EXTRA COR REST - FVC Crowns - Full Veneer Crowns Flashcards
5 advantages.
- strong
- similar hardness to enamel
- inert - won’t corrode in the mouth
- minimal tooth reduction needed
- simple to make
3 disadvantages.
poor aesthetic - unless u like gold ✨
very expensive - esp gold
inert - it won’t bond to tooth
when would you use FVC? (3)
- restore function
- posterior teeth where aesthetics aren’t as important
- teeth with limited height, as least occlusal reduction is needed with FVC
how do you take an impression?
use a different colour for the tooth of interest
- use a base colour for the entire arch
Steps of Preparation. PIML SICF
- prepare the tooth
- impression
- model and die preparation
- lost wax technique
- spruing
- investing
- metal casting
- metal finishing and polishing
what is the model and die preparation?
- a cast model is made from the impression
- the tooth is painted to create a die spacer = a uniform space for the cement
what is the lost wax technique?
constructing the crown using wax to create a mould, to be filled with molten alloy
what is spruing?
a sprue former, a base uses a channel (sprue) from where the molten metal can be poured into the mould
what is investing?
- the mould is surrounded with the investing material metal
- wait for investing material to dry
- remove it
- leaves behind a cavity in the shape of the restoration and channels
done within a casting ring with a ring liner
describe metal casting
- heat applied
- wax removed
- molten metal alloy moves into the mould
describe metal finishing and polishing.
- sprue is removed
- crown is placed onto the model, ensure fit
- polish the crown to get a shine
how do you prepare an FVC? reductions, taper and bur
occlusal - 1mm
buccal and lingual - 0.5mm
taper = 6-12 degrees
bur = chamfer and short needle for contact
