Definitive Casts & Dies Flashcards
A replica of the tooth surfaces, residual ridge areas, and/or other parts of the dental arch and/or facial structures used to fabricate a dental restoration and prosthesis:
Definitive (master or working) cast
Definitive cast=
master or working cast
The positive reproduction of the form of a prepared tooth in any suitable substance:
die
A metal pin used in some stone cast to remove die sections and replace them accurately in the original position:
die pin
In a die, the unprepared tooth structure apical to the finish line should be easily visible at:
0.5-1.0mm
Advantages of gypsum products:
- compatible will all impression materials
- ability to reproduce fine detail & sharp margins
- dimensional accuracy & stability
- easy to use
What is the disadvantage of gypsum products?
Susceptibility to abrasion
ADA Type I & II gypsum products:
Impression plaster/ model & mounting plaster
(plaster)
ADA Type III gypsum products:
Dental stone (general purpose cast)
ADA Type IV gypsum products:
High strength/lowest expansion (die stone)
ADA Type V gypsum products:
High strength/high expansion (die stone)
What are the advantages of automixing of gypsum product?
- homogenous
- more strength
- intended expansion
What is directly proportional to the water:powder ratio of gypsum products?
Setting times & manipulation
Regarding the water:powder ratio of gypsum products:
Describe the directly proportional ratio to increased water
Increased water= increased setting time; increased fluidity
What is indirectly proportional to the water:powder ratio of gypsum products?
Compression strength & setting expansion