681. Rough and irregular surface produced on the impression is because of_______________?
A. Improper application of pressure during impression making
B. Air incorporated during mixing
C. Presence of excessive saliva in impression area
D. Due to improper ratio of polymer and monomer
682. Minimum flow of Type-I impression compound at mouth temperature is___________________?
683. Polysulfide material is routinely not recommended because of_______________?
A. Unpleasant odor and taste
B. Least permanent deformation
C. Low accuracy
D. Highest curing shrinkage
684. Hydrocolloid material, show all except______________?
685. Impression material that Do NOT harden by chemical reaction_______________?
B. Impression compound
C. Zinc oxide eugenol
D. Plaster of paris
686. Putty wash technique_________________?
A. Light body first and putty later
B. Putty used first and light body used second
C. Light body and putty used at the same time
D. None of the above
687. What is the minimum thickness of the elastomeric impression material for an accurate impression_______________?
A. 2-4 mm
B. 2 mm
C. Greater than 3 mm
D. Maximum in the area of operation
688. The relative hardness of elastomere is determined using________________?
A. Barcol indenter
B. Rockwell tester
C. Knoop pyramid
D. Shore durometer
689. Rough surface of elastomeric impression results from_______________?
A. Air bubbles
B. Inadequate mixing
C. Too rapid polymerization
D. Incomplete polymerization caused by premature removal from mouth
690. Most rigid elastomer is___________________?
B. Addition silicone
D. Condensation silicone