Deck 47: Laboratory Materials and Procedures

Question 1

A custom impression tray should fit and adapt well to the model and should maintain ____ mm of impression material between itself and the teeth.

A)1 to 2
B)2 to 3
C)3 to 4
D)5 to 6

Answer 1

3 to 4

Question 2

Which type of baseplate wax is a softer and used for denture construction?

A)I
B)II
C)III

Answer 2

I

Question 3

Which type of dental wax is used to construct occlusal rims and set denture teeth in the wax-up?

A)Bite registration
B)Baseplate
C)Utility
D)Boxing

Answer 3

Baseplate

Question 4

Which of the following gypsum products has the highest powder-to-water ratio?

A)Model plaster
B)Dental stone
C)High-strength stone
D)All gypsum products have the same powder-to-water ratio.

Question 5

Which statement regarding infection control in the dental laboratory is accurate?

A)It is equally as important as when you are with a patient.
B)It is not as critical as when you are with a patient.
C)It is not a consideration because impressions are disinfected at chairside.
D)It depends on the patient's medical history.

Question 6

A model consists of the _____ portion,which represents the teeth and tissues of the mouth,and the _____ portion,which forms the base of the cast.

A)art; anatomical
B)anatomical; foundation
C)anatomical; art
D)oral cavity; foundation

Question 7

Which statement is incorrect regarding safety precautions in the laboratory?

A)PPE should be worn while working in the laboratory.
B)Manufacturer's instructions should be followed for equipment operation.
C)This is the appropriate place for eating and drinking in the dental office.
D)The work areas should be kept clean before and after procedures.

Question 8

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

A)pointed; rounded
B)rounded; pointed
C)rounded; rounded
D)pointed; pointed

Question 9

The ______ is the measurement of where the teeth are positioned when the joints are aligned correctly and before the teeth actually come together.

A)bite record
B)articulator
C)centric relation
D)Both a and c are correct.

Question 10

Which of the following is used to prevent a custom impression tray from sitting too deeply when taking the impression?

A)A spacer
B)Stops
C)Undercuts
D)All of the above

Question 11

Which of the following statements correctly describes the pouring methods used to create the base portion of a dental model?

A)The art portion of the cast is poured first when the double-pour method is used.
B)The completed box should extend at least 1 inch above the palatal area of the maxillary impression when the box-and-pour method is used.
C)The inverted-pour method consists of mixing one large mixture of plaster or stone and pouring both portions of the model in a single step.
D)The "box" used in the box-and-pour method is made of baseplate wax.

Question 12

Water should be running through a model trimmer:

A)when turned off.
B)when trimming.
C)after trimming.
D)before trimming.

Question 13

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

A)Overhead costs rise.
B)The dentist or private laboratory technician can handle larger cases.
C)More work will be completed by the commercial laboratory.
D)There is less work to do for the private dental laboratory technician.

Question 14

Which form of gypsum products is used for the creation of dies?

A)Plaster
B)Model plaster
C)Dental stone
D)High-strength stone

Question 15

What is the powder-to-water ratio for high-strength stone?

A)10
B)19
C)30
D)45

Question 16

Which methods are used to protect against biohazard contamination from impressions?

A)Disinfecting impressions in the treatment room before bringing them to the laboratory
B)Disinfecting laboratory benches and other contaminated items after use
C)Disinfecting laboratory benches and other contaminated items before use
D)All of the above

Question 17

When constructing ______ with a vacuum former,use a heavier-gauge,flexible plastic that does not require a spacer but does require an attachment for the strap.

A)an impression tray
B)provisional coverage
C)a vital bleaching tray
D)a mouth guard

Question 18

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

A)Stronger
B)Weaker
C)Unaffected
D)None of the above

Question 19

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

A)Sandblaster
B)Model trimmer
C)Vacuum former
D)Dental lathe

Question 20

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

A)Sticky
B)Inlay casting
C)Baseplate
D)Bite registration

Question 21

What causes air bubbles in a model?

A)Using a vibrator
B)Adding stone in small increments
C)Impression material that is too thick
D)Improper pouring of the impression

Question 22

Before constructing a light-cured tray,what would be painted on the model?

A)Adhesive
B)Plaster
C)Monomer
D)Separation medium

Question 23

In minutes,how long should one wait before removing a model from an impression after pouring?

A)10 to 15
B)15 to 30
C)30 to 45
D)45 to 60

Question 24

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

A)Face bow
B)Occlusal register
C)Bite block
D)Articulator

Question 25

How should a plaster mix not be manipulated?

A)Complete mix within 2 minutes.
B)Press bowl lightly on the vibrator.
C)Complete mix in 30 seconds.
D)Mix slowly until smooth.

Question 26

Which type of resin is formed into a diagnostic model using heat and a vacuum former?

A)Self-cured
B)Light-cured
C)Thermoplastic
D)Auto-cured

Question 27

The first step in making a custom tray is to:

A)prepare the resin.
B)make a spacer.
C)prepare a diagnostic model.
D)place blockout material.

Question 28

Light-cured resin can be used to make trays for which type impressions?

A)Edentulous
B)Dentulous
C)Partially edentulous
D)All types

Question 29

When taking a face-bow registration,the vertical indicator rod should be aligned with which oral landmark?

A)Midline
B)Upper first molar
C)Lower canine
D)Nose

Question 30

Which technique listed would be incorrect when pour an impression?

A)In small increments
B)In large amounts
C)In the same place
D)In a continuous flow

Question 31

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

A)After the heat has dissipated
B)While it is giving off heat
C)Immediately after construction
D)After 24 hours

Question 32

What should be done to an impression before pouring?

A)Dry the impression completely with a blast of air.
B)Use a gentle stream of air to remove excess moisture.
C)Have the impression saturated with moisture.
D)Leave disinfecting solution in the impression.

Question 33

How should the patient bite when positioning the bite-fork during a face-bow registration?

A)Quickly
B)Firmly
C)Slowly
D)Slide

Question 34

When would a light gauge,vacuum-formed resin material be used?

A)Bleaching trays
B)Provisional coverage
C)Impression tray
D)Both a and b

Question 35

When constructing custom trays it is best to remove excess material with a lab knife after it has cured.

Question 36

How should light-cured resin tray material be cured?

A)For 10 minutes
B)Off the model
C)For 2 minutes
D)Without the spacer