Dental Assisting Final (Ch. 43-64 Multiple Choice)
The size of the wax spatula most commonly used in the laboratory is a
#7
The powder (g)/water (ml) ratio of plaster for pouring a dental model is
100/50
The powder/water ratio for maxillary preliminary impression is
3 scoops of powder to 3 measure of water
How long should you wait before you separate a model from its impression?
45 to 60 minutes
Of the three types of custom trays discussed in the chapter, which technique uses a volatile hazardous material?
Acrylic resin
Which material would be selected for the fabrication of provisional coverage?
Acrylic resin
When a gypsum material is mixed, how is the powder and water incorporated?
Add powder to the water
Irreversible hydrocolloid material is also referred to as
Alginate
Which of the following terms is a description of a certain portion of a dental model?
Anatomic, Art
What is the one specific area of a dental model where the maxillary and mandibular models are trimmed differently?
Anterior portion
Elastomeric materials are intended for what type of impression?
Final
Which specialty practice might have a more extensive laboratory setup?
Fixed prosthodontics, Orthodontics
What type of tray is most commonly selected when zinc oxide-eugenol bite registration material is used?
Gauze
At the completion of the process for mixing polycarboxylate cement, the end product should appear
Glossy
The three noble metals used in making indirect restorations are
Gold, palladium, and platinum
What dental material is used in the creation of a dental model?
Gypsum
Which type of gypsum is used to fabricate a die for making an indirect restoration?
High-strength stone
Which variable can affect the addition or loss of water in a material?
Humidity
What temporary restorative material would be selected for a Class II cavity preparation?
IRM
An example of a contaminated item that could be found in the dental lab would be a(n)
Impression
What is used to triturate capsulated dental materials?
In an air-tight container
Where are amalgam scraps disposed of?
In an air-tight container
Where would you commonly find the lab in a dental office?
In proximity to the clinical operatory
How is self-cured acrylic resin supplied for the fabrication of custom trays?
Powder and liquid
Of the three classification of impressions, which of these could be an expanded function for the certified dental assistant?
Preliminary, Final
The purpose of a dental liner is to
Protect the pulp from any type of irritation
For which of the following procedures would you include a temporary cement on the tray setup?
Provisional coverage
A base is placed in or on the ______________ in a cavity preparation
Pulpal floor
Which type of stock tray would be selected and prepared to cover half of an arch?
Quadrant
While the dentist is dispensing the syringe material around the prepared tooth, what should the dental assistant be doing during a final impression procedure?
Readying the tray with heavy-body material
Why would you select a fast-set alginate when taking a preliminary impression?
The patient has a strong gag refelx
What type of custom tray would be made for a vital bleaching procedure?
Thermoplastic resin
On what type of mixing pad is ZOE mixed?
Treated paper pad
Temp bond is supplied as
Two tubes of paste
What type of zinc oxide-eugenol (ZOE) is used for permanent cementation?
Type II
How do you dissipate the heat from zinc phosphate in the mixing process?
Use a cool glass slab
The final step in finishing a composite resin is
Use of a rubber cup and polishing paste
_______________ would be used to extend the length of a tray to accommodate third molars.
Utility wax
Which supplemental material is contraindicated under composite resins and glass ionomer restorations?
Varnish
Baseplate wax is _______________ before being placed in the patient's mouth for a bite registration
Warmed
Hydro- means
Water
What should be placed between the two models during trimming?
Wax bite
Which type of tray is constructed to fit the mouth of a specific patient?
Custom
How is the light-body impression material applied during the final impression procedure?
Extruder with tip
Which piece of lab equipment would the dentist use to determine centric relation from a diagnostic model?
Face bow
Which professional organization evaluates a new dental material?
ADA
The term commonly used to refer to dimethacrylate is
BIS-GMA
What type of wax is used to obtain a patient's bite?
Baseplate wax
__________________ is the material universally used for taking a bite registration
Baseplate wax
Of the three classification of impressions, which would be used by the dental lab tech for determining occlusal relationship?
Bite registration
The purpose of a dental bonding material is to
Bond restorative materials to the tooth structure
What type of wax is used to form a barrier around a preliminary impression when it is poured up?
Boxing wax
How does an auto-cured material harden or set?
By chemical reaction
What unique ingredient in the powder of glass ionomer cement helps inhibit recurrent decay?
Calcium
Another term for decay is
Cavity
What type of reaction does a dental material undergo when a person is chewing?
Compressive stress
What dental instrument is selected to press a base into the cavity preparation?
Condenser
Where would reversible hydrocolloid material be placed prior to taking the impression?
Conditioning bath
What happens to a dental material when it is exposed to extreme temperatures of hot and then cold?
Contraction and expansion
Another name for a dental model is
Dental cast
Calcium hydroxide is placed on what tooth structure?
Dentin
What does the dentin sealer seal?
Dentin tubules
In light-curing of composite resins, which factor can affect curing time of the material?
Depth or extent of restoration
Why is dental amalgam not placed in anterior teeth?
Esthetics
What type of restoration is always made in a dental laboratory setting?
Indirect restoration
Which viscosity of a final impression material is applied first to the prepared tooth or teeth?
Light body
Which sequence is recommended for the application of supplementary materials for a deep restoration?
Liner, base, dentin, sealer, bonding system
Which filler type of composite resin has the strongest makeup and has been used most commonly for posterior restorations?
Macrofilled
Which model (maxillary or mandibular) should you begin trimming first?
Maxillary
On or in what is irreversible hydrocolloid material mixed?
Mixing pad
Which piece of lab equipment would be used to grind away plaster or stone?
Model trimmer
When pouring-up impression, where would you begin placing the gypsum material in a mandibular impression?
Most posterior teeth
An impression would be considered a
Negative reproduction
Restorative dentistry is often referred to as
Operative dentistry
______________________ is/are (an) example(s) of an enamel bonding procedure
Orthodontic brackets, Sealants
How is a elastomeric material supplied?
Paste, Cartridge, Putty
Which type of impression tray allows the impression material to mechanically lock on?
Perforated
The main component in the liquid of zinc phosphate is
Phosphoric acid
Which statement is not one of calcium hydroxide's characteristics?
Replaces the need for a dentin sealer
A preliminary impression is _____________ before being transported to the lab for pouring up.
Rinsed, disinfected, wrapped in a moist paper towel, and placed in a precautionary bag
To extend an impression tray, what type of wax is used?
Rope utility wax
Another name for polysulfide is
Rubber base
Which is an example of how galvanic action can occur?
Salt within saliva, Touching of two metals
The organic substance of hydrocolloid material is
Seaweed
What is used to determine the color of composite resin material for a procedure?
Shade guide
Select the correct makeup of the alloy powder in amalgam
Silver, tin, copper, and zinc
If the powder of a dental material is dispersed in increments, what size increment is commonly brought into the liquid first?
Smallest
What is removed from tooth structure before a bonding material is placed on dentin?
Smear layer
What effect does eugenol have on the pulp?
Soothing
What can be placed to prevent a tray from seating too deeply onto the arch or quadrant?
Spacer stops
What additional method can be used to mix final impression material instead of using an extruder?
Spatula and pad
Most amalgams have a high copper content. What does copper provide to amalgam restorations?
Strength, Corrosion resistance
How is the liquid portion of polycarboxylate cement supplied?
Supplied
Can a glass ionomer material be used as a restorative material?
Yes
Can a resin cement be used with a metal casting?
Yes
Another name for dentin sealer is
desensitizer
The acronym IRM stands for
intermediate restorative material
Another name used to describe permanent cement is
luting agent
An insulating base is placed to
protect the pulp from thermal shock
The key ingredient in varnish is
resin