Quiz 2

Question 2

Which type of wax is preformed with a thin sheet of aluminum foil between the layers?

Answer 2

Bite wafers

Bite wafers are another example of bite registration wax.

Question 3

Which material should be used if a more durable impression material is needed for bite registration?

Answer 3

Zinc oxide–eugenol (ZOE)

ZOE has no resistance to bite closure.

Question 4

How does an Automix mixing unit system aid in infection control?

Answer 4

Less time is spent cleaning and disinfecting guns and cartridges.

Question 5

Which item is used to polish or trim custom trays, provisional coverage, dentures, and indirect restorations?

Answer 5

Dental lathe

Question 6

How will a water temperature of 80° F (26.6° C) affect an alginate mix?

Answer 6

It will make the mix set faster.

Question 7

What are the three classifications of impressions used in dentistry?

Answer 7

Preliminary, final, and occlusal, or bite registration

Question 8

Which type of baseplate wax is softest?

Answer 8

Type I

Question 9

What are preliminary impressions used to make?

Answer 9

Diagnostic models

Also used for provisional coverage and orthodontic appliances.

Question 10

Which type of impression tray covers the anterior portion of the dental arch?

Answer 10

Section

Question 11

After fabrication, when can a self-cured resin custom tray be used?

Answer 11

After the heat has dissipated

Question 12

Why would a dentist request preliminary impressions?

Answer 12

To fabricate custom trays

Also used for diagnostic models and provisional coverage.

Question 13

What causes air bubbles in a model?

Answer 13

Improper pouring of the impression

Question 14

Alginate impressions must be poured within _____ so that distortion does not occur.

Answer 14

1 hour

Question 15

How will gypsum material be affected if additional powder is added after mixing has begun?

Answer 15

Weaker

Question 16

How are alginate impressions removed from the mouth?

Answer 16

Use one quick, snap-out motion.

Question 17

What are the three curing stages of impression materials?

Answer 17

Initial set, final set, final cure

Question 18

Which portion of the maxillary impression tray should be seated in the mouth first?

Answer 18

Posterior

Question 19

Each of the following can be done to alleviate the gag reflex when taking alginate impressions except one. Which one is the EXCEPTION?

Answer 19

Have the patient sit upright with the head tilted backward.

Question 20

Which type of dental wax is often used to form a wall or box around a preliminary impression when it is poured up?

Answer 20

Boxing wax

Question 21

Which statement is correct regarding custom impression trays?

Answer 21

They can be constructed from resin.

Question 22

A trimmed maxillary model will be _____ at the anterior portion, and the mandibular model will be _____ at the anterior portion.

Answer 22

pointed; rounded

Question 23

How should alginate material be loaded into a maxillary impression tray?

Answer 23

Heavier in the anterior and labial areas

Question 24

The shelf life of alginate material is approximately __ months.

Answer 24

12

Question 25

What should be done to an impression before pouring?

Answer 25

Use a gentle stream of air to remove excess moisture.

Question 26

Where should alginate and elastomer impressions be disinfected?

Answer 26

Before leaving the treatment area

Question 27

What are advantages of the Automix system for elastomeric impression materials?

Answer 27

Homogenous mix of material without waste

Question 28

Which irreversible hydrocolloid material is used most widely for preliminary impressions?

Answer 28

Alginate

Question 29

What is the working time of normal-set alginate impression material?

Answer 29

2 minutes

Question 30

Which technique listed would be incorrect when pouring an impression?

Answer 30

In large amounts

Question 31

What is one advantage of having laboratory equipment and trained personnel in the dental office?

Answer 31

The dentist or private laboratory technician can handle larger cases.

Question 32

Which of the following is an acceptable method for altering the setting time of alginate irreversible hydrocolloid impression material?

Answer 32

Change the water temperature.

Question 33

What is an acceptable method for altering the setting time of alginate irreversible hydrocolloid impression material?

Answer 33

Change the water temperature. ## Footnote Cooler water increases the setting time, while warmer water shortens it.

Question 34

Which impression material is used when an extremely accurate final impression is essential?

Answer 34

Elastomeric. ## Footnote Elastomeric materials have a rubbery quality that allows for distortion-free removal.

Question 35

When should water be running through a model trimmer?

Answer 35

When trimming. ## Footnote Water should be turned off when the model trimmer is not in operation.

Question 36

Which type of reversible hydrocolloid material is the most viscous?

Answer 36

Tray. ## Footnote Syringe material is the least viscous, while tray material is the most viscous.

Question 37

How should a plaster mix not be manipulated?

Answer 37

Complete mix in 30 seconds. ## Footnote A proper mix should be completed in 2 minutes and mixed slowly until smooth.

Question 38

How is an alginate impression disinfected?

Answer 38

Spray the alginate with an intermediate-level disinfectant. ## Footnote Other methods can cause dimensional changes or are ineffective.

Question 39

Legally, who can take final impressions?

Answer 39

Dentist. ## Footnote Final impressions are essential for fabricating restorations and must be taken by a licensed dentist.

Question 40

What is an incorrect statement regarding safety precautions in the laboratory?

Answer 40

This is the appropriate place for eating and drinking in the dental office. ## Footnote No eating or drinking is permitted in the laboratory area.

Question 41

What does the term syneresis mean as it relates to alginate impression?

Answer 41

Water evaporates from the impression. ## Footnote This process causes the impression to shrink.

Question 42

What device holds maxillary and mandibular models in an occlusal relationship?

Answer 42

Articulator. ## Footnote The articulator helps maintain the correct occlusal relationship during model work.