Ch 47

Question 1

Speciality Practices?

Answer 1

orthodontics, pediatric, and prosthodontics

Question 2

biohazards

Answer 2

items bought into the lab the can harbor infective blood and saliva

Question 3

infective blood and saliva are?

Answer 3

biohazards

Question 4

MSDS

Answer 4

material safety data sheet

Question 5

study cast/models/diagnostic cast

Answer 5

3d reproductions of the teeth and soft tissue of patients max and many. arches

Question 6

a mineral mined from earth

Answer 6

gypsum

Question 7

dihydrate

Answer 7

gypsum in its unrefined state

Question 8

gypsum in powdered state

Answer 8

hemihydrate

Question 9

What does the dihydrate form of calcium sulfate mean?

Answer 9

It means that it consists of two parts water to every one part calcium sulfate

Question 10

What does the hemihydrate form of calcium sulfate mean?

Answer 10

It means only one-half part water to one part calcium sulfate.

Question 11

materials used to make dental models

Answer 11

gypsum

Question 12

types of gypsum

Answer 12

model plaster
____________
highstrength stone

Question 13

types of gypsum

Answer 13

highstrength stone
dental stone
_________

Question 14

When you mix gypsum powder with water….

Answer 14

the hemihydrate crystals dissolve in water to form clusters known as the nuclei of crystallization

Question 15

Nuclei of crystallization

Answer 15

hemihydrate crystals dissolved in water

Question 16

What occurs with more intermeshing of the gypsum crystals

Answer 16

The more meshing that occurs, the greater the strength, rigidity, and hardness of the final product

Question 17

As the gypsum crystals grow during the setting process

Answer 17

they intermesh and become entangled with each other

Question 18

all 3 forms of gypsum consist of….

Answer 18

hemihydrate crystals

Question 19

Which form of gypsum has the densest crystals?

Answer 19

High-strength stone

Question 20

Which form of gypsum requires the most water for mixing

Answer 20

Model plaster

Question 21

differences of gypsums

Answer 21

size, shape, porosity of hemihydrate crystals

Question 22

dental plaster aka

Answer 22

plaster of paris

Question 23

dental plaster

Answer 23

white in color

Question 24

what is used to pouring impressions to make diagnostic models

Answer 24

dental plaster

Question 25

the crystals in ___ are irregular in shape and porous

Answer 25

plaster

Question 26

Model plaster requires the greatest quantity of water for mixing

Answer 26

which produces the weakest of the three forms of study model

Question 27

yellow in color

Answer 27

stone

Question 28

stone is used for a ....

Answer 28

more durable diagnostic cast is required

Question 29

dental stone crystals are.....

Answer 29

uniform in shape and less porous

Question 30

stone is .....

Answer 30

strong and denser

Question 31

Although stone is uniform and less porous it is....

Answer 31

less uniform in shape and more porous than those found in high-strength stone.

Question 32

High strength stone aka

Answer 32

densite or improved dental stone

Question 33

High strength stone has.......

Answer 33

the strength, hardness, and dimensional accuracy that make it ideal for use by the dental laboratory technician

Question 34

crystals in high strength stone are...

Answer 34

smooth, dense, and require less water for mixing

Question 35

which gypsum is used mostly for dental lab techs?

Answer 35

high strength stone

Question 36

which gypsum is ideal for dental lab techs bc of its strength, hardness, and dimensional accuracy?

Answer 36

high strength stone

Question 37

die is used for....

Answer 37

making wax patterns for crowns, bridges, and indirect restorations

Question 38

plaster powder/water ratio

Answer 38

100 g) to 45 to 50 mL of water

Question 39

dental stone p/w ratio

Answer 39

100 g) to 30 to 32 mL of water

Question 40

high strength stone p/w ratio

Answer 40

(100 g) to 19 to 24 mL of water

Question 41

when too little water is used....

Answer 41

it will be difficult to mix and shorter working time

Question 42

too much water...

Answer 42

mix will be thing and runny and longer setting time. the model will be weaker

Question 43

add all powder to water at same time or...

Answer 43

the crystallization process will be disturbed and the model will be weak