Question

Which of the following statements correctly describes the pouring methods used to create the base portion of a dental model?

a) In the reversible hydrocolloid method, the impression is poured immediately after it is taken.
b) In the irreversible hydrocolloid method, the impression is poured immediately after it is taken.
c) In the reversible hydrocolloid method, the impression is poured after the material has cooled and solidified.
d) In the irreversible hydrocolloid method, the impression is poured before it sets.

Answer 1

Option b describes the process accurately: In the irreversible hydrocolloid method, the impression is poured immediately after it is taken to prevent dimensional changes.

Step-by-step explanation:

The correct statement that describes the pouring methods used to create the base portion of a dental model is: b) In the irreversible hydrocolloid method, the impression is poured immediately after it is taken. This method involves using alginate as an impression material, which cannot revert to its original sol state once it has transformed into a gel. With irreversible hydrocolloids, it is important to pour the model immediately after making the impression to prevent dimensional changes that occur on standing. Unlike reversible hydrocolloids such as agar, which needs to be cooled and solidified before pouring, alginate must be used while still in its unset, pliable state.