291. Wash or corrective impression is done by______________?
A. Impression plaster
B. Impression paste
C. Alginate
D. Rubber base impression material
292. The plasticizers used in polyether impression material is_______________?
A. polyether polymer
B. Colloidal silica
C. Glycol ether
D. Di-vinyl poly (dimethyl siloxane)
293. In reversible hydrocolloid the property by which the transformation from sol to gel and gel to sol is a function of the_____________?
A. Concentration of filler and plasticizer
B. Percentage composition by weight of water
C. Concentration of potassium sulphate
D. Temperature
294. Alginates are_____________?
A. Sol
B. Gel
C. Hydrocolloid
D. Colloid
295. Syneresis is associated with______________?
A. Hydrocolloids
B. Elastomers
C. Zinc oxide eugenol
D. Plaster of paris
296. The advantage of ZOE impression paste_______________?
A. Has dimensional stability
B. Does not adhere to tissues
C. Is easy manipulation
D. Does not require special trays
297. Rinsing of the impression is important to________________?
A. Remove excess impression material
B. Remove saliva
C. Hydrate the impression
D. Accelerate the setting
298. Which is best material for RPD impression_______________?
A. Impression plaster
B. Irreversible hydrocolloid
C. Reversible hydroollioid
D. None of the above
299. Which of the following is not affected by saliva ?
A. Impression plaster
B. Impression paste
C. Silicon impression material
D. None of the above
300. Retarder in Zinc oxide eugenol is______________?
A. CaCl2
B. Zinc acetate
C. Alcohol
D. Glycerine