Dental impression compound is a thermoplastic material used to make impressions in dentistry. It comes in cake or stick form and is composed of a thermoplastic material, filler, and plasticizer. Impression compound softens when heated and hardens upon cooling, allowing it to accurately record tooth positions and jaw structures. While inexpensive and easy to use, it has disadvantages like inability to capture undercuts, fine detail, or dimensional accuracy over time.

1. Dental Impression Compoun
d
NEW MANSOURA
UNIVERSITY
Faculty of Dentistry
Course Code: PDD132

2. Definition & Types
Dental Impression Compound Thermoplastic material
Non elastic&muco compressive
I (impression): low fusing (soften at 45°-55°C) used to
Types record (primary impression & tracing)
II (tray): high fusing (soften at 70°C) used as tray

3. Uses
1- Primary impression for edentulous patients.
2- Modeling or tracing of special acrylic tray.
3- Support other impression material (tray for wash impression).

4. Packaging (form) &
Composition
• Packaging:
It may be Cakes or Sticks.
• Composition:
1- Thermoplastic material: for
thermoplasticity and flow.
2- Filler: for giving body & suitable working
time.
3- Plasticizer: for lubrication &
control consistency.

5. Reaction & Manipulation of cakes
• Reaction:
Physical (Thermoplastic) & Reversible reaction
• Manipulation of cakes:
1- Softening & wet kneading then load it to stock tray.
2- Insertion in patient's mouth.
3- After cooling, separate the cast using warm water.

6. Manipulation of sticks
1- Soften by holding the stick above the flame.
2- It should be tempered in air or cold water.
3- Tracing borders of the tray.

7. Properties
1- Thermostatic Behavior
2- Flow
3- Thermal conductivity
4- CTE
5- Residual stress

8. Causes of
warpage
1- Residual stress.
2- Incomplete homogenous
softening.
3- Removal of impression material
before complete hardening.
4- Delaying in pouring the
impression.

9. Advantages
1- Easy manipulation.
2- not expensive.
3- Adequate
4- No separating mediam.
5- Can be electroplated by copper.

10. Disadvantage
1- Can't
reproduce
under cuts.
2- Doesn't
record fine
details.
3- Non
hyghienic.
4- Dimential
changes.