Module 3: Flexible Impression Materials (Lab)

Alginate/Alginate Hydrocolloid

It is an irreversible impression material.

Alginate/Alginate Hydrocolloid

It was developed as a substitute for the agar impression material when its supply became scarce during World War II.

Agar

Alginate was developed as a substitute for which impression material when its supply became scarce during World War II?

Alginate/Alginate Hydrocolloid

This material is based on a natural substance from a certain brown seaweed.

Anhydro-B-d-mannuronic Acid / Alginic Acid

Alginate substance is also called (2)?

Manual Mixing - Mechanical Mixing

Mixing the alginate impression material can be done in two ways, which are?

38ml / 16 g

The ideal water to powder ratio is?

Imbibition - Syneresis

What are the 2 dimensional changes in alginate?

Imbibition

The absorption of water into the surface of the gel causing swelling.

Syneresis

The evaporation of water form the surface of the gel causing shrinkage.

Elastomers

Rubber-like in nature, ADA specification #19 has non-aqueous elastomeric dental impressions, basically synthetic rubbers and initially they were called rubber impression materials.

Elastomers

These are used where a high degree of accuracy is needed, especially in crown and bridge work.

Rubber Impression Materials

Elastomers were initially called?

Good Tear Resistance - Dimensional Stability

What are the two main advantages of elastomers over hydrocolloids?

Elastomers

They are mainly hydrophobic rubber-based materials.

Silicone Impression Materials

They tend to be more favorable in dental use than other elastomeric impression materials.

Hand Mixing - Static Mixing - Dynamic Mechanical Mixing

What are the 3 modes of mixing elastomeric impression materials?

Catalyst Paste

(Hand Mixing) It is first collected on a stainless steel spatula and then spread over the base paste.

Cartridge

(Static Mixing) It is inserted into the gun and the cap on the end is removed.

Plungers

(Static Mixing) Are advanced by the trigger until the base and catalyst are extruding uniformly.

Trigger

(Static Mixing) Is used to extrude and mix the base and catalyst through the mixing tip.

Impeller

(Dynamic Mechanical Mixing) Motor-driving mechanism forces the material into the mixing tip and makes the ________ rotate.

Impeller

(Dynamic Mechanical Mixing) The ________ inside the tip functions to mix the material.