Deck 39: Laboratory Materials and Techniques

Question 1

When making a custom acrylic crown, a matrix of some type must be used.

Answer 1

True

Question 2

The most common use for alginate is ____________.

A) impressions for crown and bridges
B) occlusal registrations
C) impressions for study models
D) final impressions for a full denture

Answer 2

impressions for study models

Question 3

The ideal temperature for mixing alginate is ____ degrees F.

A) 32
B) 50
C) 70
D) There is no ideal temperature.

Answer 3

70

Question 4

Diagnostic casts can be trimmed in a geometric form that is pleasing in appearance.

Question 5

Alginate in the gel state is ____________.

A) liquid
B) solid
C) gas
D) alginate does not go into the sol state

Question 6

Alginate in the sol state is ____________.

A) liquid
B) solid
C) gas
D) alginate does not go into the sol state

Question 7

Temporary restoration and provisional restoration are the same.

Question 8

Silicone impression materials have all the advantages of polysulfides without the disadvantages.

Question 9

Silicone-based impression materials are an alternative to alginate materials.

Question 10

A regular stock tray for taking impressions will fit all patients' mouths.

Question 11

It is very unlikely for cross-contamination of impression materials to occur between the treatment room and the laboratory.

Question 12

It is advised to take the maxillary alginate impression first to get the more difficult impression for the patient over with.

Question 13

Impressions are a negative mold of the tooth.

Question 14

An articulator is used to duplicate the patient's occlusion on models.

Question 15

Syneresis of an impression occurs when ____________.

A) additional water is taken in
B) water is lost
C) the impression is left to soak in water
D) none of the above

Question 16

Undercuts are ____________.

A) areas that have been overprepped by the handpiece
B) areas that have been underprepped by the handpiece
C) recessed areas that are wider on bottom than on the top
D) none of the above

Question 17

One of the first impression materials that has good detail is reversible hydrocolloid impression material.

Question 18

The most convenient way to alter the setting time for alginate is to ____________.

A) add less or more water
B) add less or more powder
C) adjust the water temperature
D) The setting time should never be altered.

Question 19

A facebow and an articulator are used to duplicate the function of the temporomandibular joint.

Question 20

The margins of a temporary crown must fit snugly and accurately along the prepared margin of the tooth.

Question 21

Heating the raw gypsum in the manufacturing process is known as ____________.

A) mining
B) agitating
C) calcination
D) none of the above

Question 22

The tray used for alginate impressions is (are) ____________.

A) perforated
B) rim locked
C) either a or b
D) neither a nor b

Question 23

The ratio of water to powder for model plaster is ____ ml to 100 g.

A) 24
B) 30
C) 50
D) 60

Question 24

When taking an alginate impression, which area is seated first?

A) Anterior
B) Posterior
C) The tray is seated straight downward.
D) It does not matter which area is seated first.

Question 25

The removal of the alginate impression is done ____________.

A) slowly
B) with a twisting motion
C) with a rocking motion
D) with a quick snap

Question 26

The process of placing wax around the borders of the tray is ____________.

A) beading
B) waxing
C) addition
D) luting

Question 27

The shelf life of alginate material is approximately ____________.

A) 1 week
B) 1 month
C) 1 year
D) indefinite

Question 28

Polyether is supplied in ____________.

A) powder or liquid form
B) two-paste form
C) single light-cured paste form
D) putty or wash form

Question 29

Another name for polysulfide impression material is ____________.

A) rubber base
B) silicone
C) either a or b
D) neither a nor b

Question 30

The ratio of water to powder for stone is ____ ml to 100 g.

A) 24
B) 30
C) 50
D) 60

Question 31

The putty material in silicone impression materials is ____________.

A) placed in the syringe
B) mixed as it is dispensed in the extruder gun
C) placed in the tray
D) none of the above

Question 32

During the process of setting up gypsum, heat is given off, causing a(n) ____________.

A) calcining process
B) transformation process
C) either a or b
D) exothermic reaction

Question 33

Both alginate and agar-agar are derived from ____________.

A) limestone
B) seaweed
C) gelatin
D) clay

Question 34

When recording an occlusal registration, the wax is softened with ____________.

A) a flame and placed on the patient's maxillary arch
B) a flame and placed on the patient's mandibular arch
C) warm water and placed on the patient's maxillary arch
D) warm water and placed on the patient's mandibular arch

Question 35

The final set of plaster is ____________.

A) 15 minutes
B) 30 minutes
C) 1 hour
D) 24 hours

Question 36

The warmer the water used in mixing a gypsum product, the __________ the material will set.

A) faster
B) slower
C) firmer
D) softer

Question 37

Agar-agar is tempered for ____ minutes before placing it in the patient's mouth.

A) 5
B) 10
C) 20
D) Tempering is not necessary.

Question 38

When loading the maxillary tray with alginate, the material is loaded in ____________.

A) several increments
B) one increment from the posterior
C) several increments from the lingual and posterior
D) two increments from the lingual

Question 39

When loading the mandibular tray with alginate, the material is loaded in ____________.

A) several increments
B) one increment from the posterior
C) several increments from the lingual and posterior
D) two increments from the lingual

Question 40

Reversible hydrocolloid is maintained in the sol state if placed in a water storage bath of ____ degrees F.

A) 212
B) 150
C) 110
D) 55

Question 41

After a self-curing acrylic tray has been made, it should be allowed to set for ____________.

A) 10 minutes
B) 1 hour
C) 24 hours
D) it does not need to set

Question 42

Adjusting the height of an aluminum temporary crown is done by ____________.

A) trimming the gingival margin
B) using an acrylic bur on the occlusal of the temporary crown
C) selecting a short temporary crown
D) the height cannot be adjusted

Question 43

Custom trays are (can) be made from ____________.

A) thermoplastic material
B) vacuum resin
C) acrylic resin
D) all of the above

Question 44

Polymerization is the same as ____________.

A) curing
B) mixing
C) trimming
D) trying on in the patient's mouth

Question 45

When maxillary and mandibular models are trimmed and in occlusion, the overall height should be ____ inches.

A) 1.5
B) 2
C) 3
D) It does not matter.

Question 46

Which classification is inlay wax?

A) Pattern
B) Processing
C) Impression
D) Study

Question 47

Type III gypsum is used for ____________.

A) study models
B) working models
C) dies
D) mounting casts on an articulator

Question 48

Before trimming plaster models, dry models should be soaked in water for ____________.

A) 2 minutes
B) 5 minutes
C) 10 minutes
D) 24 hours

Question 49

Which classification is undercut wax?

A) Pattern
B) Processing
C) Impression
D) Study

Question 50

Before cementing any temporary crown, a final check must be done for ____________.

A) marginal fit
B) contour
C) occlusion
D) all of the above

Question 51

The size of a preformed crown is determined by the ____________.

A) height of the crown
B) facial and lingual measurement
C) mesial and distal measurement
D) tooth in the dentition

Question 52

Which of the following gypsum products is the weakest?

A) Plaster
B) Lab stone
C) Orthodontic stone
D) Die stone

Question 53

Which classification is utility wax?

A) Pattern
B) Processing
C) Impression
D) Study

Question 54

In a self-curing acrylic tray resin, the monomer is a ____________.

A) liquid catalyst
B) powder
C) plasticizer
D) softening agent

Question 55

What is placed on the model during construction to allow room in the tray for the impression material?

A) Stops
B) Spacer
C) Handle
D) None of the above

Question 56

When pouring an impression, place a ____________.

A) small amount to touch the midline area of the impression
B) small amount to touch the most distal surface of one side of the impression
C) large amount to touch the most distal surface of one side of the impression
D) it does not matter how much or where the gypsum is placed

Question 57

When a material becomes soft and pliable during exposure to heat, it is ____________.

A) thermoset
B) wax
C) thermoplastic
D) none of the above

Question 58

Which classification is boxing wax?

A) Pattern
B) Processing
C) Impression
D) Study

Question 59

The biggest advantage of light-cured temporary material is that it ____________.

A) is less expensive
B) has a reduced working time
C) is available in the shades of enamel
D) has an unlimited setting time

Question 60

It is desirable for bases to be ____________ the art portion of a model.

A) weaker than
B) thicker than
C) the same as
D) none of the above

Question 61

The referred name of agar-agar is relevant to which impression material?

A) Alginate
B) Hydrocolloid
C) Polysiloxane
D) Polysulfide

Question 64

_________ of the trimmed model is made from the anatomic portion of the cast.

A) One-half
B) One inch
C) Two-thirds
D) Two inches

Question 65

Each portion of the trimmed diagnostic cast is trimmed to ____ inch of anatomic portion.

A) 1/2
B) 1
C) 2
D) 1.5

Question 66

Trimmed diagnostic models should exhibit ____ -inch base each.

A) 1/2
B) 1
C) 2
D) 2.5

Question 67

____________ is a dimensional change in shape.

A) Calcination
B) Gel
C) Sol
D) Distortion