Chapter 9: Dental Ceramics

Question 1

Porcelain restorations have?

Answer 1

Great stain resistance

Question 2

Porcelain bonds to metal by which mechanisms?

Answer 2

Fusion with oxides on the surface of the metal

Question 3

The main advantage of all-ceramic crowns over porcelain-bonded-to-metal crowns is?

Answer 3

Their superior esthetics

Question 4

The main drawback of feldspathic porcelain for all-porcelain crowns is?

Answer 4

Their tendency to fracture

Question 5

An in-office CAD/CAM system for ceramic restorations provides all of the following except one? Which one is the exception?
A. The restoration does not have to fabricated in an outside laboratory
B. A provisional crown is not needed.
C. The procedure can be completed in one visit.
D. Local anesthesia is not needed.

Answer 5

Local anesthesia is not needed

Question 6

The basic color of the tooth is called?

Answer 6

Hue

Question 7

All of the following should be avoided when taking the shade of a tooth except one. Which one?
A. Lipstick on the patient
B. Brightly colored clothing
C. Dirty teeth (covered with plaque)
D. Neutral wall colors in the room

Answer 7

Neutral wall colors in the room

Question 8

All of the following materials should be avoided around ceramic restorations except one. Which one?
A. Acidulated topical fluoride products
B. Alginate impression material
C. Coarse prophy paste
D. Acid etchant

Answer 8

Alginate impression material

Question 9

The impression for a CAD/CAM crown is?

Answer 9

Done by capturing an image of the prepared tooth with an optical scanner

Question 10

When preparing a porcelain-fused-to-metal crown, the technician applies feldspathic porcelain in layers to the metal coping. The initial layer is?

Answer 10

Body porcelain to mimic dentin

Question 11

On occasion, special porcelain stains are used on the surface of the porcelain. These stains contain metal oxides and are used to?

Answer 11

Mimic white spots or fine crack lines to resemble adjacent teeth.

Question 12

Which one of the following statements about porcelain veneers is false?
A. Porcelain veneers are more durable than composite veneers.
B. Porcelain veneers must be handled carefully when one is trying them on, because they are very fragile until bonded to the tooth.
C. It is difficult to mask a darkly colored tooth with a porcelain veneer.
D. Porcelain veneers are usually cemented with zinc phosphate or glass ionomer cement.

Answer 12

Porcelain veneers are usually cemented with zinc phosphate or glass ionomer cement.

Question 13

When assisting the dentist with taking the shade of a tooth, the dental assistant should?

Answer 13

Cover brightly colored clothing with a pastel, neutral colored bib

Question 14

Which ceramic material is the strongest and most fracture resistant?

Answer 14

Zirconia

Question 15

Which ceramic material is the most opaque, and therefore, the least esthetic?

Answer 15

Zirconia

Question 16

For anterior ceramic restorations the ceramic material used at the incisal edge tends to be what?

Answer 16

Translucent

Question 17

The lightness and darkness of a color is referred to as what?

Answer 17

Value

Question 18

Which ceramic material is not etched by hydrofluoric acid in preparation for cementation but may be sandblasted internally instead?

Answer 18

Zirconia

Question 19

Porcelain veneers are bonded to the tooth with resin cement. This provides the opportunity to do all of the following except one. Which one?
A. Increase the strength of the restoration
B. Increase the retention of the restoration
C. Slightly modify the shade of the cemented restoration with a colored resin cement
D. Whiten the tooth with the acid etchant

Answer 19

Whiten the tooth with the acid etchant

Question 20

All of the following considerations should be applied when finishing or polishing a ceramic material except one. Which one?
A. Use slow speed
B. Use a coarse diamond bur for adjustments
C. Use light pressure
D. Progress from medium abrasives to finer ones

Answer 20

Use a corse diamond bur for adjustments

Question 21

All of the following are processing methods for ceramic materials except one. Which one?
A. Sintering
B. Heat pressing
C. Cold curing
D. CAD/CAM

Answer 21

Cold curing

Question 22

When one is taking photographs of the teeth to send to the dental laboratory to help convey the correct shade, what is the proper location for the shade tab in the photograph?

Answer 22

In the same place as the tooth being matched