Chapter 9: Dental Ceramics Flashcards
Porcelain restorations have?
Great stain resistance
Porcelain bonds to metal by which mechanisms?
Fusion with oxides on the surface of the metal
The main advantage of all-ceramic crowns over porcelain-bonded-to-metal crowns is?
Their superior esthetics
The main drawback of feldspathic porcelain for all-porcelain crowns is?
Their tendency to fracture
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.
Local anesthesia is not needed
The basic color of the tooth is called?
Hue
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
Neutral wall colors in the room
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
Alginate impression material
The impression for a CAD/CAM crown is?
Done by capturing an image of the prepared tooth with an optical scanner
When preparing a porcelain-fused-to-metal crown, the technician applies feldspathic porcelain in layers to the metal coping. The initial layer is?
Body porcelain to mimic dentin
On occasion, special porcelain stains are used on the surface of the porcelain. These stains contain metal oxides and are used to?
Mimic white spots or fine crack lines to resemble adjacent teeth.
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.
Porcelain veneers are usually cemented with zinc phosphate or glass ionomer cement.
When assisting the dentist with taking the shade of a tooth, the dental assistant should?
Cover brightly colored clothing with a pastel, neutral colored bib
Which ceramic material is the strongest and most fracture resistant?
Zirconia
Which ceramic material is the most opaque, and therefore, the least esthetic?
Zirconia
For anterior ceramic restorations the ceramic material used at the incisal edge tends to be what?
Translucent
The lightness and darkness of a color is referred to as what?
Value
Which ceramic material is not etched by hydrofluoric acid in preparation for cementation but may be sandblasted internally instead?
Zirconia
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
Whiten the tooth with the acid etchant
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
Use a corse diamond bur for adjustments
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
Cold curing
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?
In the same place as the tooth being matched
