2010 Released Qs And Ans 1

Front 1

Which of the following methods of
instrument sterilization uses the lowest
temperature?
A. Steam autoclave.
B. Dry heat oven.
C. Ethylene oxide method.
D. Glass bead sterilizer.
E. Alcohol autoclave.

Back 1

C. Ethylene oxide method.

Front 2

When root canals are treated topically with
antibiotics rather than with disinfectants
1. a greater success rate results.
2. the same rules of mechanical
preparation and filling must be
observed.
3. treatment may be completed in fewer
appointments.
4. there is greater assurance that all
micro-organisms are destroyed.
5. there is a danger of sensitizing
patients to antibiotics.

Back 2

2. the same rules of mechanical
preparation and filling must be
observed.
5. there is a danger of sensitizing
patients to antibiotics.

Front 3

The antibiotic of choice for infections of
pulpal origin is
A. penicillin V.
B. lincomycin.
C. erythromycin.
D. tetracycline.

Back 3

A. penicillin V.

Front 4

Endodontic therapy is
CONTRAINDICATED in teeth with
A. inadequate periodontal support.
B. pulp stones.
C. constricted root canals.
D. accessory canals.
E. curved roots.

Back 4

A. inadequate periodontal support.

Front 5

Periapical surgery is
CONTRAINDICATED for a tooth that
has a
A. large periapical rarefaction.
B. fistula related to a periapical lesion.
C. vertical root fracture.
D. fracture of the root apex and a
necrotic pulp.
E. a post and core retained crown.

Back 5

C. vertical root fracture.

Front 6

A patient telephones and tells you he has
just knocked out his front tooth but that it
is still intact. Your instructions should be
to
A. put the tooth in water and come to
your office at the end of the day.
B. wrap the tooth in tissue and come to
your office in a week's time.
C. put the tooth in alcohol and come to
your office immediately.
D. place tooth under the tongue and
come to your office immediately.
E. place the tooth in milk and come to
your office immediately.

Back 6

E. place the tooth in milk and come to
your office immediately.

Front 7

The placement of a retentive pin in the
proximal regions of posterior teeth would
MOST likely result in periodontal
ligament perforation in the
A. mesial of a mandibular first
premolar.
B. distal of a mandibular first premolar.
C. distal of a mandibular first molar.
D. mesial of a mandibular first molar.

Back 7

C. distal of a mandibular first molar.

Front 8

For a cast gold restoration, a gingival
bevel is used instead of a shoulder because
a bevel
1. protects the enamel.
2. increases retention.
3. improves marginal adaptation.
4. increases the thickness of gold.

Back 8

1. protects the enamel.
3. improves marginal adaptation.

Front 9

Firm contact between approximating teeth
is important because it
A. locates the marginal ridges of each
tooth.
B. keeps the teeth from having any
movement during function.
C. insures proper cusp form and
increases masticatory efficiency.
D. stabilizes the dental arches and gives
protection to the gingival papillae.

Back 9

D. stabilizes the dental arches and gives
protection to the gingival papillae.

Front 10

In determining the ideal proximal outline
form for a Class II amalgam cavity
preparation in a molar the
1. axial wall should be 1.5mm deep.
2. gingival cavosurface margin must
clear contact with the adjacent tooth.
3. proximal walls diverge occlusally.
4. facial and lingual proximal
cavosurface margins must just clear
contact with the adjacent tooth.

Back 10

2. gingival cavosurface margin must
clear contact with the adjacent tooth.
4. facial and lingual proximal
cavosurface margins must just clear
contact with the adjacent tooth.

Front 11

In complete dentures with teeth set in a
normal horizontal overlap relationship, the
selective grinding rule for removing
premature contacts on the working side is
to grind
A. only the fossae of teeth.
B. the buccal cusps of maxillary and
lingual cusps of mandibular teeth.
C. only the mandibular teeth.
D. lingual and buccal cusps of maxillary
teeth.
E. the maxillary and mandibular
cuspids.

Back 11

B. the buccal cusps of maxillary and
lingual cusps of mandibular teeth.

Front 12

The inferior border of the lingual bar of a
mandibular removable partial denture
should
A. displace the lingual frenum.
B. be in contact with the cingula of the
incisor teeth.
C. be superior to the gingival border.
D. be as inferior as the movement of the
frenum of the tongue will permit.

Back 12

D. be as inferior as the movement of the
frenum of the tongue will permit.

Front 13

Movement of a mandibular distal
extension (Class 1) partial denture away
from the denture bearing tissues when the
patient opens is primarily caused by
A. xerostomia.
B. group function occlusion.
C. non-passive retentive arms.
D. overextended borders.

Back 13

D. overextended borders.

Front 14

To evaluate an existing occlusion,
diagnostic casts should be mounted on an
articulator in
A. centric relation.
B. balancing occlusion.
C. either centric relation or balancing
occlusion.
D. horizontal protrusive relation

Back 14

A. centric relation.

Front 15

The stiffness of a material can best be
described by the
A. modulus of elasticity.
B. percentage elongation.
C. modulus of resilience.
D. elastic limit.

Back 15

A. modulus of elasticity.

Front 16

In a porcelain fused to gold restoration,
which property must be modified between
porcelain and gold to reduce the bond
shear stress?
A. Compressive strength.
B. Tensile strength.
C. Modulus of elasticity.
D. Thermal coefficient of expansion.
E. Yield strength.

Back 16

D. Thermal coefficient of expansion.

Front 17

An excessively thick palatal bar of a
maxillary partial denture will
A. cause injury to the abutment teeth.
B. distort under occlusal stress.
C. irritate the palatal tissues.
D. cause difficulty in swallowing.

Back 17

D. cause difficulty in swallowing.

Front 18

A distal extension removable partial
denture is one that receives its support
A. from the tissues only.
B. mostly from the tissues.
C. mostly from the abutment teeth.
D. equally from the abutment teeth and
the tissues.

Back 18

B. mostly from the tissues.

Front 19

For a patient with new complete dentures,
errors in centric occlusion are best
adjusted by
A. directing the patient to close the
jaws, bringing the teeth into
occlusion.
B. having the patient close in centric
occlusion and making a transfer
record to the articulator.
C. having the patient leave the dentures
out of the mouth for 24 hours.
D. remounting the dentures in the
articulator using remount casts and
new interocclusal records.

Back 19

D. remounting the dentures in the
articulator using remount casts and
new interocclusal records.

Front 20

Biologically, the gingival aspect of a
pontic which touches the healed alveolar
ridge would be
A. convex in the mesio-distal direction.
B. concave in the facio-lingual
direction.
C. convex in all directions.
D. shaped for pleasant esthetics.
E. in line with the height of the residual
ridge.

Back 20

C. convex in all directions

Front 21

When the mandible makes hinge closure
in its most retruded, unstrained position
and all teeth meet in maximum
intercuspation simultaneously, the
condition is described as
A. centric occlusion.
B. group function.
C. balanced occlusion.
D. centric occlusion coinciding with
centric relation.

Back 21

D. centric occlusion coinciding with
centric relation.

Front 22

The principal advantage of polyether
impression materials over polysulfide
polymer impression materials is
A. longer shelf life.
B. superior accuracy.
C. superior surface on the cast.
D. less dimensional change with time.

Back 22

D. less dimensional change with time.

Front 23

The polishing of an amalgam restoration
A. should not be performed before
24 hours after insertion.
B. completely prevents tarnish from
occurring.
C. removes the mercury rich surface
layer of the amalgam.
D. is more permanent if the surface is
heated during the procedure.

Back 23

A. should not be performed before
24 hours after insertion.

Front 24

A decrease in the particle size of the
amalgam alloy will affect the amalgam by
A. increasing flow.
B. decreasing expansion.
C. retarding setting rate.
D. increasing early strength.

Back 24

D. increasing early strength.

Front 25

Gold alloy can be given a white colour by
introducing sufficient
A. zinc.
B. copper.
C. cadmium.
D. palladium.

Back 25

D. palladium.

Front 26

The use of a reservoir on the sprue of a
wax pattern decreases
A. volumetric changes in the casting.
B. casting porosity from inclusion of
gases.
C. casting porosity from inclusion of
foreign bodies.
D. casting porosity during solidification

Back 26

D. casting porosity during solidification

Front 27

The interocclusal distance (freeway space)
A. is the difference between occlusal
vertical dimension and hinge-axis
registration.
B. is the difference between occlusal
vertical dimension and rest vertical
dimension.
C. is usually l0 mm in the premolar
region.
D. is the distance between centric
occlusion and centric relation.

Back 27

B. is the difference between occlusal
vertical dimension and rest vertical
dimension.

Front 28

Marginal leakage of a composite resin
restoration will
A. not be detectable.
B. be minimized by use of a bonding
agent.
C. decrease with longevity.
D. None of the above.

Back 28

B. be minimized by use of a bonding
agent.

Front 29

The coefficient of thermal expansion of
composite resins is
A. greater than that of enamel.
B. the same as that of enamel.
C. less than that of enamel.
D. the same as that of amalgam.
E. the same as that of glass ionomer
cement.

Back 29

A. greater than that of enamel.

Front 30

Molecular attraction between unlike
substances is called
A. adhesion.
B. cohesion.
C. syneresis.
D. absorption.

Back 30

A. adhesion

Front 31

The modulus of elasticity of a material is
determined by
A. dividing stress by strain below elastic
limit.
B. dividing strain by stress.
C. multiplying proportional limit by
strain.
D. squaring proportional limit and
dividing by strain.

Back 31

A. dividing stress by strain below elastic
limit.

Front 32

Polysulfide rubber base impressions
should be
A. poured immediately.
B. allowed to stand a half hour before
pouring.
C. immersed in a fixing solution before
pouring.
D. immersed in water 10 minutes before
pouring.
E. coated with a thin film of separating
medium.

Back 32

B. allowed to stand a half hour before
pouring.

Front 33

Distortion of a wax pattern is mainly due
to
A. insufficient plasticity during
manipulation.
B. insufficient bulk of material.
C. relaxation of stresses introduced
during manipulation.
D. insufficient paraffin ingredient.
E. refrigeration.

Back 33

C. relaxation of stresses introduced
during manipulation.

Front 34

Which of the following is the hardest?
A. Amalgam.
B. Enamel.
C. Composite resin.
D. Silicate cement.
E. Type IV gold alloy.

Back 34

B. Enamel.

Front 35

The greatest dimensional change in
denture bases will occur
A. after the dentures have been in the
mouth 24~hours.
B. when the dentures have been stored
in tap water at room temperature.
C. when a complete denture opposes
natural teeth.
D. at the time the dentures are removed
from the flask.

Back 35

D. at the time the dentures are removed
from the flask.

Front 36

Glass ionomer cement restorations are
indicated for
A. root caries.
B. incisal edge fractures.
C. Class II lesions in adults.
D. locations where esthetics are
important.

Back 36

A. root caries.

Front 37

Varying the mercury content of an
amalgam results in which of the
following?
A. The higher the mercury content the
greater the strength.
B. The higher the mercury content the
less the flow.
C. The lower the mercury content the
greater the flow.
D. The lower the mercury content the
greater the strength.

Back 37

D. The lower the mercury content the
greater the strength.

Front 38

Dental amalgam restorations
A. show decreased flow when the tin
mercury phase is increased.
B. contain nickel to increase the yield
strength.
C. show decreased corrosion and
marginal breakdown when the
copper tin phase is increased.
D. contain zinc to reduce galvanic
corrosion.

Back 38

C. show decreased corrosion and
marginal breakdown when the
copper tin phase is increased

Front 39

After the cementation of a crown, which
of the following is most likely to result in
chronic gingivitis?
A. A subgingival finish line.
B. A supragingival finish line.
C. An undercontoured crown.
D. An overcontoured crown.

Back 39

D. An overcontoured crown.

Front 40

In fixed bridge construction, where the
vertical dimension has to be increased, the
most important consideration is whether
A. there is sufficient tooth bulk in the
abutment teeth for crown retention.
B. the inter-occlusal distance will be
physiologically acceptable.
C. the aesthetic appearance of the
patient will be improved.
D. an unfavorable crown-root ratio may
develop.

Back 40

D. an unfavorable crown-root ratio may
develop.

Front 41

The gingival tissues remain healthier when
margins of crowns are placed
A. about lmm below the gingival crest.
B. about 5mm below the gingival crest.
C. above the gingival crest.
D. at the gingival crest.

Back 41

C. above the gingival crest.

Front 42

The articular disc of the
temporomandibular joint is moved by the
A. lateral (external) pterygoid muscle.
B. medial (internal) pterygoid muscle.
C. temporal muscle.
D. fibres of the masseter muscle.
E. upper fibres of the buccinator
muscle.

Back 42

A. lateral (external) pterygoid muscle

Front 43

The maxillary labial frenum contains
A. fibres of the orbicularis oris muscle.
B. fibres of the levator anguli oris
muscle.
C. fibres of the levator labii superioris
muscle.
D. no muscle fibres.

Back 43

A. fibres of the orbicularis oris muscle.

Front 44

Which of the following is classified as a
muscle of mastication?
A. Temporalis.
B. Buccinator.
C. Digastric.
D. Mylohyoid.

Back 44

A. Temporalis.

Front 45

Which of the following bacterial types is
implicated in the initiation of gingivitis?
A. Streptococcus salivarius.
B. Streptococcus mutans.
C. Leptothrix buccalis.
D. Actinomyces viscosus.

Back 45

B. Streptococcus mutans.

Front 46

Which is the LEAST effective method of
instrument sterilization?
A. Chemical solutions.
B. Dry heat.
C. Chemical autoclave.
D. Steam autoclave.

Back 46

A. Chemical solutions.

Front 47

Anti-plaque mouth washes should be
A. adsorbed onto teeth and other oral
surfaces.
B. activated by salivary amylase.
C. deactivated by salivary amylase.
D. absorbed by mucosa.

Back 47

B. activated by salivary amylase.

Front 48

Which of the following penicillins is
LEAST resistant to the level of acidity
found in the stomach?
A. Benzylpenicillin.
B. Phenoxymethylpenicillin.
C. Amoxicillin.
D. Ampicillin.

Back 48

A. Benzylpenicillin.

Front 49

In congestive heart failure, a glycoside
that increases the force of myocardial
contraction is
A. digitoxin.
B. quinidine.
C. amyl nitrite.
D. procainamide hydrochloride

Back 49

A. digitoxin.

Front 50

An excess of which hormone is associated
with increased sensitivity to epinephrine?
A. Testosterone.
B. Parathyroid hormone.
C. Insulin.
D. Thyroxin.
E. Estrogen.

Back 50

D. Thyroxin