Impresion Material Flashcards
What are the non elastic materials?
Impression wax
Impression plaster
Zn O eugenol
Impression compound
How can we classify impression material?
Elastic and non elastic
How can we classify elastic impression materials?
Elastomer
Hydro colloid
What are the hydro colloids?
Alginate
Agar
WHat are the elastomers?
Polyether
Silicone
Polysulfide
What are the silicones?
Addition and condensation
What is the purpose of an impression material?
To produce an accurate replica of the hard and soft tissues
When can you use ridgid materials?
When there are no boney undercuts so edentulous
When can you use elastic impression materials?
Can engage in undercuts
When is impression compound used?
Modify stock trays and special trays and used as a foundation for a wash impression
Wha pt type of material is impression compound?
Thermoplastic
What are the two type of impression compound?
Type 1: lower fusing impression material
Type 2: higher fusing tray material
What temp is impression compound softened at?
55-60 degrees
What is the molecular weight of alginate?
20000-200000
What is alginate based upon?
A colloidal suspension of mucopilysaccahirdes in water
Alginic acid
What states does alginate exist in in dentistry?
Gel and sol state
What is the molecular structure of alginate?
Polymer
What is the setting reaction for alginate?
Sodium alginate + calcium sulphate -> sodium sulphate + calcium alginate
Calcium forms cross linking between polymer chains to form a 3d network
What is the constituent of alginate?
Few: fillers : 52% Soldiers: sodium alginate 18% Can: calcium sulphate dihydrate: 14% Pass: potassium suplphate: 10% Simple: sodium silicofluroide: 4% science: sodium Phosohate : 2%
What is the purpose of the fillers in alginate?
Controls consistence