Junior Dentist

CONDENSATION SILICONES

It was the first type of silicone impression material.
Also known as conventional silicones.
Setting occurs in room temp , so called as RTV silicones.

Composition:
Base paste

Polydimethyl siloxane (hydroxy terminated)
Colloidal silica or micro sized metal oxide filler
putty viscosity – 60-70%
medium viscosity – 35-75 %
low viscosity – 5-15%
color pigments

accelerator paste

alkyl silicate (ortho ethyl silicate)
stannous octate
inert [...]

POLYSULFIDE ELASTOMERIC IMPRESSION MATERIAL:
First elastomeric impression material to be introduced, also known as mercaptan / thymol, it is a type of Rubber based impression material
Supplied as

Base paste (white)
Accelerator (brown/grey)

Available in 3 viscosities:

Light bodied
Medium bodied
Heavy bodied

Composition:
Base paste:

Liquid polysulfide polymer                                         80-85%
Inert fillers (titanium oxide, zinc sulfate, silica)         16-18%

Reactor Paste:

Lead dioxide                                                               60-69%
Dibutyl [...]

Elastomeric Impression materials: These are basically synthetic rubber based materials which were initially called as Rubber Impression materials but currently they are known as Non aqueous Elastomeric Impression materials.
Classification of Elastomeric Impression materials:
Till now the elastomeric impression materials are divided into 3 types based on the material used
1. Polyether
2. Polysulfide
3. Silicone

Addition
Condensation

POLYETHER IMPRESION [...]

As i mentioned already in the earlier post the Guidelines to the Perfect Impression this post is just an addition where the precautions to be taken are given in a different was so that it is easy for the Dental assistant and the Clinician to get a perfect dental impression.
Tips for the Dental Assistant

Apply the [...]

Alginate Impression material is an Elastic, Irreversible Impression material which is used to take the impression  of both Dentulous and Edentulous Impressions.
TYPES:
Type I fast setting : 1-2 min.
Type II normal setting : 2-4.5 min.

Available as :

1. Bulk powder
2. Preweighed packages
3. Color changing alginates: violet during mixing, pink when ready to be [...]