Classification of Impresssion Materials-Prosthetic Dentistry Lecture Note

Impression Materials
Classification Depend on Viscosity

High Viscosity

• Impression Compund
• Putty Elastomers

Medium Viscosity

• Regular Elastomers

Low Viscosity

• Impression Plaster
• Impression Paste
• Hydro colloids(Reversible,Irreversible)
• Light Body Elastomers

Classification Depend on Elasticity

Elastic Materials

• Synthetic Elastomers(Polysulfides,Silicones,Poly Ether)
  
• Hydrocolloids(Reversible-Agar,Irreversible-Alginate)

Non Elastic Material

• Impression Compound
• Zinc Oxide/Eugenol Paste
• Impression Waxes
• Impression Plaster

Impression materials are used to record the shape of the teeth and alveolar ridges. There are a wide variety of impression materials available each with their own properties, advantages and disadvantages. Materials in common use can be classified as elastic or non-elastic according to the ability of the set material to be withdrawn over undercuts.