Lab Quizzes

Question 1

1. What is the ideal Total Occlusal Convergence angle for a posterior tooth preparation?

Answer 1

a. 6-10

Question 2

2. What is the occlusal clearance required on the functional cusp in a complete metal crown preparation?

Answer 2

a. 1.5mm

Question 3

3. The ratio of the occlusocervical/incisocervical dimension to the faciolingual dimension (OC/IC:FL) should be

Answer 3

a. 0.4

Question 4

4. Which margin design is well suited for complete metal crown?

Answer 4

a. Chamfer

Question 5

5. Whats the minimum occlusocervical height for a molar preparation?

Answer 5

a. 4mm

Question 6

1. Which of the following is NOT a bio-mechanical requirement for an interim restoration?

Answer 6

a. Taper

Question 7

2. Which of the following maintain positional stability of an interim restoration?

Answer 7

a. All of the above

Question 8

3. How should the emergence profile of the interim restoration look like?

Answer 8

a. Slightly concave

Question 9

4. When should a prefabricated crown be used as a provisional restoration?

Answer 9

a. Single crowns

Question 10

5. Which of the following activates the polymerization of polymer resins?

Answer 10

a. Camphorquinone

Question 11

6. What is the volumetric shrinkage of PMMA?

Answer 11

a. 8%

Question 12

7. Benzoyl Peroxide decomposes to free radical by which of the following processes?

Answer 12

a. Option A and B

Question 13

8. Which process occurs from reaction with eugenol and oxygen?

Answer 13

a. Termination

Question 14

1. How much of incisal reduction is required for a metal ceramic restoration?

Answer 14

a. 2-2.5mm

Question 15

2. What is the width and type of the facial margin for an anterior MCC?

Answer 15

a. Shoulder 1.2mm

Question 16

3. What is the width and type of the lingual/palatal margin for #8 MCC?

Answer 16

a. Chamfer 0.5mm

Question 17

1. The high coefficient of thermal expansion and release of residual stresses in a wax pattern can cause distortion, resulting in an inaccurate casting. Which of the following is useful in overcoming this problem?
   a. Complete evaporation of the wax components during wax application
   b. Investment soon after completion of wax pattern
   c. Storage of the wax pattern at an ambient temperature below 40oF
   d. Placement of the wax pattern in 100oF water bath for 30 minutes before investing

Answer 17

b. Investment soon after completion of wax pattern

Question 18

2. Quartz, cristobalite and tridymite function in dental casting investments as:
   a. Refractory components
   b. Binders
   c. Modifiers

Answer 18

a. Refractory components

Question 19

3. When casting type III gold alloys (≤1200oF), which type of dental investment is used?
   a. Phosphate- bonded investment
   b. Gypsum- bonded investment
   c. Silica- bonded investment
   d. Non of the above

Answer 19

b. Gypsum- bonded investment

Question 20

4. The types of expansion with which a gypsum-bonded investment may be involved are:
   a. Setting expansion
   b. Hygroscopic expansion
   c. Thermal expansion
   d. All of the above

Answer 20

d. All of the above

Question 21

5. The ratio of water to powder for Type IV stone should be weighed / measured as recommended by the manufacturer, and is approximately:
   a. 20 cc / 100g
   b. 30 cc / 100 g
   c. 40 cc / 100 g
   d. 50 cc / 100g

Answer 21

a. 20 cc / 100g

Question 22

6. The internal surface of a type III gold casting is best prepared for cementation by:
   a. Acid etching
   b. Roughening the surface with a carbide bur
   c. Air abrasion (sandblast) with 50 micron alumina
   d. Thorough washing and drying
   e. Both C and D

Answer 22

e. Both C and D

Question 23

1. In a clinical setting, if you were trying in #4 lithium disilicate crown, which of the following would you check first?
   a. Occlusion
   b. Internal fit
   c. Proximal fit
   d. Marginal integrity

Answer 23

c. Proximal fit

Question 24

2. Which of the following would you adjust after fit checking a glass ceramic restoration?
   a. Intaglio of the crown only
   b. The tooth only
   c. Both of the above
   d. None of the above

Answer 24

b. The tooth only

Question 25

3. RMGI cement can be used to cement all of the following restorations EXCEPT?
   a. Full Gold Crown
   b. Porcelain fused to metal
   c. Zirconia
   d. Lithium Disilicate

Answer 25

d. Lithium Disilicate

Question 26

4. Proximal contacts of a crown can be checked by using which of the following materials?
   a. Shim stock
   b. Accuflim articulating paper
   c. Occlude spray
   d. All of the above
   e. Non of the above

Answer 26

d. All of the above

Question 27

5. Which of the following situations can lead to an open margin?
   a. Heavy proximal contact
   b. Internal binding of the crown
   c. Both A and B
   d. Both A and B along with heavy occlusal contacts

Answer 27

c. Both A and B

Question 28

Which of following characteristics is NOT -

Answer 28

short working type

Question 29

Question about vinyl polysiloxane

Question 30

How much space between tray -

Answer 30

2-3mm

Question 31

Characteristic of custom tray -

Answer 31

all of the above

Question 32

Purpose of making preliminary impression -

Answer 32

all of the above