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What is the most common restoration in fixed prosthodontics?
Porcelain-metal restorations (PBM/PFM)
What is the main advantage of the porcelain-metal restorations?
the strength of the restoration from the bond between metal and porcelain
What is it that forms the strong bond between the metal and the porcelain of PBM/PFM restorations?
As the metal is heated it forms an OXIDE layer, when the porcelain is applied to the metal, the porcelain chemically fuses to the oxides on the metal
What are most porcelain failures related to?
the chemical bond between porcelain and OXIDES upon occlusal loading
How thick is the metal used in PBM/PFM restorations?
pretty thin: 0.3-0.5 mm thick
What type of crowns are low fusing porcelain?
porcelain jacket crowns
Is the fracture rate in the posterior due to occlusal loading higher in all ceramic or PFM crowns?
Name 4 ways all ceramic crowns are used despite their fracture rate.
Name 2 advantages of using low fusing porcelain over regular porcelain.
less wear (less abrasive) on opposing teeth
easier to polish
What is an advantage of low fusing porcelain to PFM?
there is no need for an opaque layer to mask the metal
What are 2 main advantages of computer assisted -CAD/CAM restorations?
no die and no temporary crown needed
optical scanner makes 'impression' of the crown prep and adjacent teeth
Name 3 purposes for veneers
cover defects such as dark teeth - so they are more opaque
reshape crooked teeth (look like they had orthodontics)
Do veneers bond better to enamel or dentin?
What is added to veneers to enhance the bond between porcelain and resin cement?
SILANE coupling agent added to ETCHED porcelain surface
how are veneers 'conditioned'?
with hydrofluoric acid
You should take the shade of the tooth __________ the tooth prep and ________ placement of rubber dam
_____ is tooth color
_______ is intensity of the color
_______ is the lightness or darkness of the tooth
do dry teeth appear lighter or darker?
fluorescent lights make the shade of the tooth look more _________. Incandescent lights make the shade of the tooth look more _________.
What is the best light to use in taking the shade of someones tooth?
Natural North light
The dental unit light increases _______________ and decreases ______________
true or false. It is best to use a neutral background color for matching the shade of a tooth; the pastel blue pt bib is fine.
both are true
What are 3 surface characteristics that are noted about shade when sending it in?
What type of fluoride should you use in the presence of any type of restoration?
for test two