Chapter 6

Question 1

Diagnostic casts allow for:

Answer 1

evaluation of hard and soft tissue anatomy wo pt., determination of necessary preprosthetic surgery, mounted on articulator, and interocclusal space evaluated, base from which custom impression trays are fabricated.

Question 2

Preliminary impressions are made using:

Answer 2

irreversible hydrocolloid

Question 3

Disadvantage of using irreversible hydrocolloid:

Answer 3

high viscosity, often displaces, soft tissues of vestibule, resulting in overextended vestibule –> overextended impression –> over extended resulting cast

Question 4

Vestibular inaccuracy is unacceptable in this case:

Answer 4

diagnostic or master cast for a complete denture patient.

Question 5

Stock tray choice:

Answer 5

about 5–6 mm (1/4 inch)even spacing between the tray and the tissues. For the right-handed dentist, the correct, approximately 5–6 mm (1/4 inch)between the tissues and impression tray.

Question 6

Posterior border of impression tray should be here:

Answer 6

lightly beyond thehamular notches for the maxillary arch and over the retromolar pads for the mandibu-lar arch