Lecture 5-Mouth Preps

Question 1

For a TOOTH SUPPROTED segment (class III), how “tall” occlusal-gingival should the guide plane be?

Answer 1

2 to 4 mm

Question 2

For an extension base (class I and II), a guide plane should be how “tall” occlusal-gingival?

Answer 2

1.5 to 2 mm (vs 2-4mm for class III)

Question 3

What do you do first: Polish your guide plane or take an impression/pour to check correct angles?

Answer 3

Impression/pour THEN polish

Question 4

What is the recommended bur to use for a cingulum rest?

Answer 4

an inverted cone

Question 5

What is the preferred bur for an incisal rest?

Answer 5

round ended tapered diamond

Question 6

An occlusal rest seat is basically _______ in shape

Answer 6

triangular

Question 7

All features of the rest seat are gently _________.

Answer 7

rounded

Question 8

You freggin missed this one PAY ATTENTION: How wide should the rest seat prep be in a BUCCAL-LINGUAL direction?

Answer 8

1/2 of the occlusal table (at its WIDEST-on the marginal ridge)

Question 9

The enclosed angle formed by the floor of the rest seat and the proximal surface of the tooth must be less than _____ degrees

Answer 9

90

Question 10

The preparation is finished using a ______ stone in a low-speed handpiece.

Answer 10

green

Question 11

The preparation is then polished using a _________- containing rubber point in a low-speed handpiece

Answer 11

carborundum

Question 12

T/F-you take off more when preparing a tooth that will hold a survey crown.

Answer 12

TRUE. You prep in the rest area for consistent metal thickness

Question 13

When making a PFM survey crown, how far (in mm) should metal borders extend beyond the proposed rest borders?

Answer 13

1mm

Question 14

What are the dimensions of the handle on your custom tray?

Answer 14

20mm x 20mm

Question 15

Impression types: The surface contour of the ridge when it is not supporting a load

Answer 15

Anatomic

Question 16

Impression types: The surface contour of the ridge when it is supporting a functional load

Answer 16

Functional

Question 17

Which impression type represents the hard and soft tissues at rest


Answer 17

Anatomical Impression

Question 18

Which type of impression is a pressure less impression?

Answer 18

Mucostatic

Question 19

What are the two types of functional impressions?

Answer 19

1.physiologic 2. selective pressure

Question 20

Which type of impression? (2 descriptors!)…This technique places an occlusal load on the impression tray while the impression is being made; therefore, placing pressure on the ridges

Answer 20

physiologic OR functional impression

Question 21

Which impression type is accomplished by providing relief in the tray in certain areas and letting the tray contact the tissue in other areas?

Answer 21

Selective Pressure

Question 22

When making our MASTER CAST, which type of stone do we use?

Answer 22

die stone

Question 23

What are the three metals used in the casting of RPDs? What %weight do these three metals comprise in MOST dental restorations?

Answer 23

Chromium, Cobalt, Nickel…they account for 82-92%wt of most alloys used for dental restorations

Question 24

What is the breakdown for the amount of the BIG THREE metals in VITALLIUM???

Answer 24

1.Chromium-30% 2.Cobalt 63% 3.Nickel-0%

Question 25

What is the breakdown for the amount of the BIG THREE metals in TICONIUM???

Answer 25

1. Chromium-17% 2.Cobalt 0% 3.Nickel-63% (BOO!)

Question 26

What is the breakdown for the amount of the BIG THREE metals in GOLD-BASED???

Answer 26

1. Chromium-0% 2.Cobalt 0% 3.Nickel-0% (56% gold, 14% Copper)

Question 27

What does the lab use to duplicate the cast you send in?

Answer 27

agar (reversible hydrocolloid)

Question 28

What is the cast compounded to withstand high temperatures without disintegrating and, incidentally, to perform certain functions relative to burnout and expansion of thee mold

Answer 28

the Refractory cast