4. Which of the following are true regarding opaque porcelains?
a. They are tetra-valent oxides.
b. They are di- valent oxides
c. They form a true chemical bond with certain metals.
d. They are smoother than enamel porcelains.
e. They fire at a lower temperature than enamel porcelains.
A. a,c,d B. b,c,d C. a,d,e D. b,e E. a,c?
6. The ideal thickness of the oxide layer for metal-ceramic bonding is:
a. 25 microns
b. 50 microns
c. 75 microns
d. 100 microns
e. Monomolecular
4. What dental material wears at the same rate (attrition) as that of tooth
enamel?
A. amalgam?
B. gold
C. composite resin
D. porcelain
E. zinc-phosphate cement
9. A set impression of alginate is __________ percent water. (by weight)
A. 20
B. 40
C. 60
D. 80
E. 90?
22. Why is it necessary to wait 24 hours fo r complete polymerization of a custom
acrylic tray?
a. To allow the tray to achieve maximum dimensional stability.
b. To allow the tray to achieve maximum strength.
c. To allow the tray to achieve maximum rigidity.
d. a, b, & c
e. a, b?
5. Which of the following composite materials is not indicated to restore the
incisal edge of a tooth?
a. Micro-hybrid
b. Macrofilled
c. Hybrid?
d. Microfilled
39. Which facts listed below is ideal for maximum bond strength in a porcelain fused
to metal restoration?
a. Mono-molecular oxide layer.
b. Bivalent-molecular oxide layer.
c. Multi-molecular oxide layer.
d. Negative electron charged oxide layer.
e. Positive electron charged oxide layer.
40. The ideal gap distance for a post-ceramic solder joint is:
a. 0.1 mm d. 0.5 mm
b. 0.15 mm - 0.3mm e. 0. 5 mm - 0.75 mm
c. 0.3 mm - 0.5 mm
41. The ideal gap distance for a pre-ceramic solder joint is:
a. 0.1 mm d. 0.5 mm
b. 0. 15 mm - 0.3mm e. 0. 5 mm - 0.75 mm
c. 0.3 mm - 0.5 mm
2. According to the law of beams a fixed partial denture with a three pontic span
will flex ___ times as much as a single pontic span
a. 8 times
b. 20 times
c. 16 times
d. 27 times?
e. 2 times
35. Why should epinephrine be used with caution?
1. Dosage control is a problem
2. It causes tachycardia
3. It is not a good hemostatic agent
4. It causes tissue damage more than other chemical agents
5. It discolors the gingival
a. 1,2,3
b. 2,3,5
c. 1,4,5
d. 1,2?
e. 3,5
with
1. glaucoma
2. asthma
3. congestive heart failure
4. lactating females
5. kidney stones
a. 2,3,4.
b. 1,2,3,4.?
c. 2,5.
d. 3,5
e. 3.
37. 1.Prior to taking an impression the retraction cord must be soaked with water
before removal from the gingival sulcus.
2. This prevents tearing of the sulcular epithelium and consequent bleeding.
a. 1 is true 2 is true and is a correct explanation for 1
b. 1 is false 2 is false.
c. 1 is true 2 is true but it is not a correct explanation for 1.
d. 1 is false 2 is true.
e. 1 is true 2 is false.
46. According to ADA specification 19, type IV and type V gypsum products are
capable of reproducing a _____ micron wide line
a. 5
b. 15
c. 20
d. 50
e. 100
3. Proper tissue retracton is accomplished by using
a. two #1 cords
b. two #0 cords
c. one #0 cord and one #1 cord
d. one #1 cord and one #2 cord
9. A custom tray must:
a. Extend 2 mm apical to the crest of the free gingival margin.
b. be rigid
c. be made the same day
d. have adequate time to polymerize (approx. 24 hours)
e. have adhesive placed at least 15 minutes before use
A) a,b,cB) a,c C) a,b,d,e? D) b,d,e E) all of the above
19. Which statement(s) on margination of a wax pattern are true?
a. The wax should be slightly overcontoured to allow for proper
contouring in gold.
b. After margination of the wax pattern it should be removed from the
die to evaluate for proper internal adaptation and then replaced on
the die to verify marginal fit.
c. The proper way to evaluate for marginal seal is to look closely
at the margin under good light, viewing the margin parallel to
the surface of the die.
d. When marginating, the wax should be re-adapted by first heating the
wax with a hot instrument so that the wax becomes soft but not
molten.
A) a,b,c B) b,c C) b,c,d D) c? E) None of the above
50. When evaluating your final wax pattern prior to margination you should
verify the following are correct:
irregularities
b. The external surface of the pattern is free of irregularities and is
smooth.
c. The contact area is concaved and rough to allow for finishing in gold.
d. Verify that the wax pattern is not in hyperocclusion by placing the
articulator pin on zero and closing the articulator several times to insure the
pin hits the incisal table.
e. The proximal contact areas are the proper dimension.
A) a,b,d,e B) a,b,e? C) a,c,d D) a,b,d E) c,d
13. The contact lens effect makes it possible to place a porcelain veneer finish
line at or above the crest of the free gingival margin and still maintain an
almost imperceptible junction between the restoration and the tooth.
Which of the statements are true regarding the contact lens concept?
a. The porcelain at the gingival should be opaque.
b. The porcelain at the gingival should be translucent.
c. The luting cement should be opaque.
d. The luting cement should be translucent.
e. The body of the porcelain should be translucent.
A) a,d B) b,c C) b,d,e D) a,c,e? E) b,d
I need help answering these questions thanks!!!!!!!!
