Material
What makes impression compound thermoplastic?
Resins and waxes
Setting reaction of ZOE is a
Chelation rxn, acid base rxn
First thermoplastic material
Impression Compound
Alpha modified crystals are obtained by
Wet calcination in presence of modifiers such as CaCl2,MgCl2
What type of material does this graph portray?
Brittle material
What happens on over heating of impression compound
Loses its properties
What is working time?
time from start of mixing till the mat becomes no longer usable
First material used for impression making
Impression plaster
Why should dental plaster not be used for primary cast in alginate impression?
because it is too soft to pour alginate impression
Property of alginate which determines its ability to withstand tearing on removal
Tear strength
Eugenol in ZOE impression paste belongs to which functional group
Phenol
Effect of use of warm water on alginate
accelerates ST
Alginate was originally derived from
Brown seaweeds
ZOE is avoided in patients because of its which component?
Eugenol
Material loss due to mechanical wear by frictional forces
Abrasion
What does this image show
Triple tray
Dual impression technique is also called as
Laminate technique, Agar-alginate technique
Material which replaced POP for primary impression material due to its elasticity
Alginate
Impression compound
Change in dimension of impression material with temperature is called
Thermal coefficient of expansion
Explain the ion exchange movement in alginate
Explain Setting rxn of alginate
Vigorous spatulation of gypsum products leads to increased formation of _____ thereby ______ setting time
nuclei of crystallization, decrease
Before elastomers which material was used as secondary impression material ?
ZOE impression paste
ZOE is ideal for which type of ridge
Resorbed and without undercuts
Time dependant deformation under constant lead is called
Creep