The primary goal of infection control when handling and disinfecting impressions, dentures, and appliances is to:
D. prevent cross contamination
The term used for the setting of hydrocolloid impression materials is:
FILL IN
(T/F) Direct restorative materials are fabricated in the dental lab.
False
Air incorporated into a gypsum mix results in:
Surface inaccuracies
Why is a dental stone vibrated after mixing?
B. the vibration makes the mixture more dense by removing any trapped air pockets
The Brinell and Knoop tests are used in determining:
Hardness
Model plaster is:
A. type II gypsum
What is another name for a dental material's stiffness?
Modulous of elasticity
For most dental materials that include water in the composition, the onset of setting is signified by:
C. loss of gloss
When an agar impression slightly contracts and exudes water, it is termed:
D. syneresis
Which of the following materials undergoes imbibition?
B. alginate impression material
Immediately after an impression is taken, it must be rinsed under running water to remove saliva or blood. This step is essential before the impression can be disinfected.
Both statements are true.
Agar-agar transforms from a fluid paste to a rubber like solution by a (blank) process.
a. chemical
b. physical
b. physical
Which of the following is NOT a flexible impression material?
A. ZOE
An increase in the temperature of the water used in mixing irreversible hydrocolloids will:
shorten time to set
The chief difference between model plaster powder and dental stone powder is:
D. particle size and shape
Coefficient of thermal expansion is:
A. measurement of change in volume in relation to change in temperature
Which of these non-aqueous impression materials is most commonly used today?
a. polysulfide rubber
b. silicon rubber
c. polyether rubber
d. polyvinyl siloxane
d. polyvinyl siloxane
What is the chemical composition of set gypsum products?
D. calcium sulfate dihydrate
(T/F) A liquid with high viscosity has a good wetting ability.
False.
(T/F) Another name for a dental bridge is a fixed partial denture.
True
Glass ionomers are popular because they:
D. all of the above
(T/F) When fabricating ceramic restorations, sintering changes the porcelain powder into a solid.
True
(T/F) Non-precious alloys with high melting temperatures are nickel and silver.
False
(T/F) When classifying casting alloys according to the ADA, the differences are predominantly strength and elongation.
True
(T/F) An abutment (retainer) is the portion of a fixed bridge that replaces the missing tooth.
False
(T/F) Precious metals are classified based on cost.
True
One disadvantage of dental porcelain restorations is:
D. brittleness
The difference between an inlay and an onlay is that:
C. an inlay should not exceed one-half the intercuspal distance, while an onlay covers the cusps
Which of the following is true concerning the first application of dental porcelain to a porcelain fused to metal crown?
A. the first layer is called "opaque" and effectively covers the metallic sheen of the underlying casting
The casting process requires:
D. a, b, and c only
Which of the following groups of metallic elements would be called precious or noble for their ability to resist corrosion?
D. gold, silver, and platinum
Which of the following is a disadvantage of using a gold alloy for indirect restorations?
C. lack of esthetic qualities
The purpose of a temporary crown is:
D. all of the above
Which of the following materials is not used for indirect restorations?
C. amalgam alloys
An alloy that is 50% gold by weight is what caratage?
D. 12
In casting a restoration for a patient, the proper sequence of events is:
A. wax, invest, burn out, cast, polish
An alloy that is 25% gold by weight is what caratage?
D. 6 carat
Another name for a 3 unit dental bridge with two consecutive abutments and a pontic is (abutment #28, abutment #29, pontic #30):
D. cantilever bridge
An indirect restoration used when a cusp is in need of replacement but a full crown is not indicated is a/an:
C. only
What population(s) benefit from the ART technique?
E. all choices are correct
An example of an indirect restorative material is:
B. gold inlay
Originally in dentistry, what did ART stand for?
C. Atraumatic Restorative Technique
What is/are the benefit(s) of the ART technique?
A. all answers are correct
Newer types of composite materials are radiographically easier to distinguished from older type composites due to the fact that the newer composite materials:
B. contain radiopaque filler particles
The size of the filler particles in a dental composite determines the:
C. surface smoothness of the resulting restoration
The specific amount of composite (thickness) that us cured by a light source is termed:
D. depth of cure
Which type of abrasive looks like a grayish-black sand and sometimes called "corundum"?
C. Emery
Which type of abrasive is produced from volcanoes and is used in the laboratory to finish acrylic denture bases and on restorative materials, such as gold, amalgam, and gold foil?
d. pumice
g. aluminum oxide
h. sand
B. pumice
Which abrasive is also known as calcium carbonate?
D. Whiting
Which of the following factors affect the rate of abrasion?
J. a, b, c, and d only
(T/F) Carbon steel burs are made by packing powdered metal pieces into a mold and then sintering. They are harder than tungsten carbide burs and retain a sharper cutting edge longer than those made of tungsten carbide.
False
(T/F) The process of producing the final shape and contour of a restoration is called cutting.
False
APF (acidulated phosphate fluoride) is not recommended for the following dental materials:
A. glass ionomer, composites, and porcelain
The margins of a cast restorations can be altered by instrumentation with curettes, scalers, and explorers. A suggested technique for deposit removal in these areas is to use:
D. an oblique or horizontal stroke, with appropriate instruments
What are the polishing agents of choice for polishing a gold crown intraorally?
I. d and e only
Tarnish is:
D. caused by a corrosive attack that produces a film or surface later on a metal and may protect the metal and prevent corrosion
Which of the following sterilizers is the most effective for destroying pathogenic organisms or vegetative forms?
A. steal autoclave
The main components of stainless steel alloy are:
A. chromium, iron, and nickel
The standard protocol for stream autoclaving (not rapid steam heat) is:
B. 270 degrees F and 27 psi for at least 15 minutes
(T/F) Electropolishing is a chemical process that creates a thin layer of chromium oxide on the surface of an instrument, thus protecting that metal from corroding.
False
A successfully etched enamel surface has a (blank) appearance.
A. frosty, chalky white
In sealant placement, etching functions to do which of the following?
B. produce micropores in the enamel surface
The major factor in the failure of a pit and fissure sealant is:
A. salivary contamination of the etched surface
The expected life of a sealant is:
C. three to five years
When mixing cements, the powder to liquid ratio depends on the:
C. a and b
Zinc oxide eugenol cement is used for a:
D. b and c
To protect the pulp in a tooth with a tiny pulp exposure, which of the following materials is mixed and placed in the cavity preparation first?
D. calcium hydroxide
Which of the following statements is false regarding bases and liners?
A. a liner provides good thermal insulation
Which of the following is NOT indicated for final cementation for luting of indirect restorations?
A. calcium hydroxide cement
Glass ionomers are popular because they:
D. all of the above
Cement liners are:
A. used to protect the pulp from chemical irritation
What solution should be used to clean the ZOE and other dental cements?
B. orange solvent
Zinc phosphate may be used as a:
1. luting agent for permanent cementation of a full gold crown
2. high strength base under a restoration
3. cavity liner
4. temporary restoration
C. 1 and 2
Dental cements are used for:
D. all of the above
When used as a base, zinc phosphate's greatest physical characteristics is its:
D. compressive strength
A glass slab should be cooled when mixing zinc phosphate cement to:
A. increase the powder-liquid ratio
Which of the following dental materials promotes the formation of secondary dentin?
D. calcium hydroxide cement
The liquid component of polycarboxylate cement is:
B. polyacrylic acid
Which one of the following cements will produce an exothermic reaction upon mixing?
E. zinc phosphate cement
(T/F) Glass ionomer cements are the strongest and least soluble of dental cements.
True
(T/F) Glass ionomers can be used as a luting agent only.
False
A bite registration is used to record a patient's bite pattern. It is also used to position upper and lower casts in the same relationship as the supporting tissue.
Both statements are true
Tissue conditions are temporary materials because they:
D. deteriorate quickly
The activator in the liquid component of the materials necessary to fabricate a denture is a tertiary amine. This activator is only present in cold cure components.
Both statements are true.
Which of the following should not be used to clean a cast partial denture?
C. bleach
Most denture teeth used today are acrylic rather than porcelain. Porcelain teeth are softer than acrylic teeth and do not cause excessive wear on natural opposing teeth.
The first statement is true; the second statement is false.
The principle advantage of ZOE cement over zinc phosphate cement is its:
D. obtundant effect on the pulp
Mandibular dentures are easier to wear than maxillary. Saliva helps to improve the suction needed to hold a denture in place.
Both statements are true
Heat activated acrylic resin systems are very similar to chemically activated systems. The major difference (or exception) is:
A. heat activated systems have much less strength than chemically activated systems
To repair a broken denture, a thin layer is ground off. Next, monomer is applied to the surfaces so that:
B. the finishing and polishing of the repair is made easier
(T/F) Cold cure denture relines are just as strong as lab relined dentures.
