Chapter 16 Gypsum and Wax Products
1. B - Dental Stone: Carefully controlled calcination under steam
pressure in a closed container produces
A. plaster
B. dental stone
C. high strength stone
D. high strength, high expansion stone
2. C - Increase the water temperature: To decrease the working
time of a gypsum product, with-out changing any physical
properties, it is best to
A. decrease the water-to-powder ratio
B. increase the rate of spatulation
C. increase the water temperature
D. decrease the water temperature
3. C - particle size and shape: The main difference between
model plaster and dental stone is A. chemical formula
B. solubility in water
C. particle size and shape
D. accelerators and retarders
4. C - Type 3: The most appropriate type of gypsum product to
use for orthodontic casts is A. Type 1
B. Type 2
C. Type 3
,D. Type 4
5. A - Loss of gloss: Initial setting can be detected clinically by
A. loss of gloss
B. the end of the exothermic reaction
C. a change in color
D. testing to see whether the material is hard enough to separate
from the impression6. C - anatomic portion: The area of the
diagnostic cast that records the hard and soft tissues is called the
A. art portion
B. base
C. anatomic portionD. impression
7. A - both statements are true: A study model is a positive
reproduction. An impression is a negative reproduction.
A. both statements are true
B. both statements are false
C. the first statement is true, the second statement is false
D. the first statement is false, the second statement is true
8. A - saliva: Material that will act as retarders for the set of
gypsum products include A. Saliva
B. Set gypsum products
C. slurry water from the model trimmer
D. non of the above are considered retarders
, 9. D. A and B: It is important to consider the following statements
when pouring an impression
A. alginate impressions should remain unseparated from the
model for only 1 hour B. when the single-step method is used, the
material poured into the impression must reach the initial set
before the base is poured
C. Gypsum should be mixed as wet as possible to allow for
sufficient working time D. A and B
E. A and C
10. A - patient education: Diagnostic casts are used for
A. patient education
B. fabricating dentures
C. fabricating crowns
D. fabricating orthodontic appliances
11. E - A and C: CAD/CAM fabrication of indirect restorations
eliminates the need for
A. investing
B. cutting the preparation
C. impression taking
D. A and B
E. A and C
12. B - the point at which the wax softens: The melting range
can best be described as
1. B - Dental Stone: Carefully controlled calcination under steam
pressure in a closed container produces
A. plaster
B. dental stone
C. high strength stone
D. high strength, high expansion stone
2. C - Increase the water temperature: To decrease the working
time of a gypsum product, with-out changing any physical
properties, it is best to
A. decrease the water-to-powder ratio
B. increase the rate of spatulation
C. increase the water temperature
D. decrease the water temperature
3. C - particle size and shape: The main difference between
model plaster and dental stone is A. chemical formula
B. solubility in water
C. particle size and shape
D. accelerators and retarders
4. C - Type 3: The most appropriate type of gypsum product to
use for orthodontic casts is A. Type 1
B. Type 2
C. Type 3
,D. Type 4
5. A - Loss of gloss: Initial setting can be detected clinically by
A. loss of gloss
B. the end of the exothermic reaction
C. a change in color
D. testing to see whether the material is hard enough to separate
from the impression6. C - anatomic portion: The area of the
diagnostic cast that records the hard and soft tissues is called the
A. art portion
B. base
C. anatomic portionD. impression
7. A - both statements are true: A study model is a positive
reproduction. An impression is a negative reproduction.
A. both statements are true
B. both statements are false
C. the first statement is true, the second statement is false
D. the first statement is false, the second statement is true
8. A - saliva: Material that will act as retarders for the set of
gypsum products include A. Saliva
B. Set gypsum products
C. slurry water from the model trimmer
D. non of the above are considered retarders
, 9. D. A and B: It is important to consider the following statements
when pouring an impression
A. alginate impressions should remain unseparated from the
model for only 1 hour B. when the single-step method is used, the
material poured into the impression must reach the initial set
before the base is poured
C. Gypsum should be mixed as wet as possible to allow for
sufficient working time D. A and B
E. A and C
10. A - patient education: Diagnostic casts are used for
A. patient education
B. fabricating dentures
C. fabricating crowns
D. fabricating orthodontic appliances
11. E - A and C: CAD/CAM fabrication of indirect restorations
eliminates the need for
A. investing
B. cutting the preparation
C. impression taking
D. A and B
E. A and C
12. B - the point at which the wax softens: The melting range
can best be described as
