thick putty material is placed in a stock tray and a preliminary
impression is made.
• After preparation light body is syringed into the prepared
tooth and the preliminary impression is reinserted and the
impression is made.
40. SINGLE STAGE PROCEDURE:
• The wash material is syringed into place, and then
the unset putty is scaled over the light-body
material.
• Occlusal stops should be used in the tray to avoid
pushing through the wash or syringe material.
41. REMOVAL OF IMPRESSION
• All elastomeric impression materials are
viscoelastic, and it is necessary to use a quick
snap to minimize plastic deformation of the
impression during the final step of the
removal process.
42. MATERIAL METHOD RECOMMENDED
DISINFECTANT
COMMENTS
POLYSULFIDE IMMERSION Glutaraldehyde , chlorine
compounds , iodophors ,
phenolics
Not > than 30 mins.
CONDENSATION
SILICONE
IMMERSION Same as polysulfide Not > than 30 mins.
ADDITION SILICONE IMMERSION Same as polysulfide Not > than 30 mins.
POLYETHER Chlorine compounds and
iodophors.
Short term
exposure < 10
mins.
DISINFECTION
43. The dimensional changes of polyether impression after
disinfection and prolonged storage complied with
ANSI/ADA standard.
The tested polyether impression materials were
dimensionally stable for clinical use after disinfection for
30 minutes in glutaraldehyde and storage for up to 2
weeks.
The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl
polyether silicone impression materials Usama Nassar*, Carlos Flores-Mir, Giseon Heo,
Ysidora Torrealba J Adv Prosthodont 2017;9:182-7
44. PREPARATION OF STONE CASTS AND
DIES
• All non aqueous elastomeric impression
materials are compatible with all types of
gypsum products during the setting of the
gypsum products.
• The time interval between impression pours
should not be greater than 30 minutes.
45. FAILURES
ROUGH OR UNEVEN SURFACE
DISTORTION ROUGH OR CHALKY STONE CAST
IRREGULARLY SHAPED VOID
BUBBLES
46. CONCLUSION
The understanding of basic knowledge of the
impression materials and their behaviour
during handling are important for their use in
oral environment and clinical success.
The selection of the material best suited for
particular clinical situation and technique
rests with the operator.
47. REFERENCES
1. PHILIPS science of dental materials.
2. CRAIGS restorative dental materials 12th edition.
3. E.C.COOMBE Notes on dental materials 6th edition.
4. Penetration of Different Impression Materials into Exposed Dentinal Tubules during the
Impression Procedure Bruna Sinjari , Gianmaria D’Addazio , Edit Xhajanka , Sergio Caputi
,Giuseppe Varvara and Tonino Traini
5. Sinjari, B.; D’Addazio, G.; Murmura, G.; Di Vincenzo, G.; Semenza, M.; Caputi, S.; Traini, T.
Avoidance of interaction between impression materials and tooth surface treated for immediate
dentin sealing: An in-vitro study. Materials (Basel) 2019, 12, 3454.
6. An Evaluation of the Effect of Various Gloves on Polymerization Inhibition of Elastomeric
Impression Materials: An In vitro Study
7. ViBembalagi, and B. L. Ashwini nuta Hiremath, G. Vinayakumar,Mallikarjuna Ragher,Sounyala
Rayannavar, Mahantesh Journal of pharm bioalligned sciences 2017,nov 9 .
8. The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether
silicone impression materials Usama Nassar, sCarlos Flores-Mir, Giseon Heo, Ysidora Torrealba J
Adv Prosthodont 2017;9:182-7.
9. Thiol-ene functionalized siloxanes for use as elastomeric dental impression materials Megan A.
Cole a, Katherine C. Jankousky a, Christopher N. Bowmana,b. Dental materials 13 2014 (449-455)
.
