Prostho 20-27

Question 1

20. Impression

Answer 1

is the negative likeness of the teeth and surrounding structures,
which contains those areas of the mouth where the planned restoration will be fabricated
as well as the surrounding hard and soft tissues
and their real surface configuration.

Question 2

21. Anatomical or preliminary impression

Answer 2

a negative likeness of the oral structures,
over dimensioned, records a static status.
It is made for the purpose of diagnosis,
treatment planning, documentation or
the fabrication of a special/individual tray.

Question 3

22. Precision impression

Answer 3

A highly precise impression which contains all the oral structures which are necessary to prepare a dental appliance,
especially the prepared tooth surfaces and from which a highly precise cast can be obtained

Question 4

23. Cast

Answer 4

a life-size likeness of some desired form.
A Cast is a positive reproduction of a part or parts of the oral cavity,
which is created by the pouring plaster into any type of impression.

Question 5

24. Diagnostic (Study) cast

Answer 5

life-size roduction of a part or parts of the oral cavity for the purpose of
study and treatment planning (inclination of teeth, planning of partial prosthesis, or implantation, orthodontics) or
documentation (record of initial and terminal state)

Question 6

24.1 Anatomical/preliminary cast

Answer 6

Positive copy of the oral structures,
a cast formed from the anatomical/preliminary impression for use in
diagnosis or the fabrication of an individual/special tray.

Question 7

25. Precision cast

Answer 7

a highly accurate positive reproduction of a part or parts of the oral cavity,
which is created by the pouring the plaster/dental stone into the precision impression .
It contains all the oral structures necessary to fabricate the dental appliance (also the covered tooth/die surfaces), 
the die (for which the crown, etc. is prepared) can be removed and inserted into the exact original position in the cast.

Question 8

26. Removable die system

Answer 8

a segmented final cast system that permits accurate removal and
replacement of dies of individually prepared teeth

Question 9

27. Temporary crown

Answer 9

A prosthetic appliance which is prepared for the time period between the tooth preparation and the delivery of the definitive crown.

Generally, it is fixed with temporary cement, in order to be able to remove and fit it again during try in sessions.