Deck 8: Dental Ceramics

Question 1

The main advantage of the combination of porcelain and metal for fixed crown and bridge prosthodontics is:

A) superior esthetics when contrasted with all-porcelain jacket crowns
B) the strength and durability given to the restoration by the bond between a metal internal core and the esthetic external porcelain covering
C) direct fabrication of the restoration in the patient's mouth
D) the use of high-fusing porcelain for superior bonding to tooth structure

Answer 1

the strength and durability given to the restoration by the bond between a metal internal core and the esthetic external porcelain covering

Question 2

All-ceramic crowns have a more life-like appearance than porcelain-bonded-to-metal crowns because they:

A) have an opaque layer
B) do not have an opaque layer to hide metal
C) are cemented with different cements than porcelain-bonded-to-metal crowns
D) utilize high-fusing rather than low-fusing porcelain

Answer 2

do not have an opaque layer to hide metal

Question 3

Which of the following materials would not be used in today's porcelain formula?

A) Mostly glass
B) Feldspar
C) Particle-filled glass
D) Polycrystalline

Answer 3

Feldspar

Question 4

An extra light bleached tooth will have ____ chroma and ______ value.

A) high; high
B) high; low
C) low; high
D) low; low

Question 5

Which of the following methods for fabrication of ceramic restorations utilizes the lost wax technique similar to that used to cast gold crowns?

A) Slip-casting
B) Heat-pressing
C) Sintering
D) Computer-assisted machining

Question 6

____________ is the amount or intensity of the color present.

A) Hue
B) Value
C) Chroma
D) Metamerism

Question 7

Which of the following is true of computer-assisted machining for crown and bridge techniques?

A) Ceramic powder is mixed with a water-based liquid to form a mass that is pressed onto a porous refractory die.
B) No die needs to be poured and no temporary crown is needed.
C) A porous ceramic core is infiltrated with molten glass by capillary action.
D) It is available only for fabrication of porcelain veneers.

Question 8

The best arrangement for the coefficient of thermal expansion of the porcelain and the metal to be compatible is for the porcelain to have ________ thermal expansion than the metal.

A) significantly more
B) slightly more
C) slightly less
D) significantly less

Question 9

In general, the shade of a tooth should be taken _______ preparation of the tooth and ________ a rubber dam is placed.

A) before; before
B) before; after
C) after; before
D) after; after

Question 10

The metal in the area of a porcelain-fused-to-metal crown where the porcelain is to be bonded is approximately _______ mm thick.

A) 0.01 to 0.03
B) 0.1 to 0.3
C) 0.3 to 0.5
D) 1.0 to 2.0

Question 11

Silane is a coupling agent that may be added to the ________________ surface to enhance the bond and form a chemical union between the porcelain and the resin cement.

A) unetched porcelain
B) etched porcelain
C) unetched resin cement
D) etched resin cement

Question 12

The major drawback of all-ceramic restorations in the posterior of the mouth is the:

A) lack of esthetic appearance
B) fracture rate
C) inability to create an adequate occlusal anatomy versus the opposing occlusion
D) difficulty in creating an acceptable interproximal contact area

Question 13

Which of the following is true concerning matching the shade for ceramic restorations?

A) The ideal color for the area in which the shade will be matched is blue.
B) A composite guide may be used for a ceramic restoration.
C) Shade tabs should be moistened and individually held adjacent to the teeth to be matched.
D) Stare at the color of the shade tab and tooth for several seconds so the retina can adjust.

Question 14

Which of the following is the first layer of porcelain applied to the metal during fabrication of porcelain-metal restorations?

A) Incisal porcelain
B) Opaque porcelain
C) Body porcelain
D) Translucent porcelain

Question 15

Porcelain veneers may be slightly translucent to let the color of the underlying tooth come through or more ________ to hide the color of a darker natural tooth.

A) varnished
B) mottled
C) opaque
D) sandblasted

Question 16

Pressed ceramic veneers are ________ than feldspathic porcelain veneers and are too __________ for very dark teeth.

A) thinner; translucent
B) thinner; opaque
C) thicker; translucent
D) thicker; opaque

Question 17

The metals that are used as the core for the porcelain-fused-to-metal (PFM) crowns are alloys of specific metals that will form a/an __________ layer as the metal is heated.

A) eutectic
B) oxygen-inhibited
C) oxide
D) scintillating

Question 18

When a shade match is obtained, the shade tab should be _____ the tooth to be matched.

A) in front of
B) behind
C) in the same plane as
D) outside of the mouth, in contrast to

Question 19

Which of the following is true concerning lighting for shade taking?

A) Fluorescent lights emit more yellow light and incandescent lights emit more blue light.
B) A natural east light is considered a good light for shade taking.
C) Early morning and late afternoon light contains more yellow and orange light and less green and blue.
D) The bright light from the dental unit will tend to decrease the perceived brightness of the shade and increase the color intensity.

Question 20

The primary cause of porcelain failure is:

A) occlusal loading
B) firing defects
C) oral habits
D) poor diet

Question 21

Match the items with the correct description below.
A darker color

A)Long wavelength
B)Short wavelength
C)High value
D)Low value
E)High chroma

Question 22

Match the items with the correct description below.
Red color

A)Long wavelength
B)Short wavelength
C)High value
D)Low value
E)High chroma

Question 23

Which of the following is not a characteristic used for taking shades?

A) Translucency
B) Value
C) Chroma
D) Hue

Question 24

Match the items with the correct description below.
Violet color

A)Long wavelength
B)Short wavelength
C)High value
D)Low value
E)High chroma

Question 25

A CAD/CAM machined crown uses an optical scanner to:

A) design the crown
B) make the temporary
C) take the impression
D) design the prep

Question 26

When porcelain particles are melted and fused to metal, the process is known as:

A) smelting
B) firing
C) sintering
D) bonding

Question 27

Describe the different techniques for fabrication of ceramic restorations.

Question 28

Which of the following is a key advantage of low-fusing porcelains?

A) They are much stronger.
B) They are less abrasive.
C) They have an opaque layer.
D) They appear opalescent.

Question 29

Match the items with the correct description below.
A lighter color

A)Long wavelength
B)Short wavelength
C)High value
D)Low value
E)High chroma

Question 30

Which of the following could be a contraindication to placing veneers?

A) The teeth are rotated out of occlusion.
B) The natural tooth structure is dark.
C) The adjacent teeth have been bleached.
D) The patient has a diastema.

Question 31

Match the items with the correct description below.
An intense color

A)Long wavelength
B)Short wavelength
C)High value
D)Low value
E)High chroma

Question 32

Which of the following would also be taken into consideration when a tooth is shaded?

A) Translucency
B) Texture
C) Luster
D) All of the above

Question 33

The inside of the veneer is conditioned using a solution of:

A) phosphoric acid
B) hydrochloric acid
C) sulfuric acid
D) hydrofluoric acid

Question 34

The ideal color of the surrounding area during shade matching is:

A) tan
B) black
C) grey
D) white