Dr.

Jawad Tariq
1
(KCD)

VIJAY PRATAB
6: Sprues can be fabricated from all of the
DENTAL MATERIALS BCQs following, except
1: wax
2: resin
1: The limited shelf-life of condensation 3: stainless steel
silicones is usually the result of deterioration of 4: plastic
which of thefollowing components? 5: none of the above
1: Lithopone Ans: 5
2: Tin component
3: Diurethyl siloxane 7: Wrought gold alloys are used in dentistry
4: Platinum salt primarily as
Ans: 2 1: full crowns
2: inlays
2: The restorative resins currently most popular 3: wires
are the 4: arch bars
1: unfilled direct filling, light-curing resins 5: metal ceramics
2: filled polyurethane resins Ans: 3
3: acrylic resins
4: microfilled composite resins 8: A Type IV partial denture gold alloy exceeds a
Ans: 4 base-metal alloy in numerical value in
1: compressive strength
3: The decrease in the marginal leakage of an 2: casting shrinkage
amalgam restoration is primarily the result of 3: hardness
1: using cavity varnish 4: specific gravity
2: water sorption 5: modulus of elasticity
3: expansion of the alloy Ans: 4
4: formation of corrosion products
Ans: 4 9: Heating a gypsum investment to 1000°C will
result in the liberation of
4: The pH of zinc phosphate cement be-comes 1: silver sulfide
neutral in 2: carbon monoxide
1: 30-60 minutes 3: hydrogen
2: 24-48 hours 4: sulfur dioxide
3: 1 week Ans: 4
4: 4-6 hours
Ans:2 10: Crystallinity of a polymer will result in an
increase in its
5: Which metals expand on from the molten 1: molding temperature
state? 2: solubility
1: Platinum and palladium 3: ductility
2: Iridium and lead 4: none of the above
3: Indium and strontium Ans: 1
4: Bismuth and antimony 11: coupling agents in composite resins act to
5: None of the above 1: increase cross-linking
Ans: 4 2: bind the matrix together
 Dr. Jawad Tariq
2
(KCD)

3: bind the filler together

4: bind the filler to the matrix 17: Copper and silver in dental amalgam
Ans: 4 1: increase compressive strength and expansion
2: aid in amalgamation and decrease expansion
12: The mercury content of the finished 3: reduce hardness and expansion only
amalgam restoration should be approximately 4: decrease hardness, flow, expansion and
1: 40% compressive strength
2: 50% Ans: 1
3: 60%
4: less than 35% 18: When epoxy resins are used for die
Ans: 2 fabrication, the resultant die will
1: be slightly undersize
13: The lost wax technique was first described 2: not burn out in the furnace
in 3: have poor abrasion resistance
1: 1907 by Taggart 4: have low strength
2: 1930 by Skinner 5: all of the above
3: 1898 by Hollenback Ans: 1
4: 1765 by jelenko
Ans: 1 19: Which of the following cannot result in
surface roughness or irregularities of gold
14: Which of the following properties would be castings?
of least importance, when selecting an 1: Under heating the mold
impression 2: Heating the alloy to too high a temperature
material? 3: Employing too high casting pressures
1: Dimensional stability 4: Prolonged heating of the mold
2: Biocompatibility 5: None of the above
3: Flow Ans: 5
4: Adhesion
5: Ease of manipulation 20: Silicate cement powders are made up of
Ans:4 oxides or fluorides of all of the following, except
1: aluminium
15: The polymer: monomer ratio for heat-cured 2: tin
acrylic resin 3: calcium
1: is about 1 to 3 by volume 4: sodium
2: if too high will result in granularity of the 5: silicon
acrylic Ans: 2
3: if too high will result in excessive shrinkage
4: if too high will have a longer reaction time 21. Sodium N-lauroyl sarcosinate is used in
Ans: 2 dentifrice pastes as a

16: Which portion of the set silicate resto-ration 1. detergent

disintegrates first in oral fluids?
1: Calcium fluoride flux 2. humectant
2: Gel matrix 3. therapeutic agent
3: Silicon dioxide particles 4. Binder
4: Zn3(PO4)2 buffer Ans: 1
5: All portions disintegrate together
Ans: 2
 Dr. Jawad Tariq
3
(KCD)

22: During the casting of noble metal alloys, the 2. Vinyl resins
mold should be held at the burn out 3. Epoxy resins
temperature for at 4. Impression compound
least 5 None of the above
1. 15 minutes Ans: 3
2. 60 minutes
3. 3 hours 28: A dental appliance containing metals or soft
4. 6 hours lining materials, should not be cleaned with
Ans: 2 denture
cleansers containing
1: sodium perborate
23: In general the hygroscopic expansion of 2. soap
gypsum investments will be higher if they 3. hypochlorites
contain 4. salt
1: coarser silica particles and alpha hemihydrate 5. none of the above
2. liner silica particles and beta hemi hydrate Ans:3
3. coarser silica particles and beta hemihydrates
4. finer silica particles and alpha hemihydrate 29: A dental restoration may be tarnished
Ans: 4 because of
1. deposition of calculus
24: The cement capable of forming a chemical 2. surface discoloration
bond with tooth structure is 3. formation of oxides or sulfides
I: reinforced zinc oxide eugenol cement. 4. deposition of pigment producing bacteria
2. silicophosphate cement 5. all of the above
3. polycarboxylate cement Ans: 5
4 composite resin cement
Ans: 3 30: An agar hydrocolloid impression should
never be removed from the mouth by a teasing
25: Quartz in dental porcelain acts as a or weaving
1. binder method because this can result in distortion of
2. frit the impression.
3. opacifier 1: Both the statement and reason are true
4. Strengthener 2. The statement is true but the reason is false
Ans: 4 3. The statement is false but the reason is true
4: Both the statement and reason are false
26: The principal strengthening phaseof Ans: 1
Cerestore, an injection molded ceramic
material, are 31: The curing rate of most of the elastomeric
1. aluminium oxide and silicon oxide impression materials can be accelerated by
2. magnesium silicate and beta-aluminium 1: mixing on a chilled, dry glass slab
3. alpha-alumina and magnesium aluminate 2. the addition of thinners
Spinel 3 the addition of a drop of water during mixing
4. none of the above 4. mixing at a low room temperature
Ans: 3 5- none of the above
Ans:3
27: Which of the following resins may be
classified as thermosetting? 32: The principal hardener in noble metal
1. Polystyrenes casting alloys is
 Dr. Jawad Tariq
4
(KCD)

1. brass 1. Chemical adhesion to tooth structure is never

2. iron possible
3. silver 2. Acid etching of enamel produces chemical
4. copper adhesion
5. Platinum 3. Resins exhibit chemical adhesive properties
Ans: 4 to hard tooth structure
4. Materials containing fluoride will show
33: The color of which of the following metals is chemical adhesion to enamel
not white or one of the shades of white? 5. Polycarboxylate cements demonstrate
1: Nickel chemical adhesion
2. Tin Ans: 5
3. Aluminium
4. Zinc 38. When softening impression compound in a
5. None of the above water bath, the mass is kneaded with fingers in
Ans:5 order to
1. Obtain uniform plasticity throughout the
34: Which of the following may result in the mass
expansion of an amalgam restoration made 2. Remove incorporated water
with zinc free 3. Release all undesirable stresses
alloys? 4. Increase flow
1. Moisture contamination during conden- 5. Prevent the plasticizer from leaching out
sation Ans: 1
2. High alloy/mercury ratio
3. Marginal leakage 39: Self-cured and heat-cured acrylic res-ins are
4. Insufficient trituration most similar in respect of which of the following
5. All of the above properties?
Ans: 4 1: Color stability
2. Curing shrinkage
35: Resins which soften when heated and set on 3. Transverse strength
cooling, are termed 4. Internal porosity
1:thermoset resins 5. Hardness
2. irreversible resins Ans: 5
3 thermoplastic resins
4. etastoMeric resins 40: During the setting of gypsum, the mass
5. thermosetting resins thickens and then hardens into needle like
Ans: 3 clusters called
1. spicules
36: A compressive stress is always accompanied 2. crystallites
by 3. spherulites
1. an elastic strain 4. Satellites
2. a compressive strain Ans: 3
3: a shearing strain
4: a tensile strain 41: Which of the following colloidal solutions
Ans: 2 can be termed aerosol?
1. Liquid in solid
37. Which of the following is true about 2. Gas in liquid
chemical adhesion of restorative materials? 3. Liquid in air
4. Solid in liquid
 Dr. Jawad Tariq
5
(KCD)

5. None of the above 47: Strength in gypsum investments is provided

Ans: 3 by
1. quartz
42: Which of the following is required for the 2. dental stone
crosslinking of condensation sili-cone 3. Indymile and cristobalite together
elastomers? 4. silica
1: Platinum oxide 5. Borax
2. Tin octoate Ans: 2
3. Copper dioxide
4. Calcium sulfate 48: Internal porosity is most likely to occur in
5. Lead which portion of a denture?
Ans: 2 1. On the surface
2. In those portions located near the flask
43: Fins or spines may be produced on a casting periphery
because of 3. In the centre of a thick portion
1. cracks in the investment 4. In the portions having less thickness of resin
2. too rapid heating of the mold Ans: 3
3. steam production which causes the walls of
the mold to flake off 49: Invariant transformation is a property of
4. all of the above 1. eutectic and peritectic alloys and solid
Ans: 4 solutions
2. peritectic alloys only
44: Zinc phosphate cement powder contains all 3. eutectic alloys only
of the following, except 4. eutectic and peritectic alloys
1. zinc oxide 5. solid solutions only
2. magnesium oxide Ans: 4
3. bismuth oxide
4. aluminium phosphate 50: The chemical used as a catalyst for the
5. none of the above cross-linking of addition silicones is
Ans: 4 1. sulfinic acid
2 copper Oxide
45: Dental porcelains are manufactured by a 3: platinum salt
process, termed 4. titanium dioxide
1. frilling 5. palladium salt
2. fusing Ans: 3
3. vulcanizing 51: Compared to the unfilled direct-filling resins
4. Sintering cured by the benzoyl peroxide-tertiary amine
Ans: 1 system,
those cured by the sulfinate system, have
46: The structure of Dicor, a castable glass 1:poor color stability and are more sensitive to
ceramic. is essentially composed of inhibition by 02
1. crystalline mica particles 2. poor color stability and are less sensitive to
2. microscopic silica particles inhibition by O2
3. interlocking apatite crystals 3. better color stability and we more sensitive
4. microcrystalline quartz particles to inhibition by O2
Ans: 1 4. better co/or stability and are less sensitive to
inhibition by O2
Ans: 4
 Dr. Jawad Tariq
6
(KCD)

57: Alteration of the base paste - catalyst paste

52: Which of the following is a thermo-plastic ratio is not an effective method of altering the
material? curing
1: Impression compound rate of polysulphide materials, primarily
2:. Acrylic resin because
3. Dental porcelain 1. the alteration is totally unpredictable
4. Plaster 2. this is not economical as a portion of paste
5. Zinc oxide - eugenol paste will be unused
Ans: 1 3. this does not alter the setting time
4. the mechanical properties are adversely
53: The safest method of removal of the affected
compound impression from the stone cast is, to Ans: 4
immerse it in
1. warm water 58: Amongst the following alloy forming
2. cold water elements, the highest melting point of 3700°C is
3. water at mouth temperature of
4. boiling water 1 carbon
Ans: 1 2. zinc
3. antimony
54: The setting expansion of gypsum bonded 4. Cobalt
investments is approximately Ans: 1
1. less than 0.1%
2. 0.1% to 0.5% 59: Stainless steel can be stabilized by the
3. 0.5% to 1.5% addition of
4. 1.1% to 3.5% 1: Titanium
5. 1.0% to 10% 2: Carbon
Ans: 2 3: Cobalt
4: Lead
55: Repeated stressing of agar gel will Ans: 1
1. increase its stiffness 60: Which of the following designates the finest
2. make it more brittle abrasive?
3. increase the likelihood of fracture 1: 0
4. all of the above 2: 00
Ans: 4 3: 000
4: 0000
56: Which of the following substances is often Ans: 4
added to reversible hydrocolloids to increase
strength 61: When curing dentures, before Packing resin
and viscosity? in the mold, the mold surface must be coated
l: 2% potassium sulfate with a
2. Borax separating agent, so that
3- Glutaraldehyde 1. trial packing can be accomplished
4. Thymol 2. deflasking is done easily
5. Glycol 3. the dissolved polymer and free monomer are
Ans: 2 prevented from soaking into the mold surface
4. rising steam from the water in gypsum does
not affect the polymerization of resin
Ans: 3
 Dr. Jawad Tariq
7
(KCD)

67: Nickel when added to base metal alloys,

62: The following common metals used in increases its
dentistry, the lowest melting point of 960°C is 1. strength
of 2. hardness and fusion temperature
1. platinum 3. modulus of elasticity
2. chromium 4. Ductility
3. cobalt Ans: 4
4. palladium
5. Silver 68: An example of a resin polymerizing by
Ans: 5 condensation reaction is
1. Bakelite
63: The main ingredient of inlay casting wax is 2. epoxy resins
1. dammar resin 3. poly (methyl methacrylate)
2. guttapercha 4. Polycarbonate
3. carnauba wax Ans: 1
4. paraffin wax
5. candelilla wax 69: The activating compounds for visible light
Ans: 4 cured resins are, usually
1. peroxide and quinolines
64: Which of the following is a disadvantage of 2. camphoroquinone and biacetyl
electroformed dies? 3 aromatic amines and methyl meth-acrytate
1. They have low strength 4. biacelyl and quinolines
2. They have poor detail reproduction 5: aromatic amines and camphoroquinone
3. They have poor abrasion resistance Ans: 2
4. They require long time for fabrication
5. None of the above 70: Marginal breakdown of a dental amal-gam
Ans: 4 restoration is usually related to its
1. creep rate
65: An Increase in which of the following would 2. tensile strength
result in increased localised shrinkage porosity 3. coefficient of thermal expansion
of a 4. Malleability
casting? Ans: 1
1. Sprue length
2. Melt temperature 71: When casting noble metal alloys, which of
3 Mold temperature the following shrinkages is not of any
4 Sprue thickness consequence
Ans: 1 1. Thermal contraction of the metal which
occurs when it cools down to room
66: The effectiveness of cement thermal temperature
insulating bases under restorations depends 2. Thermal contraction of the liquid metal
primarily on their between the temperature to which it is heated
1: pH and the
2 composition liquidus temperature
3. setting reaction 3. The contraction of the metal inherent in its
4. Thickness change from the liquid in solid state
Ans:4 4. All of the above
Ans: 2
 Dr. Jawad Tariq
8
(KCD)

72: Which of the following is true regarding the 77: A chemical substance which can act as a
synthetic resins? retarder in plaster is
1. The physical properties of a polymer are not 1. 5% sodium sulfate
affected by temperature 2. potassium tartarate
2. Complex side chains in the monomer 3. potassium sulfate
molecule generally produce a strong resin 4. potassium acetate
3. Cross-linking of a polymer does not affect its 5. sodium chloride
strength Ans: 4
4. The lower the molecular weight of the 78: The advantage of sell-cured resins over heat
polymer, the lower will be its softening cured resins for the repair of acrylic resin
temperature dentures is
5. None of the above I. warpage of the denture is less likely
Ans: 4 2. higher strength
3. repair can be safely carried out inside the
73: Light cured composite resins are superior to mouth
other resin systems, as 4: Less rapid increase in creep rate with
1. the dentist has complete control over the Ans: 1
working time
2. these resins have high strength 79: Which of the following substances has the
3. these resins have no polymerization least wettability ?
shrinkage 1. Teflon
4. these resins have superior esthetics 2. Gold
Ans: 1 3. Gypsum
4. Wood
74: Dental amalgam alloys are predominantly 5. Amalgam
1. silver and tin Ans: 1
2. tin and copper
3. copper and zinc 80: An example of a condensation
4. zinc and silver polymerization resin is
Ans: 1 1. Vulcanite
2. Bakelite
75: Model cement is commonly known as 3. cyanoacrylate
1. zinc phosphate cement 4. Vinyl
2. inlay casting wax Ans: 2
3. corrective wax
4. sticky wax 81: The setting reaction of plaster is based on
5. boxing wax 1. flocculation
Ans: 4 2. precipitation
3. coagulation
76: All of the following may be used as retarders 4. gelation
of gypsum setting time, except 5. Induction
1. calcium citrate Ans: 2
2. potassium borate
3. dried blood 82: A material similar to the zinc oxide-eugenol
4. syngenite reaction product can be formed if zinc oxide is
5. none of the above reacted
Ans: 4 with
1. carboxylic acid
 Dr. Jawad Tariq
9
(KCD)

2. methyl guaiacol 3. high thermal conductivity

3. ortho ethoxybenzoic acid 4. malleability and ductility
4. any of the above 5. cohesion at room temperature
Ans: 4 Ans: 3

83: All of the following statements are true for 88: Loss of water by evaporation from the
poly methyl methacrylate resins, except that, it surface of a hydrocolloid gel, is termed
1. will soften at 125°C 1. imbibition
2. exhibits a tendency to take up water 2. memory
3. is chemically stable to heat 3. hysteresis
4. can be molded as a thermoplastic material at 4. syneresis
room temperature 5. Diapedesis
5. is soluble in acetone Ans: 4
Ans: 4
89: The principal deterrent to the use of
84: When casting gold alloys, vacuum investing synthetic resins as restorative materials, is their
of the wax pattern, results in 1. complicated manipulation technique
1. smoother castings 2. opacity
2. decreased porosity of the investment 3. technique sensitivity
3. better detail reproduction 4. high water solubility
4. all of the above 5. poor dimensional stability
5. none of the above Ans: 5
Ans: 4
90: Trituration is the process of
85: Which of the following cement mixes, 1. tightly packing the cavity with amalgam
prepared with the correct P/L ratio, would 2. squeezing out mercury from the amalgam
appear to be most mix
viscous? 3. mixing an amalgam alloy with mercury
1:. Zinc.oxide-EBA 4. powdering the amalgam alloy
2. Zinc phosphate Ans: 3
3. Glass ionomer
4. Silicophosphate 91: Type V dental stone has
5. Polycarboxylate 1. high strength, high expansion
Ans: 5 2. high strength. low expansion
3. low strength, low expansion
86: The amount of chromium in stainless steel 4. low strength, high expansion
should be more than Ans:1
1. 52%
2. 2.5%
3: 38%
4: 11%
Ans: 4 92: Which of the following statements is
incorrect regarding the putty silicones?
87: Direct filling gold offers all of the following 1. They have very low viscosity
advantages for its use in restorative dentistry, 2. They are highly filled
except 3. They are usually used as tray material
1. resistance to abrasion 4. All of the above
2. resistance to corrosion 5. None of the above
 Dr. Jawad Tariq
10
(KCD)

Ans: 1 4: release of stresses due to memory

phenomenon
93: Polymers utilizing chemical activation to Ans: 1
generate tree radicals from benzoyl peroxide
are known as 98: The normal setting expansion sum
1. cross-linked polymers investments Is
2. condensation polymers 1: 0.5%
3: polymerization polymers 2: 0.1%
4. self-curing polymers 3: 1.5%
5. plasticized polymers 4: 1.2%
Ans: 4 Ans: 1

94: Which of the following is the most 99: The strength and stiffness of poly (methyl
important mechanical property when a base methacrylate) resin dentures will be more?
metal cast partial 1. following water sorption
denture clasp is adjusted? 2. after finishing and polishing, because the
1. Elastic limit release of processing stresses
2. Compressive strength 3. in the bulkier portions of the denture
3. Elongation 4. all of the above
4 Tensile strength 5. none of the above
5. Hardness Ans: 3
Ans: 3
100: A metal which is liquid at room
95: Heating a gypsum cast above 90°C will temperature is
1. increase its strength 1. hydrogen
2. remove the water of crystallization 2. helium
3. liberate sulfur dioxide gas 3. iridium
4. eliminate excess gauging water 4. mercury
5: cause expansion 5. Selenium
Ans: 2 Ans: 4
101: Which of the following Is true regarding
96: The temperature dependent distortion in an the use of flux for meltingng noble metal alloys?
impression compound arising from the relief of 1: It is added when the alloy has completely
stresses, is known as melted
1. permanent deformation 2. It is used only with old metal
2. relaxation 3. It is used only with new metal
3. slack 4. It is added before melting the alloy
4, creep Ans:1
5. Slump
Ans: 2 102: The water content of most liquids, for zinc
phosphate cements, is?
97: With regard to reversible hydrocollolds, 1: 15 ± 3%
hysteresis is the 2: 33 ± 5%
1: lag between the gelation and the liquefaction 3. 50 ± 5%
temperature 4. 66 ± 10%
2. difference between Syneresis and imbibition Ans: 2
3. difference in dimensional change which
occurs before and alter gelation
 Dr. Jawad Tariq
11
(KCD)

103: Addition of manganese oxide would give 4. nickel

which shade to porcelain? 5. Iron
1: Blue Ans:1
2. Grayish white
3: Layender 109: Alginate Impression materials datriorate
4. Green rapidly at elevated temperatures, probably due
Ans: 3 to
depolymerization of the alginate constituent?
104: The material of choice for root form dental 1: Both the statement and reason ere correct
implants is 2'.The statement is correct but reason is not
1: cobalt - chromium - molybdenum alloys correct
2. stainless steel 3. The statement is not correct but the reason is
3. ceramics correct '
4. titanium 4. Both the statement and reason are incorrect
5. tantalum-zirconium-carbon alloys Ans: 2
Ans: 4

105: The final product formed by the

polymerization of a phenol formaldehyde rosin. 110: Patients dislike the odor and taste of which
'Bakelite', is Impression material?
termed 1: Polysullides
1:mers 2. Polyethers
2. essole 3. Alginates
3. densite 4. Addition silicones
4. resole 5. None of the above
5: resite Ans: 1
Ans: 5
106: Commercial denture cleansers which 111: . Which of the following materials would
liberate nascent oxygen, clean dentures by have the least change in dimension because of
1:dissolving organic debris changes in
2. bactericidal action mouth temperature?
3. chelating action 1: Acrylic resin
4: MechanicaI action 2. Gold inlay
Ans: 4 3. Composite resin
4. Amalgam
107: The principal corrosion product of dental 5: Silicate cement
gold alloys that contain silver, is? Ans: 5
1: silver chloride
2: silver sulfide 112: If porcelain is to be fused to metal, which
3. hydrogen sulfide of the following properties of porcelain and
4. silver dioxide metal should
Ans: 2 be similar?
1: Color
108: In noble metal casting alloys, platinum may 2: coefficient of thermal expansion
be substituted by the 3. Modulus of rupture
1: palladium 4. Young's modulus
2. carbon 5. Compressive strength
3. gallium Ans: 2
 Dr. Jawad Tariq
12
(KCD)

3. dry strength
113: The strongest phase in dental amalgam is? 4. apparent strength
1: gamma Ans: 1
2: beta 1
3: gamma 1 119: Which of the following would retard the
4: alpha 2 setting reaction of zinc oxide - eugenol?
5: gamma 2 1: Rosin
Ans: 1 2. High humidity
3. Glacial acetic acid
114: The primary corrosion products of 4. Primary alcohols
amalgam are? 5: None of the above
1: silver chloride or fluoride Ans: 5
2: copper sulfates
3: oxides and chlorides of tin 120: The cross linking reaction of poly-sulfide
4. zinc and silver dioxide elastomers can be made more effective by the
Ans: 3 addition of
a small amount of
1: tin
115: Zinc oxide eugenol pastes should not be 2. lead
used as? 3: sulfur
1: a surgical dressing 4. fluoride
2. a permanent filling material 5. Platinum
3. a bite registration paste Ans: 3
4. a temporary relining material for dentures
5. an impression material 121: The sprue former should he attached to
Ans: 2 the wax pattern?
1: on a flat surface
116: Creep is associated with? 2. in an area where the anatomy is not critical
1: flow of molten alloy along the sprue 3. at the thinnest point
2. contact angle measurement 4. on any proximal surface
3. slump occurring in porcelain glasses 5: at the point of greatest bulk
4: marginal breakdcwn of amalgam Ans: 5
5. expansion of the investment mold
Ans: 4 122: The film thickness for a luting cement
should not be greater than?
117: Which of the following hardness tests uses 1: 100 micrometer
a hardened steel ball indenting tool? 2: 1.5 um
1: Rockwell hardness test 3: 25 um
2. Vickers hardness test 4: 500 um
3: Brinell hardness test Ans: 3
4. Knoop hardness test
5. Bierbaum hardness test 123: In PFM (porcelain fused to metal)
Ans: 3 restorations, the porcelain bonds to metal by?
1: mechanical bonding
118: The green strength of a gypsum product 2. chemical bonding
refers to its? 3. compressive bonding
1: wet strength 4: a11 of the above
2. actual strength Ans: 4
 Dr. Jawad Tariq
13
(KCD)

129: Methyl methacrylate based denture base

124: What should be the relation of the resins contain all of the following. Except?
modulus of elasticity of a cement base and that 1: glycol dimethacrylate
of the 2. dibutyl phthalate
restorative material? 3. benzoyl peroxide
1: There is no relation at all 4. pure methyl methacrylate
2. The restorative material must have a higher 5-: sodium silicate
modulus Ans: 5
3. The cement base must have a higher
modulus 130: When mixing dental stone, if the water-
4-The modulus must be equal powder ratio is increased, the?
Ans: 4 1: compressive strength is increased
2. surface hardness is increased
125: The property of flow is most important in? 3. setting time is decreased
1: waxes 4, setting expansion is decreased
2. zinc oxide - eugenol cements Ans:4
3. investments
4. gold alloys 131: What is the name given to the technique in
Ans: 1 which acrylic resin is softened by heat and
introduced
126: When liquefying agar hydrocolloid gel. it into flasks under pressure?
should not be boiled for more than 10 minutes, 1: Fluid resin technique
as this 2. Vacuum molding technique
may result in? 3. Compression molding technique
1: decrease in strength 4. Pressure technique
2. incorporation of undesirable stresses 5: Injection molding technique
3. leaching out of the plasticizer Ans: 5
4. all of the above
5: none of the above 132: Following casting, the gypsum mold is
Ans: 5 quenched in water when the button emits a
1: dull red glow
127: An elastomeric impression will be more 2. cherry red glow
accurate if it is? 3. light orange glow
1: removed as soon as it sets 4. dull grey glow
2. removed after 8-10 minuted Ans:1
3: allowed to remain in the mouth for a longer
time 133: Which ingredient is added to Inlay wax to
4. time in mouth is not critical for accuracy improve its smoothness during molding ?
Ans:3 1: Paraffin wax
2. Gum dammar
128: An alloy is a solid mixture of? 3. Candelilla wax
1: two or more metals, one at which it mercury 4. Carnauba wax
2. three or more metals. one of which is gold 5. Ceresin
3: two or more metals Ans: 2
4. two or more metals, one of which is amalgam
Ans: 3 134: When making an impression, the
impression compound should be placed in the
patient's mouth at
 Dr. Jawad Tariq
14
(KCD)

1: 75°C metals are soluble in each other in the solid

2. 100.4°C state, is termed?
3. 37°C 1: intermetallic compound
4: 45°C 2. eutectic alloy
5: 60°C 3: solid solution
Ans: 4 4. peritectic alloy
Ans:3
135: Sometimes a die larger than the prepared
tooth is desired, to aid in compensating for the . 140: The primary reason why conventional
1: casting shrinkage of the alloy porcelain alone is not used as a crown and
2. dimensional change of the impression bridge restorative
3. warpage of the wax pattern material, is its?
4. expansion of the mold 1: microleakage
Ans:1 2,. lack of strength
3. complicated fabrication technique
136: The phosphate investment clinging to base 4. extreme hardness
metal castings is cleaned by? 5. lack of ductility
1: dipping in cold hydrofluoric acid Ans: 2
2. grinding with a bur or stone
3. heating in hydrochloric or sulfuric acid 141: Sand is used for the polishing of?
4: sand blasting 1: noble metal alloys
Ans:4 2. amalgam restorations
3. resin dentures
137: The high initial solubility of silicate 4: base metal alloys
cements is attributed to the? Ans:4
1:acid-base nature of the setting reaction
2: rather long time required for the setting 142: Strain hardening of a metal would result in
reaction to go to completion - an increase in its?
3. low coefficient of thermal expansion of the 1: elastic modulus
cement 2: ductility
4. high water content of the cement liquid 3. resistance to corrosion
Ans: 2 4: strength
Ans: 4
138: During the trial packing of resin into a
mold, the excess which flows into the land 143: Fillers are added in composite resins to?
surrounding the 1: inhibit deformation of the matrix
mold space. is termed? 2. reduce the coefficient of thermal expansion
1: sprinkle of the resin matrix
2. sheet 3: both of the above
3. rosin 4. none of the above
4. trim Ans:3
5: flash
Ans:5 144: The creep rate of an amalgam restoration
decreases when the?
139: An alloy in which the atoms of two metals 1: mix is overtriturated
intermingle randomly in a common space 2. time lag between trituration and
lattice, and the condensation is more
3. mercury content of the mix is increased
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4. mix is slightly undertriturated 149: When restoring a cavity with direct filling
5: condensation pressure is increased gold, transverse strength and density would be
Ans: 5 greater,
when?
145: Which of the following statements is not 1: combination of mat gold and electrolytic gold
true regarding addition polymerization are used
reaction? 2. powdered gold is used alone
1: There is no change in the composition 3. gold foil is used alone
2:Byproducts are formed 4: combination of mat gold and gold toil are
3. The reaction is exothermic used
4. The reaction can be activated by UV light Ans:4
5. None of the above
Ans:2 150: When curing dentures, the surface or
subsurface porosities occurring with the fluid
146: Which of the following resins are bio- resin
degradable? technique, are commonly due to?
1: Cyanoacrylates 1: lack of adequate pressure during
2. Polyurethanes polymerization
3. Polycarbonates 2: failure to expel air inclusions incorporated
4. Polystyrenes during pouring of the resin
5. Epoxy resins 3. lack of homogeneity in the dough or gel
Ans:1 4. a definite lack of dough or gel in the mold at
the time of final closure
147: Microfilled composites contain filler Ans:2
particles with diameters in the range of ?
1: 4 - 20 um 151: Of the following, the most ductile metal is?
2: 0.04 - 0.06 um 1: silver
3: 20 - 80 um 2. palladium
4: 0.8 - 6 um 3.platinum
Ans: 2 4. Gold
Ans: 4
148: Poly (methyl methacrylate) resin despite
having a high volumetric curing shrinkage, can 152: A desirable characteristic of Type ll (Type
be used to B) inlay waxes used in the direct technique is
produce clinically satisfactory dentures that, they
because? should?
1: shrinkage will be distributed uniformly over 1: have a color which matches that of the tooth
all surfaces of the denture 2: have a flow of less than 1% at 37°C
2. when packed under pressure the shrinkage 3. have a flow of at least 50% at 45`C
will be reduced to acceptable levels 4. have a high coefficient of thermal expansion
3. the separating media used, reduces the Ans:2
shrinkage
4. the heat employed in polymerization reduce 153: Which of the following methods of
the shrinkage manufacturing results in the hardest type of
Ans:1 dental stone?
1: Calcining gypsum in open vats
2: 'Calcining gypsum in a 30% solution of
calcium chloride
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3. Direct mining from the earth Ans:1

4. Calcining gypsum in a pressure pot under 20
lbs/inch2 pressure 159: A buffering agent present in the liquid for
Ans: 2 silicate cements is?
1: aluminium phosphate
154: The strength of zinc oxide - eugenol 2. silicon dioxide
cements can be substantially increased by? 3. aluminium trioxide
1: increasing the spatulation lime 4. silicon trioxide
2: the addition of orthoethoxy benzoic acid 5. calcium fluorophosphates
3. using a lower powder/liquid ratio Ans: 1
4. addition of a drop of water to the mix 160: What is the maximum permissible flow of
Ans:2 impression compound (Type 1) at mouth
temperature?
155: Color matching should be done under two 1: 1%
or more different light sources because of the 2. 3%
phenomenon of? 3: 16%
1: radiance 4. 18%
2. Fluorescence 5. 40%
3: metamerisrn Ans: 3
4. eye fatigue
5. Munsell effect 161: The casting ring with the mold is placed in
Ans: 3 the furnace with the sprue hole
1: down
156: How many calories of heat are required to 2. at an angle of 45°
vaporize 1 gm of water at 100°C? 3. up
1: 1080 4. Sideways
2. 270 Ans: 1
3. 860
4: 540 162: The gelation temperature of colloid
Ans:4 Impression material agar hydrocolloid should be
1 far below the oral temperature
157: Zinc oxide-eugenol paste is better than 2: 37.45*c
wax for making interocclusal records primarily 3: 10*C higher than mouth temperature
because it 4. 45-60*C
1: can be easily removed from undercuts 5. above plaster setting temperature
2. is more stable dimensionally Ans: 2
3. records surface detail better
4: offers no resistance to closing of the 163: When mixing self-curing resins, decreasing
mandible the temperature of the mixing jar, would?
5: requires lesser time to set 1: prolong the initiation period and dough
Ans: 4 forming time
2. prolong the initiation period and shorten the
158: Which of the following materials provides dough forming time
body and strength to reversible hydrocollolds ? 3; shorten the initiation period and prolong the
1: Borax dough forming time
2. Agar agar 4. shorten the initiation period and dough
3. Water forming time
4. Lead dioxide Ans: 1
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3. Change in ratio of the two pastes

164: In the polymerization of two monomers. if 4. Mixing time
identical monomer units occur in relatively long 5. Amount of calcium chloride
sequences along the main polymer chain, the Ans:1
type of copolymer formed, is termed?
1: selective 169: Silicate cement restorations should never
2: block be used?
3. random 1: adjacent to caries susceptible areas
4. bridge 2. in esthetically critical areas
5. Graft 3: in mouth breathers
Ans: 2 4. in persons with bruxismal tendencies
Ans: 3
165: When processing a mandibular denture
from heat-curing resin by compression molding, 170: A dental amalgam restoration (lathe cut
porosities alloy) will have higher strength if?
due to the boiling of monomer are most likely 1: The mix is slightly overtriturated
to occur in the? 2: higher condensation pressure is used
1: buccal flange area 3. the mix is undertriturated
2. region around the necks of teeth 4. the mix has a high mercury to alloy ratio
3. anterior region of the lingual flange Ans: 2
4: posterior lingual flange area
5. region of labial, flange 171: The best method of avoiding air bubbles in
Ans: 4 a gypsum mold is to?
1: use vacuum investing technique
166: Any of the following may occur with agar 2. use a mechanical mixer
based impression material excep? 3. vibrate the mix before and after mixing
1: imbibition 4. vibrate the invested wax pattern on a
2: recrystallization vibrator
3. Hysteresis Ans:1
4: syneresis
5. none of the above 172: Impression compound should flow easily
Ans:2 to?
1: duplicate undercuts
167: All of the following are inorganic phases 2. ensure uniform cooling
used in composite resins, except? 3. ensure that deformation is completely elastic
1: quartz 4. avoid incorporation of stresses
2. borosilicate 5: record surface detail accurately
3. lithium aluminium silicate ` Ans: 5
4: BIS-GMA resin 173: All of the following abrasives may he used
5. none of the above in dentifrices, except?
Ans: 4 1: calcium carbonate
2: sodium lauroyl sulfate
3. tricalcium phosphate
168: Which of the following least influences the 4. magnesium oxide
setting time of zinc oxide-eugenol impression 5. calcium pyrophosphate
paste? Ans:2
1: Rosin content
2. Presence of moisture
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174: A compound used as an activator in UV 3. for constructing impression trays

light cured resins is? 4. as filling materials
1: camphoroquinone 5. none of the above
2: alkyl benzoin ether Ans: 2
3. heat
4. diketone 180: Gold casting alloys can be age hardened by
5. tertiary amine heating at?
Ans: 2 1: 500°C for 10 min followed by slow cooling to
room temperature
175: The primary advantage of microwave 2: 300°C for 1 hour followed by slow cooling to
polymerization of resins over conventional hot room temperature
water 3: 750-900°C for 5-10 min and then quenching
polymerization is that, microwave curing? in water
1: decreases porosity 4: 200-450°C for 15-30 min and then quenching
2: is cleaner and faster in water
3. produces vastly superior strength and Ans: 4
fracture resistance of resins
4. produces superior fit
Ans: 2 181: When die spacers are used, the gypsum die
Is coated with resin?
176: Pyroplastic flow of porcelain is decreased 1: only on the enamel surfaces
by the addition of? 2: to within 0.5 mm of the margin
1: soda form of feldspar 3. Upto 1.0mm cervical to the gingival finiish
2. boric acid line
3: potash form of feldspar 4. onto the exposed portion of the tooth on the
4: quartz die
Ans: 3 Ans:2

177: Glass ionomer cements are primarily used 182: Which of the following components of
for? alginate impression material may be a possible
1: temporary restorations health hazard?
2: restoring eroded areas 1: Alginic acid
3. pulp capping 2. Triethanol amine
4. thermal insulating bases 3:Silica
Ans:2 4: Anise
5. None of the above
178: The chief ingredient of an irreversible Ans: 3
hydrocoiloid impression material is?
1: sodium alginate 183: Butyl rubber dissolved in chloroform is
2. potassium oxalate 3: borax used as a tray adhesive, when making an
4: calcium sulfate impression with
5. zinc oxide 1: agar hydrocolloids
Ans: 1 2. addition silicones
3: polysullides
179: Methyl methacrytate resins are used for all 4. condensation silicones
of the following, except? 5. Alginates
1: for the manulacture of teeth Ans: 3
2: as impression materials
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184: Pyroplastic flow of dental porcelain? 4: filler, resin binder, coupling agent
1: will be high if the soda/potash ratio is less Ans:4
2. is determined by the soda form of feldspar
3: is determined by the potash form of feldspar 190: An example of a eutectic alloy system is,
4. is determined by the quartz form silver and?
5. should be high 1: copper
Ans: 3 2. tin
3. platinum
185: When cristobalite is heated to 300°C, it? 4. Gold
1: exhibits slight shrinkage Ans:1
2: changes from beta to alpha form
3: decreases in density 191: Biological tests in which the material is
4. inverts from a high form to a low form evaluated in experimental animals under
Ans: 3 conditions that
simulate the clinical use of the material, are
186: The sol to gel transformation in the case of termed?
reversible hydrocolloids, is a function of ? 1: Level I tests
1: time 2. Level II tests
2. water content 3. Level III tests
3. potassium sulfate concentration 4. Level IV tests
4. silica content Ans:2
5: temperature
Ans: 5 192: The first manifestation that plaster has
187: A high mercury to alloy ratio in dental deteriorated from storage in a humid
amalgam will result in? environment is?
1: more of the gamma phase being available 1: decrease in hardness
2: more matrix material being formed 2. a decrease in the setting time
3. high strength 3. a change in color
4. low expansion 4. an increase in porosity
5. high corrosion resistance Ans: 2
Ans:2
193: The mixing of which of the following non-
188: Which of the following characteristics of a aqueous elastomeric impression materials is
dental resin does not play a major role in different
determining its from that of others?
physical properties? 1: Addition silicones
1: Degree of polymerization 2. Condensation silicones
2. Chain structure 3. Polysulfides
3. Degree of crosslinking 4: Putty silicones
4: Solubility 5. None of the above
5. Molecular weight distribution Ans:4
Ans: 4
194: Polycarboxylate cement powder contains
189: A composite, restorative material all of the following, except?
essentially contains? 1: stannic oxide and stannous fluoride
1: inorganic filler, organic filler, coupling agent 2. magnesium oxide
2. polymerizing resin, catalyst, pigment 3: potash alum
3. resin matrix, activator, filler 4. polyacrylic acid
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5. zinc oxide Ans: 2

Ans: 3
200: Which of the following forms of iron are
195: The principal requisite for a die stone is? soft and ductile?
1: high setting expansion 1: Cementite and martensite
2. low porosity 2. Martensite and ferrite
3. high flow 3. Ferrite and austenite
4: great strength and hardness 4. Austenite and cementite
5. controlled setting time Ans: 3
Ans: 4
201: Type II noble metal alloys are appropriate
196: Resins find use In dentistry as? for casting ?
1: denture base materials 1: pontics, full crowns. thick 3/4 crowns, inlays
2. maxillofacial prosthetic materials subject to moderate stresses
3. denture relining materials 2. full crowns, ponlics, inlays, partial frame-
4: All of the above works
5. none of the above 3. small inlays, long span budges, saddle bars
Ans: 4 4. short span bridges. 3/4 crowns. thin cast
backing abutments
Ans: 1
197: When restoring the posterior teeth in a
child patient with amalgam, if it is difficult to 202: A method of imparting hardening heat
keep the treatment to dental gold alloys, is to?
region dry, it is preferable to? 1: Heat the alloy to 450°C and gradually cool to
1: use zinc free alloys 225°C in half an hour
2. fill the cavity in small increments 2. heat the alloy to 700*C and quench in cold
3. use automatic condensers water
4. all of the above 3. heat the alloy to 500-C and bench cool for 2
Ans:1 days
4. heat the alloy to 200°C, hold for 20 minutes
198: The ability of a direct filled gold restoration and then further heat to 600°C and quench in
to withstand the stresses present can be best cold water
explained Ans: 1
by which physical characteristic of gold?
1: Dendritic microstructure 203: Strength of an amalgam restoration will be
2. Transverse strength of about 39,000 psi more if?
3. Apparent density of about 15 gm/cm3 1: a slight excess of mercury is left in the
4. Knoop hardness number of 60 to 75 restoration
Ans: 2 2. lower condensation pressures are applied
3: porosity is less
199: prior to investing the casting ring is lined 4. trituration time is increased
with asbestos to? 5. none of the above
1: prevent sliding of the investment mold Ans: 3
2. prevent confinement of mold expansion
3. permit easy retrieval of the casting 204: A wrought metal?
4. prevent cracking of the mold 1: is resistant to corrosion or attack by acids
5. reduce the amount of investment required 2: formed by working on a cast metal
for investing 3. formed by pouring molten metal into a mold
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4 cannot he heat treated 5. Doughy stage

5. none of the above Ans: 5
Ans: 2
205: The most effective method of preventing 210: Which of the following is the first sign of
distortion of the wax pattern is? preset hydration in a gypsum product?
1: by holding the WAX under equal pressure, 1: Prolonged setting time
from all Sides while it solidifies 2. Decreased strength
2: to invest the pattern as soon as possible 3. Increased thermal expansion
3. to dip the die repeatedly in molten wax 4. Increased hygroscopic expansion
4. By adding molten wax In small increments 5: accelerated setting
Ans: 2 Ans: 5

206: The ability of an alloy to withstand 211: The setting of dental plaster can be
mechanical stresses without permanent accelerated by?
deformation, is 1: mixing with boiling water
reflected by it? 2. increasing the water to powder ratio
1: resilience 3. the addition of borax
2: yield strength 4: rapid vigorous mixing
3: hardness 5. all of the above
4. fatigue resistance Ans: 4
Ans: 2
212: Sublimation is the conversion of ?
207: What should be the optimum thickness of 1: solid directly to gas
rubber base impression materials in a tray ? 2. gas to liquid and then to solid
1: At least 10mm 3. gas directly to liquid
2: 6-8mm 4. solid to liquid and then to gas
3: 2-3mm Ans: 1
4. Less than 1mm
Ans: 3 213: When testing the biocompatibility of
dental materials for evaluation of pulp
208: The liquid for heat-cured acrylic resins reactions, the material
contains all of the following, except ? which is used as negative control is?
1: hydroquinone 1: gold filling
2. methyl methacrylate 2: calcium hydroxide cement
3. glycol dimethacrylate 3. zinc oxide eugenol cement
4: dimethyl-p-toluidine 4. amalgam filling
5. dibutyl phthalate 5. silicate cement
Ans: 4 Ans: 3
214: The modulus of elasticity or Young's
modulus of a materials is indicative of its?
1: rigidity
2. resilience
209: In which stage is the heat-curing resin 3. impact force
material packed into the mold? 4. breaking strength
1: Adhesive stage 5. Malleability
2. Rubbery stage Ans: 1
3. Tacky stage
4: Stringy stage
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215: When mixing plaster, the higher the W/P 220: The polymerization of heat- curing resin Is
ratio the Initiated by the formation of?
1: weaker will be the gypsum product 1: hydrogen bonds
2. longer will be the setting time 2. free redicals
3. lesser will be the setting expension 3. Valance electrons
4: all of the above 4, active atoms
5: none of the above Ans: 2
Ans: 4
221: Equilibrium phase diagrams are useful in
216: A silver electroplating heat solution, will determining the?
contain all of the following, except? 1: solubility of the alloy components at a
1: silver cyanide particular temperature
2. potassium carbonate 2. chemical composition of the alloy at a
3. distilled water particular temperature
4. potassium cyanide 3. melting point and boiling point of an alloy
5. sulfuric acid 4. stability of the alloy at a particular
Ans: 5 temperature
Ans: 2
217: In a casting, subsurface porosity can be
diminished by controlling the? 222: A gold alloy, designated as 750 fine,
1: mold temperature indicates that?
2. sprue length 1: 7.5% of the alloy is pure gold
3. melt temperature 2: the alloy is 20 karat
4. rate at which the molten metal enters the 3: three-fourth of the alloy is pure gold
mold 4: the grain size of the alloy is 75 microns
5. none of the above 5: the alloy has been distilled 750 times
Ans: 4 Ans: 3

218: The working time of polycarboxylete 223: A potentially toxic element in base metal
cement can be prolonged by all of the following, alloys is?
except ? 1: molybdenum
1: using a cool glass slab 2. beryllium
2. cooling the polyacrylic acid liquid in a 3. boron
refrigerator 4. Magnesium
3. cooling the powder in a refrigerate, Ans: 2
4. none of the above
Ans: 2 224: Thermal shrinkage of heat curing resins is,
that shrinkage which occurs?
219: Which of the following it not an ingredient 1: during the polymerization of the resin
of gypsum bonded investments? 2. on cooling, from glass transition temperature
1: Alpha hemihydrate to room temperature
2. Cristobalite 3. on cooling, from boiling point to mouth
3. Carbon temperature
4. Boric acid 4. on cooling, from curing temperature to glass
5. None of the above transition temperature
Ans: 5 Ans: 2
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225: A method of expressing the degree of 1: less than 35%,

polymerization of polymers is by? 2: 10 - 15%
1: average atomic weight 3: more than 60%
2. valence electrons 4. more than 30%
3, stoitiometric ratio Ans: 3
4, number average molecular weight
Ans: 4 231: Incorporation of synthetic resins and ortho
ethoxy benzoic acid into conventional zinc
226: For which of the following cements is oxideeugenol
polyacrylic acid the parent compound? cements will?
1: calcium hydro-oxide cements 1: decrease solubility
2. Copper phosptrate cements 2. increase adhesive capability
3. Glass ionomer cements 3. decrease strength
4. Polycarboxylate cements 4. decrease film thickness
5. Silicophosphate cements Ans: 1
Ans: 3
232: Which of the following terms is different
227: All of the following are problems from the others?
associated with electric annealing of gold 1: Yield strength
pellets, except? 2. Proportional limit
1: the various pellets cannot stick together 3. Elastic limit
2. it is difficult to anneal the appropriate 4. Young's modulus
amount of gold required 5. None of the above
3. air currents may affect the uniformity of Ans: 4
heating
4. there is a greater chance of contamination if 233: The high copper dispersion type amalgam
the gold is not used immediately alloys are characterized by all of the following,
Ans: 1 except?
228: The typical recommended W/P ratio for 1: less marginal breakdown
Type IV stone is? 2. low creep
1: 0.30 to 0.35 3. little or no gamma-2 phase present in set
2. 0.20 to 0.25 amalgam
3. 0.45 to 0.55 4. little or no gamma phase in set amalgam
4. 0.10 to 0.15 5. none of the above
Ans: 2 Ans: 4

229: Impression plaster? 234: The liquid for zinc phosphate cements
1: will produce less mucosal displacement than contains all of the following, except?
alginate 1: sulfuric acid
2. should not be used with an anti-expansion 2. water
solution 3. aluminium phosphate
3. should be poured immediately on removal 4. phosphoric acid
from the mouth without any further treatment Ans: 1
4. is always white in colour
Ans: 1 235: The stone cast should be constructed
within the first 30 minutes of removal of an
230: The percentage of filler (by weight) in elastomeric
conventional composite resins la usually?
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(KCD)

impression from the mouth. This time interval is 4: 2 to 2.6%

not critical for? 5: 5.0% to 7.5%
1: polysullides Ans: 3
2. addition silicones
3. condensation silicones 241: Which of the following is a disadvantage
4. all of the above with polyether impression materials?
5. none of the above 1: Poor elasticity
Ans:2 2. Difficulty in mixing
3. Poor flow
236: Hydroquinone, added to the resin 4. Dimensional instabiiity in the presence of
monomer, acts as? moisture
1: an inhibitor Ans: 4
2. an accelerator
3. a polymerization agent 242: The strain that occurs when a material is
4. a cross-linking agent stressed to its proportional limit is termed?
5. a catalyst 1: resilience
Ans: 1 2. maximum flexibility
3. tensile stress
237: The filler concentration (by weight) in 4. Stress
micro-filled composites is? Ans: 2
1: 10-15%
2: 35-50% 243: All of the following are requisites of a
3: more than 75% dental solder, except?
4: 80-95% 1: resistance to tarnish and corrosion
Ans: 2 2. restricted flow
3. strength equal to that of the work
238: Direct filling powdered gold is normal 4. all of the above
supplied in which form? 5. none of the above
1: Powder enclosed in a capsule of inert Ans: 2
material
2. Pellet containing compressed powder 244: When it is necessary to clean or soak a
3. Loose powder form dental stone cast for a prolonged time, which
4. Powder wrapped in a gold foil type of water
Ans: 4 should be used?
1: Tap water
239: The normal hygroscopic setting expansion 2. Clear slurry water
of gypsum bonded investment is? 3. Distilled water
1: 0.4 - 0.8% 4. Mineral water
2: 0.01 - 0.06% 5. Soap water
3: 1.2 -2.2% Ans: 2
4: 2 - 3%
Ans: 3 245: Thermal diffusion through a material
depends on its thermal conductivity and?
240: The solidification shrinkage of gold alloys Is 1: latent heat of fusion
In the range of? 2: melting point
1: 0.02% to 0.2% 3. thickness
2: 0.5% to 1.0% 4.coefficient of thermal expansion
3: 1.25% to 1.45% 5. invariant transformation point
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(KCD)

Ans: 3 251: Which of the following is not a type of

copolymer?
246: Hydrocolloid impression materials are? 1: Block
1: liquids suspended in liquids 2. Chain transfer
2. solids suspended in liquids 3. Graft
3. solids suspended in solids 4. Random
4. metallic dispersions 5. All of the above are copolymer types
5. none of the above Ans: 2
Ans: 2
252. Fluxes for soldering base metal alloys
247: The various shades of dental porcelain are contain all of the following, except
obtained by the addition of metal oxides. Which 1: sodium pyroborate
of the 2: mica
following metallic oxides is incorrectly matched 3: boric acid
with the shade it gives? 4: silica
1: Nickel oxide - brown Ans: 2
2. Cobalt oxide - lavender
3. Titanium oxide - yellowish brown 253: The average processing shrinkage of a self-
4. Iron oxide - brown curing resin denture is?
5. Copper oxide – green 1: 4.5%
Ans: 2 2: 0.01%
3: 0.006%
248: The best gas for melting an alloy is? 4. 0.25%
1: natural gas Ans: 4
2. hydrogen
3. acetylene 254. The principal difference between heat-
4. helium cured denture base resins and cold-cured resins
5. Propane is the?
Ans: 5 1: absence of initiator in cold-cured resins
2. presence of amine activator in cold-cured
249: Which of the alloying elements decreases resins
the hardness of steel? 3. absence of dibutyl phthalate plasticizer in
1: Nickel cold-cured resins
2. Cobalt 4. absence of initiator in heat-cured resins
3. Manganese 5. basic structure of the resins
4. Carbon Ans: 2
Ans: 2
255. Which of the following non-aqueous
250: Silver added to a solder, does not perform elastomeric Impression materials has the least
which role? shelf-life?
1: Narrows the melting range 1: Condensation
2. Increases flow of the solder 2. Polysullides
3. Acts as a deoxidizer 3. Polyethers
4. Increases adherence of solder to metal 4. Addition silicones
5. None of the above Ans: 1
Ans: 3
256. Vitallium is an alloy of?
1: chromium and cobalt
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2, nickel and chromium 262. The oxidizing agent used in the

3. iron, nickel and chromium polymerization of polysulfide impression
4. nickel and titanium materials is?
Ans: 1 1: lead peroxide
2. tin octate
257. When curing visible light curing resins, the 3. lead octate
light must be held? 4. stannous octate
1: close to but not touching the restoration 5. copper phosphate
2: 1 cm away from the restoration Ans: 1
3. as far away as possible from the restoration
4: touching the restoration 263. Growth of secondary dentin is best
Ans: 1 stimulated by?
1: composite resin cements
258. Direct tilling gold contains? 2. zinc phosphate cements
1: more than 90% pure gold 3. zinc oxide-eugenol cements
2. 70.85 % gold 4. calcium hydroxide cements
3. 99.99% pure gold 5. Carboxylate cements
4. more than 65% gold Ans: 4
Ans: 3
264. Which of the following atomic bonds are
259. Tarnishing of amalgam restorations is due characterized by physical forces?
to the formation of? 1: Ionic bonds
1: silver sulfide 2. Van der Waals bonds
2. tin oxide 3. Metallic bonds
3. silver halide 4. Primary bonds
4. copper sulfide 5. Covalent bonds
Ans: 1 Ans: 2

260. Which of the following terms can aptly 265. A reusable impression material is?
describe alginate impression materials? 1: impression plaster
1: Thermoplastic 2. non-aqueous elastomers
2. Elastomeric 3. zinc oxide eugenol
3. Thermoset 4, alginate hydrocolloid
4. Irreversible elastic 5. impression wax
5. Reversible plastic Ans: 5
Ans: 4
266. During the calcining of gypsum?
261: Human teeth possess which of the 1: it is subjected to temperatures of 110 to
following hue portions of the color spectrum? 120°F
1: Yellow and yellow-red 2. part of water of crystallization is deriven off
2. Red and yellow-red 3. silica is added
3. Green and yellow-green 4. it is boiled in distilled water
4. Yellow-red and yellow-green 5 all of the above
5. Red. green, and blue Ans: 2
Ans: 1
267. Amongst the non-aqueous elastomeric
impression materials curing time is longest for
the?
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1: polyethers 2. kaolin
2. condensation silicones 3. quartz
3. polysulfides 4. lime
4. addition silicones Ans: 2
Ans: 2
273. Which of the following is an advantage of
268. Gypsum bonded investments contain? the fluid resin technique of processing
1: alpha- hemihydrate dentures?
2. beta- hemihydrate 1: Improved bonding of resin to teeth
3. dihydrate 2. Teeth do not shift
4. none of the above 3. Better tissue fit
Ans: 1 4. Avoidance of air inclusion porosities
Ans: 3
269. The boiling point of pure methyl meth-
acrylate is? 274. The most commonly used initiator in
1: 104°C denture base resins is?
2: 96.2°C 1: benzene
3: 100.8°C 2. hydroquinone
4: 111.3°C 3. benzoyl peroxide
Ans: 3 4. methyl peroxide
5. Heat
270. Compared to the unfilled restorative resins Ans: 3
cured by the benzoyl peroxide-tertiary amine
system, 275. The best method of regulating the setting
those cured by the sulfinic acid system? time of gypsum products is by varying the?
1: are more sensitive to inhibition by phinolic 1: concentration of modifying chemicals
compounds 2. temperature of mixing water
2. deteriorate more rapidly on storage 3. W/P ratio
3. are less affected by water or moisture during 4. time of spatulation
polymerization 5. speed of spatulation
4. all of the above Ans: 1
5. none of the above
Ans:2 276. The mercury used for dental amalgam
alloys should?
271: What is the primary objective of 1: not contain more than 1.5% arsenic
trituration? 2. contain less than 0.2 % non-volatile residue
1: Pushing the mercury in to the alloy particles 3. be triple distilled
mechanically 4. contain less than 1.5% volatile residue
2. Breaking the alloy particles into smaller Ans: 2
fragments
3. Removal of impurities from the surface of the 277. Which of the following may be used as a
mercury particles filler in composite resins ?
4. Removal of the oxide film of the alloy 1: Crystalline quartz
particles 2: Lanthanum glass
Ans: 4 3. Beta-eucryptite
4. Lithium glass ceramics
272. The binder in porcelain is? 5. All of the above
1: soda form of feldspar Ans: 5
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Ans: 4
278. All of the following are grain refiners of
noble metal casting alloys, except? 283. Liquids which become more rigid as the
1: rhenium rate of deformation increases are termed
2. ruthenium 1: thixotropic
3. iridium 2. newtonian
4. all of the above 3. pseudoplastic
5. none of the above 4. plastic
Ans: 5 5. Dilatants
Ans: 5
279. The commonly used composite restorative
materials have a matrix based upon? 284. The setting time of zinc oxide - eugenol
1: vinyl resins paste will be decreased by?
2. epoxy resins 1: cooling the glass slab employed for mixing
3. alkyl resins 2. using a very short mixing time
4. ester resins 3. adding a small amount of petrolatum to the
Ans: 2 mix
4. increasing the ratio of base paste to the
280. Which substance is usually adsorbed onto catalyst paste
the surface of gold foil by manufacturers, to act 5. none of the above
as a Ans: 5
protective film?
1:Chromium oxide 285. Cohesion of direct filling gold at room
2. Ammonia temperature Is an example of the principle of?
3. Oxygen 1: homogenization
4. Sulfur dioxide 2. wedging
Ans: 2 3. atomic attraction
4. brazing
281: Bonding agents improve the bond strength 5. annealing
of composite resins to the tooth structure by? Ans: 3
1: chemical adhesion to enamel
2. forming complex chelates with the inorganic
portion of tooth structure 286. The primary role of modifiers in dental
3. decreasing the surface tension of composite plasters is to?
resin 1: increase strength
4. improved wetting and penetration into the 2. reduce porosity
enamel irregularities 3. regulate the setting time
5. all of the above 4. control the hygroscopic expansion
Ans: 4 5. increase hardness
Ans: 3
282. The principal factor in minimizing the firing
shrinkage of porcelain is the? 287. After plaster is mixed, which of the
1: amount of hydrated aluminium silicate following is the first to occur?
present 1: Gillmore needle - final setting time
2. fusion temperature 2. Loss of gloss
3. uniformity of particle size 3. Vicat needle - setting time
4. thoroughness of condensation 4. Gillmore needle - initial setting time
5. ratio of silica and alumina Ans: 2
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2: 3.6
288. The thickness of the gel between the tray 3: 9.4
and the tissues for hydrocolloid impressions 4: 1.7
shouldalways he at least? Ans: 4
1: 3 mm
2: 1.5 mm 295. A measure of the ductility of a material is
3: 6 mm its?
4: 1 mm 1: hardness number
Ans: 1 2. percent elongation
3. tensile strength
289. Commercially pure titanium is the dental 4. flexibility
implant material of choice as it? 5. yield strength
1: has very low density Ans: 2
2. oxidizes upon contact with air or normal
tissue fluids 296. Water at 20°C is more suitable for cooling
3. has a modulus of elasticity 5 to 10 times the agar hydrocolloid impression than is ice
higher than that of bone water
4. induces bone formation because the sol is a good thermal conductor
Ans: 2 and rapid cooling may cause a concentration of
stresses
290: Compared to heat-curing resins, chemically where gelation takes place last.
activated resins have increased? 1: Both the statement and reason are true
1: strength 2. The statement is true but the reason is false
2. color stability 3. The statement is false but the reason is true
3. residual monomer content 4. Both the statement and reason are false
4. working time Ans:2
5. none of the above
Ans: 3 294. The dentist can decrease the setting
expansion of plaster by?
291. Which of the following acids is commonly 1: increasing the W/P ratio
used for etching enamel surfaces? 2. selecting a plaster with a finer particle size
1: Citric acid 3. reducing the accelerator concentration
2. Hydrochloric acid 4, increasing the mixing time
3. Phosphoric acid 5. adding powered gypsum to the mix
4. Picric acid Ans:1
Ans: 3 297. At a temperature of 650°C, when the
gypsum investment mold is adequately heated,
292. The liquid for glass ionomer cements is the colour of
similar to that of? the sprue when viewed in a shadow, is?
1: zinc phosphate cements 1: dull red
2. resin cements 2. cherry red
3. polycarboxylate cements 3. bright orange
4. silicate cements 4. light orange
Ans: 3 Ans: 2

293. The pH of poly-carboxylate cement liquid 298. Oil of clove contains?

containing poly-acrylic acid, is approximately 1: 100 % eugenol
1: 6.2 2. 70-85 % eugenol
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3. 50-60 % eugenol 304. When pure metals solidify, super cooling is

4. 15-25% eugenol not necessary for?
Ans: 2 1: homogenous nucleation
2: heterogenous nucleation
299. Silver in the dental amalgam alloys? 3. polygamous nucleation
1: decreases ductility 4. monogamous nucleation
2. decreases the setting time Ans: 2
3. minimizes the formation of oxides
4. increases plasticity 305. A plasticizer used in methyl methacrylate
Ans: 2 resins Is?
1: ethyl silicate
300: The Vickers hardness number of a 2. butyl acrylate
tempered steel bur is 800, whereas that of a 3. alkyl sulfonate
tungsten carbide 4. ethylene methaciylate
bur is? Ans: 3
1: less than 1000
2: 5000-6000 306. The function of monomer added to the
3: 900-1100 heat-curing resin polymer, is primarily to?
4: 1500-1600 1: produce a plastic mass that can be packed
Ans: 4 into the mold
2. start the polymerization reaction
301: Acid etching procedures with a resin 3. reduce the porosity and increase the strength
system do not help in? of the appliance
1: preventing thermal exchange 4. provide adhesion of the resin base to the
2. retaining the resin teeth
3. providing a clean tooth surface for the resin Ans: 1
4: reducing microleakage
Ans: 1 307. Compared to the interior of the grain, the
grain boundaries of metals?
302. The greatest potential for marginal leakage 1: have greater impurities
related to temperature change occurs in? 2. have a more crystalline structure
1: zinc phosphate cement 3. are not as easily attacked by Chemicals
2. amalgam alloy 4. have lower energy
3. direct Idling gold Ans: 1
4. composite resin
5, unfilled resin 308. The resistance of inlay wax to cracking and
Ans: 5 flaking is due to the addition of?
1: dammar resin
303. Porosities that may occur during the 2. carnauba wax
processing of a denture will result in? 3. ceresin
1: difficulty in proper cleaning of the denture 4. ivory wax
2. increased warpage of the denture Ans: 1
3. the denture being unsightly
4. weakening of the denture 309. A silicon carbide abrasive designated 180
5. all of the above indicates, that the?
Ans: 5 1: particle size of silicon carbide is 180 microns
2. abrasive can pass through a sieve With 180
meshes to the inch
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3. abrasive is to be used on a work with a VHN 4. propagation

of not less than 180 5. cross-linking
4. VHN of the abrasive is 180 Ans: 1
Ans: 2
315. Which component of the denture base
310. Storage of alginates at higher resin is usually implicated in the dermatitis
temperatures results in the alginate constituent reactions occurring in
being? dentists or laboratory technicians handling
1: coagulated them?
2. precipitated 1: Pigment
3. depolymerized 2. Hydroquinone
4. flocculated 3. Polymer
5. any of the above 4. Benzoyl peroxide
Ans: 3 5. Monomer
Ans: 5
311. Which of the following will not result in
processing stresses in a heat cured compression 316. An amalgam is an alloy?
molded denture 1: of two or more metals
base? 2. one of whose constituents is silver
1: Water sorption 3. of silver and tin
2. Friction between mold walls 4. one of whose constituents is mercury
3. Differences in thickness of various areas of Ans: 4
the denture
4. Localised polymerization shrinkage 317. The lower limit of the melting range of
5. None of the Above noble metal casting alloys is important for
Ans: 5 estimating the?
312. Pit and fissure sealants are based on BIS- 1: casting temperature
GMA resins or? 2. soldering temperature
1: polycarbonate resins 3. firing temperature
2. polyurethane resins 4. welding temperature
3. polyvinyl resins 5. none of the above
4: polysulphide resins Ans: 2
Ans: 2
318. Agar hydrocolloid gel should be liquefied
313. Dental burs usually have? by heating at?
1: negative rake angles 1: 40-45°C
2: 45° rake angles 2: 100°C
3: 90° rake angles 3: 80-85°C
4: positive rake angles 4: 65°C
Ans: 1 Ans: 2

314. The exchange of a hydrogen atom from 319. An effective retarder for the lead dioxide
one growing chain to another, in an addition cured polysulfide impression materials is?
polymerization, will 1: glycoxylic or osmic acid
result in chain? 2. edetic or valproic acid
1: termination 3. picric or carminic acid
2. induction 4. oleic or stearic acid
3. transfer Ans: 4
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325. The attraction between atoms or

320. The crystallization of pure molten metals molecules because of van der Waals forces is
begins when the temperature is? due to?
1: at the freezing point 1: magnetic oscillations
2: slightly below the fusion temperature 2. a static electron field
3. slightly above the solidification temperature 3. a fluctuating dipole
4. at the melting point 4. the sharing of a valence electron
Ans:2 5. electron rotation
Ans: 3
321. The greatest stress to which a structure
can be subjected and return to its original 326. Which of the following is formed when
dimensions when the gypsum is calcined at temperatures 500°C?
forces are released is the? 1: Orthorhombic anhydrite
1: modulus of elasticity 2. Calcium sulfate dihydrate
2. elastic limit 3. Calcium sulfate hemihydrate
3. stress 4: Hexagonal anhydrite
4. tensile strength Ans: 1
5. Malleability
Ans: 2 327. The filler used in impression compound is?
1: bees wax
322. When curing a denture base, if insufficient 2. zinc phosphate
pressure is used while packing, porosity will be 3. French chalk
seen? 4. guttapercha
1: at the denture periphery 5. zinc phosphate powder
2. in the frenum areas Ans: 3
3. in the thickest portion of the denture
4. uniformly distributed throughout the denture 328. Which of the following impressions can be
base most safely transported to the dental
5. at the junction of the teeth and acrylic base laboratory?
Ans: 4 1: Polysullides
2. Alginates
323. The weakest phase of set amalgam is? 3. Addition silicones
1: gamma 4. Agar hydroColloids
2. gamma-1 5. Condensation silicones
3. gamma-2 Ans: 3
4. beta-2
Ans: 3 329. The flux used when casting gold alloys?
1: helps to prevent oxidation of the alloy
324. Methyl methacrylate? 2. contains borax and boric acid
1: does not react with fully polymerized acrylic 3. increases fluidity of the metal
resin 4. all of the above
2: is a poor organic solvent 5. none of the above
3: has a boiling point below that of water Ans: 4
4: is an opaque ,dirty, white colored liquid
5: none of the above 330. The severest pulp response is produced
Ans: 5 when which of the following cements Is applied
to freshly cut dentin?
1: Zinc phosphate cement
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2. Zinc oxide - eugenol cement Ans: 1

3. Resin cement
4. Glass ionomer cement 336. Which of the following is true for cast gold
Ans: 3 alloys?
1: Decreasing the gold content will increase the
331. Porcelains are made opaque by the mechanical properties, except elongation,
addition of oxides of? which decreases
1: iron and aluminium 2. Decreasing the gold content will decrease the
2. boron and magnesium mechanical properties, except elongation,
3. nickel and iridium which increases
4. titanium and tin 3. Increasing the gold content will increase the
Ans: 4 mechanical properties, except elongation,
which decreases
332. A 'cermet' is a combination of? 4. Increasing the gold content will decrease the
1: feldspar and quartz mechanical properties, including elongation
2. silver amalgam powder and glass ionorner 5. There is no correlation between the gold
powder content of gold alloys and their mechanical
3. conventional and aluminous ceramic properties
powders Ans: 1
4. the powders of polycarboxylate and
composite resin cements 337. A stone die can be made more abrasion
Ans: 2 resistant by?
1: treating the surface of set gypsum with a
333. Regarding gold alloys, the properties of the resin
solder joint are essentially the same as the parts 2. using aqueous colloidal silica when mixing
joined, except? the stone
1: elongation 3. mixing the stone with a resin solution
2. yield strength 4. all of the above
3. ultimate tensile strength Ans: 4
4. resistance to corrosion
5. none of the above 338. A gold casting is recovered from the
Ans: 4 gypsum mold by?
1: sand blasting
334. Loss of corrosion resistance of austenitic 2. using high speed burs to cut through the
stainless steel by removal of chromium from investment
the gamma solid 3. quenching the ring with the mold in water
solution, is termed? 4. tapping the mold with a mallet and breaking
1: characterization it
2. sensitization Ans: 3
3. dechromization
4. Destabilization 339. The angle between the back of the tooth of
Ans: 2 the dental bur and the work, is termed?
1: radial angle
335. Relative to enamel, cementum abrades? 2. clearance angle
1: 35 times more rapidly 3. tooth angle
2: 10 times less rapidly 4. flank angle
3. 50 times more rapidly Ans: 2
4. Equally
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340. The characteristic translucency of the 345. Increased bond strength between resin
incisal portion of natural teeth, is achieved in teeth and resin denture bases, may be obtained
porcelain restorations by by?
the addition of? 1: using teeth having lesser cross-linking in the
1: body porcelain ridge lap area
2. enamel porcelain 2. grinding and roughening the ridge lap area of
3. aluminous porcelain teeth
4. opaque porcelain 3. applying monomer to the necks of teeth for a
Ans: 2 few minutes before packing resin
4. all of the above
341. Which of the following factors does not Ans: 4
affect the design of dental restorations?
1: Location of carious lesions 346. Polystyrene resins are injected into the
2. Results of two dimensional photoelasticity mold?
3. Number of surfaces involved 1: after softening under heat
4. Amount of forces on the restoration 2. following liquefaction with organic solvents
Ans: 2 3. in the doughy stage
4. when the powder-liquid mix is fluid
342. All of the following are true for Ans: 1
condensation resins, except?
1: reaction is slow 347. A solid solution of two metals is more likely
2. small molecules are eliminated during to be formed if the?
polymerization 1: metals have different valences and sizes
3. functional units may be joined by ester or 2. lattice structure of the two metals is different
sulfide linkages 3. two metals have a high degree of chemical
4. never become truly giant sized affinity
5. none of the above 4. metallic atoms differ less than 15% in size
Ans: 5 5. all of the above
Ans: 4
343. A material which cannot act as a plaster
separating agent is? 348. The most powerful grain refiner in noble
1: cotton fibers metal dental casting alloys is?
2. soap solution 1: palladium
3. potassium alginate solution 2. nickel
4. tin foil 3. iridium
5. liquid paraffin 4. gallium
Ans: 1 5. Indium
Ans: 3
344. Which of the following Is false? An Alginate
impression 349. The thermal shrinkage of phosphate
1: may exhibit a fluid exudate on the surface as bonded investments, occurring in the range of
a result of imbibition 200-400°C, is
2. will shrink as a result of syneresis accompanied by the evolution of?
3. should be at least 3mm thick 1: ammonia
4. will take up water and expand if kept wet 2. sulfur dioxide
5. none of the above 3. hydrogen
Ans: 1 4. Carbon
Ans: 1
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2. sodium peroxide
350. Which of the following elements is present 3. soda ash
in the highest percentage in amalgam alloy? 4. sodium sulfite
1: Silver 5. sodium perborate
2. Tin Ans: 5
3. Lead
4. Copper 356. The average particle size of modern dental
5. Zinc amalgam alloys is?
Ans: 1 1: 0.05 - 0.9 micrometer
2: 1- 5 micrometer
351. Lattice imperfections of metal 3: 100 - 140 micrometer
structures, in which a lattice position is left 4. 25-35 micrometer
vacant, are termed ? Ans: 4
1: interstitial point detects
2. vacancies 357. Concentrations higher than 50% of
3. edge dislocations phosphoric acid are not used for acid etching, as
4. line defects this would?
5. nonequilibrium defects 1: form a protective layer on enamel which
Ans: 2 protects the tooth from further dissolution
2. lead to massive decalcification of enamel
352. Gold alloys used for the fabrication of rods
saddle bars and clasps, are? 3. damage the pulp
1: Type I 4. make the etching process too fast to comfort
2. Type II Ans: 1
3. Type III
4. Type IV 358. The primary oxygen scavenger In noble
Ans: 4 metal casting alloys is?
1: iron
353: On heating to 600°C, which of the 2: zinc
following forms of silica would exhibit 3: copper
maximum expansion? 4: silver
1: Fused quartz 5. rhenium
2. Tridymilo Ans: 2
3. Cristobalite
4. Quartz 359. Sulfates added to agar hydrocolloids, serve
Ans: 3 as?
1: plasticizers
354. The plasticizer commonly used in non- 2. shrinkage controllers
aqueous elastomeric impresion materials is? 3. plaster hardeners
1: dibutyl phthalate 4. stress reducers
2. colloidal silica 5. Strengtheners
3. alkyl silicate Ans: 3
4. silane oligomer
Ans: 1 360. The color stability of self-curing resins is
inferior to that of heat-curing resins because of
355. Denture cleansers which clean by the?
liberating oxygen, contain? 1: less time required for curing
1: sodium chloride 2: breakdown of benzoyl peroxide
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3. evaporation of monomer
4. oxidation of tertiary amine 366. The BIS-GMA resin system is based upon?
5. all of the above 1: biisosulfate and glycol methylacrylate
Ans: 4 2. boron isomeric sulfur and glycic methacrylate
3. bisphenol A and glycidyl methacrylate
361. An excellent polishing agent for noble 4. biisostearate and gamma methylacrylate
metal alloys is? Ans: 3
1: corundum
2. aluminium oxide 367. All of the following are disadvantages of
3. rouge the fluid resin technique of processing
4. Silica dentures, except
Ans: 3 1: intraocclusion in the denture
2. incomplete flow of the material over the
362. A greater amount of cross-linking agent is necks of teeth
used in resin teeth, in order to? 3. poor bonding of teeth to resin
1: reduce their tendency to crazing 4. complicated deflasking procedures
2. facilitate their bonding to the denture base 5. none of the above
3. increase their flexibility Ans: 4
4: all of the above
5: none of the above 368. Metal spatulas are not used for mixing two
Ans: 1 paste system composite resins, as?
1: the mix may discolor
363. All of the following are characteristics of 2. the metal may corrode because of the acids
eutectic alloys, except? in the resin
1: The temperature at which eutectic occurs is 3. heat from the metal may be transferred to
lower than the fusion temperature of either the mix
constituents 4. none of the above, metal spatulas can be
2: they are generally brittle used
3: alloy solidifies at a constant temperature Ans: 1
4: components exhibit complete solid solution
but limited liquid solubility 369. Direct filling gold foil is heated in a flame,
5: none of the above prior to filling in the cavity, to?
Ans: 4 1: sterilize the gold
2. strain harden the noble metal
364. Typo IV gold casting alloys are used 3. remove surface impurities
fabricating? 4. promote grain growth
1: short span bridges 5. all of the above
2. removable partial denture Ans: 3
3. inlays
4. 3/4 crowns 370. A homogenized amalgam filling material as
Ans: 2 compared to an un-homogenized amalgam
filling material?
365. Gypsum in investment acts as? 1: has greater flow
1: filler 2. is more technique sensitive
2. binder 3: has no advantage over an un-homogenized
3. refractory one
4. Reactor 4. requires less mercury for trituration
Ans: 2 Ans: 4
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2. separation of the stone cast from the

371. Alginate impression materials? impression is very easy
1: are muco-compressive in comparison to zinc 3. it has high degree of strength
oxide-eugenol 4. clean up is very easy
2. are more dimensionally accurate than 5. there is no significant dimensional change
reversible hydrocolloids subsequent to hardening
3. are hydrophilic Ans: 5
4. should not be removed from the mouth till at
least 15 minutes after gelation 377. A major disadvantage of inlay casting wax
Ans: 3 is its?
1: low thermal conductivity
372. Recommended W/P ratio is lowest for? 2. flow
1: Type I plaster 3. high thermal expansion
2. Type II plaster 4. Hardness
3. Type III stone Ans: 3
4. Type IV stone
5. Type V stone 378. Which of the following materials is mixed
Ans: 5 with a vigorous figure-eight motion?
1: Calcium hydroxide cement
373. Acrylic resin restorations are compatible 2. Alginate hydrocalloid
with all of the following, except? 3. Dental plaster
1: Alcohol 4. Zinc phosphate cement
2. zinc phosphate cement 5. Phosphate bonded investment
3. copal varnish Ans: 2
4. eugenol
5. calcium hydroxide 379. Synthetic resins are used as restorative
Ans: 4 materials, principally because of their superior?
1: dimensional stability
374. In dental porcelain, metallic oxides 2. bonding characteristics
provide? 3. esthetics
1: color and increase strength 4: strength
2. color but decrease strength 5. fracture resistance
3. a refractory skeleton and give color Ans: 3
4. refractory skeleton and increase strength 380. Fracture of a metal having a granular
Ans: 1 appearance with little reduction in area at the
site of fracture, is termed
375. The characteristic that refers to the 1: tensile fracture
strength or degree of saturation for a particular 2. Inter-granular fracture
hue, is termed? 3. ductile fracture
1: value 4. brittle fracture
2. chroma Ans: 4
3. shade
4. Color 381. Oxides of all of the following elements in
Ans: 2 noble metal alloys help in bonding to porcelain,
except?
376. The most desirable property of zinc oxide- 1: nickel
eugenol paste is that? 2. iron
1: it is pleasing for the patient 3. tin
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4. iridium Ans: 4
Ans: 1
387. The wax with the lowest melting point is
382. The binder in phosphate investments is? 1: carnauba wax
1: cristobalite 2. bees wax
2. magnesium oxide and mono-ammonium 3. paraffin wax
phosphate 4. synthetic wax
3. manganese dioxide and phosphoric acid Ans: 3
4. alpha or beta hemihydrate
Ans: 2 388. The dimensional change of an amalgam
restoration is influenced by all of the following,
383. An agar hydrocolloid impression should be except?
stored? 1: particle size
1: In a 2% potassium sulfate solution 2. amount of copper
2. at room temperature and normal 3. trituration and condensation
atmospheric pressure 4. amount of mercury present
3. in 100% relative humidity 5. moisture contamination
4. in any antiseptic solution Ans: 2
5. in a bowl of clean water
Ans: 3 389. When flasking and packing acrylic resin
dentures a separating medium is used. It
384. Warpage of the maxillary denture, as the performs all of the following
stresses are relieved, is most likely to result in functions. except to?
an inaccurate fit in 1: prevent the monomer from soaking into the
the region of the? investing plaster
1: buccal flange 2. reduce the thickness of the resin flash
2. alveolar ridge 3. prevent the water of the investing plaster
3. palate from affecting the polymerization
4. labial flange 4. prevent the plaster of one half of the flask
Ans: 3 from adhering to the plaster of the other half
5. none of the above
385: The composition of the bonding agent, Ans: 2
employed for composite resins is?
1: basically that of the filler of its companion 390. The initiator used in visible light cured
composite resin resins is?
2. styrene rubber and a coupling agent 1: benzoyl peroxide
3. basically that of the matrix of its companion 2. benzoin methyl ether
composite resin 3. aromatic ketones
4. Poly-vinyl siloxane and a thinner 4. biacetyl
Ans: 3 5. tertiary amines
Ans: 1
386. The desired polymer structure of denture
base resins is? 391. When inlay wax is softened in a water
1: face centered cubic bath, which of the following is the least harmful
2. fluid of the consequences?
3. body centered cubic 1. Distortion of the pattern upon thermal
4. Non-crystalline changes
5. Crystalline 2. Smearing of the wax surface upon polishing
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3. Leaching out of plasticizers Ans: 2

4. Spattering of the wax upon flaming
Ans: 3 397. Rare earth magnets used in over-denture
retention, are made from?
392. The working time of a heat-curing resin 1: palladium-iridium-iron alloys
mix, is the time? 2. silicon-germanium alloys
1: from the start of mixing till the 3. cobalt-samarium alloys
polymerization begins 4. ruthenium-molybdenum-zirconium alloys
2. from stringy state till the material reaches Ans: 3
tacky stage
3. from mixing till the mass sets 398. Elastomeric impressions can be safely
4. till the material remains in doughy stage disinfected by?
Ans: 4 1: immersion in 2% glutaraldehyde for 10
minutes
393. All of the following processes can be 2. overnight ethylene oxide gas sterilization
performed at room temperature, except? 3. autoclaving
1: work hardening 4. spraying phenol
2. forging Ans: 1
3. cold working
4. strain hardening 399. The polymerization reaction of methyl
Ans: 2 methacrylate is inhibited in the presence of ?
1: impurities
394. The rate of abrasion can be increased by 2. oxygen
increasing the? 3. hydroquinone
1: size of the abrasive particles 4. all of the above
2. speed of the bur or wheel 5. none of the above
3. pressure of the work Ans: 4
4. all of the above
5. none of the above 400. Increasing the polymer/monomer ratio will
Ans: 4 reduce?
1: formaldehyde release from self-curing resins
395. When a gelatin sol changes to gel form, the 2. reaction time of heat-curing resins
dispersed phase agglomerates to form chains or 3. shrinkage of heat-curing resins
fibrils, termed? 4. all of the above
1: stellites 5. none of the above
2. micelles Ans: 4
3. syngenites
4. hysteresis 401. For visible light cured resins, the light has a
5. Brushites wavelength of?
Ans: 2 1: 700 nm
2. 400 nm
396. Crazing of dentures occurs as a result of? 3. 200 nm
1: leaching out of the plasticizer 4. 850 nm
2. relaxation of surface stresses Ans: 2
3. high polymer-monomer ratio
4. dipping the denture in water 402. Water contamination of amalgam
5. stresses incorporated above the glass restoration during trituration or condensation,
transition temperature of resin resulting In pain, occurs
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mostly with? 4. patients and their attendants in the waiting

1: zinc containing alloys area
2. high copper alloys Ans: 2
3. Non-copper alloys
4. zinc free alloys 407. Denture base resins used in injection
Ans: 1 molding technique are?
1: polystyrenes
403. Usually gold casting alloys are solutions 2. polycarbonates
heat treated, by heating at? 3. vinyl resins
1: 700 °C for 2 min and then quenching in water 4. acrylic resins
2. 400°C for 30 min and then slow cooling to Ans: 1
room temperature
3. 700°C for 10 min and then quenching 408. Which of the following is an advantage
4. 400°C for 15 min and then quenching it in which the silicone impression materials have
water over mercaptans?
Ans: 3 1: Longer working lime
2. Better odor
404. The strength of alginate gel is increase? 3. Easier to pour in stone
1: if too much water is used in mixing 4. Decreased elasticity
2. because of insufficient spatulation Ans: 2
3. due to prolonged spatulation
4. if too little water is used in mixing 409. Porcelain denture teeth
5. none of the above 1: should be used where inter-alveolar
Ans: 5 clearance is small
2. are very easy to grind and polish
405. Which of the following is true regarding 3. have a higher coefficient of thermal
the measurement of working time and setting expansion than resin teeth
time of etastomeric 4. have a lower abrasion resistance than dentin
impression materials? 5. are more resistant to abrasion than gold
1: Setting time is measured at room Ans: 5
temperature and working time at mouth
temperature 410. The temperature at which a solid changes
2. Working time is measured at room to liquid is known as its?
temperature and setting time at mouth 1: vapour temperature
temperature 2. heat temperature
3. Both working and setting times are measured 3. fusion temperature
at mouth temperature 4. temperature of specificity
4. Both working and setting times are rr sured at Ans: 3
room temperature
Ans: 2 411. All of the following criteria may be used in
the classification of dental porcelains, except?
406. The greatest risk of toxic reactions from 1: fusion temperature
the mercury used in amalgam restorations, is 2. firing atmosphere
for? 3. color
1: patients getting their teeth restored 4. use
2. dentists and their auxiliaries 5. none of the above
3. laboratory technicians Ans: 3
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412. All of the following organizations are 4. Both would be of similar strength
responsible for the establishment of Ans: 1
specifications for dental materials,
except? 417. Nickel in high percentages, in noble metal
1: IDMA dental casting alloys?
2. FDI 1: increases ductility
3. ANSI 2. decreases tarnish resistance
4. ISO 3. decreases strength
5. none of the above 4. all of the above
Ans: 1 Ans: 2

418: The expansion of phosphate bonded

investments can be increased by ?
413. When the bottle containing liquid for zinc 1: using distilled water for mixing
phosphate cement is left open for a long time, 2. increasing the mixing time
water absorption by 3. using colloidal silica for mixing
the liquid is evidenced by? 4. using phosphoric acid for mixing
1: crystal formation on the walls of the bottle Ans: 3
2. increased viscosity of the liquid
3. general cloudiness of the liquid 419. An alloy contains 18 parts gold and 6 parts
4. all of the above other metals. The alloy is?
5. none of the above 1: 200 fine
Ans: 5 2. 180 fine
414. When mixing addition silicone impression 3. 1000 fine
materials, how should the base paste and 4. 600 fine
catalyst paste be 5. 750 fine
proportioned? Ans: 5
1: Equal lengths of the two pastes are taken
2. Equal volume of the two pastes is mixed 420. What is the temperature to which gypsum
3. Equal weights of the two pastes are taken investment mold Is heated in the low heat
4. The ratio of the two pastes is not critical if technique of cassting?
spatulation is proper 1: 650*C
Ans: 1 2. 350°C
415. The percentage of hydroquinone added to 3. 500°C
pure methyl methacrylate in dental is less than 4. 900°C
1: 0.01% Ans: 3
2: 0.006%
3: 0.8% 421. Which of the following Impression material
4: 2.3% is of the elastic type?
1: impression plaster
416. If of a similar composition, which would be 2. Agar hydrocolloid
stronger, cast gold or wrought gold wire? 3. Impression wax
1: Wrought wire would be stronger because of 4. Zinc oxide – eugenol
the cold working effect Ans: 2
2. Cast gold would be stronger because of heat
treatment 422. Which type of stainless steel is most
3. Cast gold would be weaker as it cannot be susceptible to corrosion?
cold worked 1: Ferrite
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2. Martensite Ans: 4
3: 18-8 steel
4. Austenite 428. Stiffness and strength of the agar gel will
Ans: 2 be less
1: when the brush heap density is more
423. Each crystal of a polycrystalline metal is 2. if the temperature is decreased
termed? 3. if more fillers are added
1: dendrite 4. if the concentration of the dispersed phase in
2. grain the sol is more
3. bush 5. none of the above
4. seed Ans: 5
Ans: 2
429. The Knoop hardness number of heat-
424. The best method of reducing the final curing poly (methyl methacrylate) resins,
mercury content of an amalgam restoration is? though slightly more
1: to reduce the original mercury/alloy ratio than self-curing resins, is in the range of?
2. by squeezing out excess mercury from the 1: 50-60
mixed amalgam using a squeeze cloth 2. 84-90
3. by burnishing the final restoration, thus 3. 10-12
bringing the excess mercury to the top 4. 19-21
4. by using a chamois leather to squeeze Out Ans: 4
excess mercury from the mix
Ans: 1 430: Metals have the property of malleability
and being made lustrous, because of their?
425. Which of the following factors favor 1: ease of giving up the valence electrons
crystallinity of resins? 2. good thermal conductivity
1: Random arrangement of side groups 3: high melting point
2. Long, branched polymers 4: high electrical conductivity
3. Addition of plasticizers Ans: 1
4: All of the above
5. None of the above 431. Where does the maximum polymerization
Ans: 5 shrinkage occur, when a Class V cavity is filled
with direct
426. The coupling agents employed in fining resins held in position with the aid of a
composite resins are basically? matrix strip?
1: glycol compounds 1: On the surface
2. vinyl derivatives 2. Along the pulpal wall
3. silane compounds 3. Along the cervical wall
4. butyl rubber derivatives 4. Along the occlusal wall
Ans: 3 5. Uniformly throughout
Ans: 2
427. Cross-linking of condensation silicones
occurs through a reaction with? 432. Porcelain denture teeth are used ?
1: potassium titanium fluoride 1: when high wear resistance is desired
2. benzoyl peroxide 2. to oppose gold or natural teeth
3. Methanol amine 3. when there is diminished inter-occlusal
4. tetraethyl orthosilicate distance
5. T-butyl hydroperoxide 4. It the ridges are resorbed
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5. all of the above 4. cavity should be slightly underlined, so that

Ans: 1 burnishing will ensure good marginal fit
Ans: 2
433. Strain hardening of a metal decreases its?
1: surface hardness 438. Stain removing commercial denture
2. strength cleansers, usually contain?
3. resistance to corrosion 1: soda ash
4. proportional limit 2. sodium perborate
Ans: 3 3. potassium perborate
4. hydrochloric acid
434. All of the following metals have a 5. sodium hypochlorite
whitening effect on gold alloys, except? Ans: 5
1: silver
2. platinum 439. The heat treatment of "soaking” the alloy
3. palladium at a high temperature to produce a solid
4. all of the above solution,
5, none of the above followed by quenching is known as?
Ans: 5 1: solution heat treatment
2. age hardening
435: Hygroscopic expansion of gypsum banded 3. liquid heat treatment
investments is? 4. strain hardening heat treatment
1: because of the confinement of the growing Ans: 1
crystals by surface tension of the excess water
2. a continuation at the ordinary setting 440. The propensity of some noble metal alloys
expansion to cause green stains at the margin of the
3. lesser when the amount of quartz is metalporcelain
increased interlace, is due to the presence of?
4. a chemical phenomenon 1: oxygen
5. all of the above 2. zinc
Ans: 2 3. silver
4. platinum
436. The purpose of expansion of the gypsum 5. Tin
investment mold is to compensate for the? Ans: 3
1: distortion of the wax pattern
2. casting shrinking of the alloy 441. The structure of alginates when set is most
3. shrinking of the die similar to that of?
4. expansion of the wax pattern 1: dental plaster
5. dimensional change of the impression 2. reversible hydrocolloids
Ans: 2 3. impression compound
4. polymethyl methacrylate
437. During the condensation of amalgam into a Ans: 2
cavity, the?
1: condensation should be started at the 442. A noble metal casting alloy containing
peripheries, slowly moving towards the center iridium will have?
2. cavity should be slightly overfilled 1: high yield strength
3. amalgam should be carried in one or two 2. fine grain size
large increments 3. high elongation
4. better tarnish resistance
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5. all of the above 2. Shore A hardness number

Ans: 5 3. Brinell hardness number
4. Rockwell hardness number
443. A filler which may be used in poly-sufide Ans: 2
impression materials is?
1: oleic acid 447. An impression, made in impression
2. titanium dioxide compound, should be poured immediately in
3. silicate plaster to
4. potassium sulfate eliminate discrepancies resulting from?
5. none of the above 1: polymerization shrinkage
Ans: 2 2. syneresis
3. hysteresis
444. The operator can overcome the low 4. dehydration
thermal conductivity of impression compound 5. stress relief
by? Ans: 5
1: giving adequate time to cool completely
before removing the Impression from the 449. The dry strength of set plaster will he
mouth increased when?
2. holding the tray firmly under pressure once 1: W/P ratio is increased
placed in the mouth 2. porosity is high
3. dipping the tray with compound in a bowl of 3. accelerators or retarders are added
water for 15 min at 50*C 4. the mixture is overmixed
4. pouring the permanent cast in stone 5. none of the above
5. not stressing the compound when it is placed Ans: 5
in the mouth
Ans: 1 450. All of the following are desirable
characteristics of an abrasive agent, except that,
445. Which component of zinc oxide-eugenol it should?
impression paste acts as plasticizer? 1: present a round smooth surface to the work
1: Kaolin or diatomaceous earth 2. be harder than the work
2. Canada or Peru balsam 3. possess high impact strength
3. Calcium chloride or zinc acetate 4. fracture rather than dull
4. Rosin or lanolin 5. none of the above
5. Vegetable or mineral oil Ans: 1
Ans: 5
451. The cross-linking agent used for polysulfide
446. Plaster on hardening will show a linear polymers is?
expansion of? 1: dimethyl siloxane
1: less than 0.01% 2. ethyl alcohol
2: 0.01% to 0.05% 3. lithopone
3: 0.15% to 0.30% 4. lead dioxide
4: 0.5% to 1.5% 5. benzoyl peroxide
5: 21% Ans: 4
Ans:3
452. The most commonly used separating
448. The hardness of rubbers and elastomers is media for curing dentures is?
expressed as? 1: soaps
1: Knoop hardness number 2. starches
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3. water soluble alginates 458. When restoring a tooth with composite

4. cellulose lacquers resins, the matrix strip used to contour the resin
5. tin foils should be
Ans: 3 held in place until
1: polymerization begins
453. In the direct technique of fabricating in-lay 2. the probe tip is no longer able to panetrate
wax patterns, the wax pattern is pre-pared? the material when pushed with light finger
1: by pouring molten wax into the impression pressure
2. prior to tooth preparation 3. polymerization is complete
3. on the tooth itself 4. the material hardens
4. on the master die Ans: 4
Ans: 3
459. The setting time of non-aqueous
454. Carnauba Wax is added to basic paraffin elastomeric impression materials is the same as
wax to? the?
1: ensure uniformity of hatches 1: working time
2. improve the smoothness in molding 2. curing time
3. render it resistant to clacking and flaking 3. mixing time
4. decrease flow at mouth temperature 4. polymerization time
Ans: 4 5. none of the above
Ans: 5
455. In a constitutional phase diagram, in the
area below the solidus, the metal is in? 460. Alginates are made dustless by the
1: a liquid state addition of?
2. a solid state 1: wintergreen
3. an amorphous state 2. anise
4. both a solid arid a liquid state 3. glycol
5. a non-crystalline state 4. silicate powder
Ans: 2 5. Borates
Ans: 3
456. A byproduct of the setting reaction of
condensation silicone elastomeric materials is? 461. With some addition silicone impression
1: methane materials, pitting of the stone cast may occur as
2. benzoyl peroxide a result of
3. hydrogen escaping?
4. ethyl alcohol 1: ethyl alcohol
5. Water 2. nitrogen gas
Ans: 4 3. helium gas
4. hydrogen gas
457. The average processing shrinkage of a 5. Water
heat-curing resin denture is ? Ans: 4
1: 0.005%
2: 0.05% 462. The restorative material having hardness
3: 0.5% nearest to that of enamel is?
4: 5.0% 1: micro-filled composite resin
Ans: 3 2. direct filling gold
3. silicate cement
4. Amalgam
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Ans: 4 468: When performing the Vickers hardness

test, the indenting tool is in the shape of?
463. The primary objective of condensation of 1: a 136degree diamond pyramid
an amalgam mix is to? 2. a blunt pointed cylinder
1: ensure uniform distribution of mercury 3. a rhomboidal pyramid
2. force amalgam into all parts of the cavity 4. a conical diamond
3. produce layering Ans: 1
4. bond the unattached sigma particles together
5. break up the matrix 469. Impression plasters are plaster of Paris to
Ans: 2 which modifiers have been added. Modifiers
are added
464. The gypsum product having the highest to?
setting expansion is? 1: decrease porosity and to increase strength
1: Type I plaster 2. regulate setting time and to control setting
2. Type II plaster expansion
3. Type III stone 3. increase flow and to decrease solubility
4. Type IV stone 4. prevent formation of exothermic heat and to
5. Type V stone control warpage
Ans: 5 Ans: 2

465. Self polymerizing acrylic resins differ 470. Canada balsam or Peru balsam are added
from heat-cured resins, in that, they? to zinc oxide-eugenol primarily to?
1: have higher color stability 1: mask the irritating action of eugenol
2. have lower residual monomer content 2. increase flow
3. are more porous 3. accelerate the setting reaction
4. have higher molecular weight 4. ensure a smoother mix
5. have a granter transverse strength 5. provide body to the mass
Ans: 3 Ans:2

466. Which of the following is true for both 471. Mercaptan rubbers are?
reversible and irreversible hydrocolloids? 1: polyether elastomers
1: They can be stored in a humidor with-out any 2. addition polymerizing silicones
dimensional change 3. polysulfide elastomers
2. They can be converted from gel to sol 4. condensation polymerizing silicones
3. An increase in temperature will retard Ans: 3
gelation
4. None of the above 472. The length of the sprue former depends
Ans:4 primarily on the?
1: length the of the casting ring
467. All of the following have been employed as 2. thickness of the wax pattern
pit and fissure sealants, except? 3. thickness of the sprue former
1: Methyl methacrylate resin 4. angle at which it is attached to the pattern
2. Cyanoacrylate resin Ans:1
3. Bis - GMA resin
4. Polyurethane resin 473. Zinc oxide-eugenol cement is not suitable
Ans: 1 for permanent cementation of restorations
because of
its?
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1: lack of thermal protection to the pulp Ans: 3

2. high solubility
3. lack of ability to seal the margins 479. The cement of choice for temporary
4. lack of strength restorations in areas of the mouth not
Ans: 4 subjected to high stress,
is?
474. The antiflux used for gold solders is? 1: zinc oxide eugenol
1: silicon 2. calcium hydroxide
2. titanium 3. glass ionomer
3. cryolite 4. composite resin
4. graphite Ans: 1
Ans: 4
480. The melting point of pure gold is?
475. In porcelain fused to metal restorations, 1: 1060°C
some of the most commonly used alloys have a 2. 720°C
base of? 3. 1500°C
1: platinum 4. 580°C
2. chromium Ans: 1
3. silver
4. gold 481. A wax pattern should be invested as soon
5. Palladium as possible after it is fabricated, in order to
Ans: 4 minimize
changes in shape because of?
476. The ability of direct filling gold to be 1: changes in room temperature
welded together at room temperature, is 2. relaxation of internal stresses
because of its 3. expansion of wax
malleability and? 4. decrease in the flow of wax
1: lack of oxide surface coating Ans: 2
2. high thermal conductivity
3. extreme softness 482. Which of the following is true regarding
4. high degree of purity porosity in an acrylic denture?
Ans: 1 1: Internal porosity occurs uniformly
throughout the denture
477. Compared to unfilled acrylic resins, 2. Porosity is common if there is homogeneity in
conventional composite resins have a greater? the dough or gel at the time of polymerization
1: hardness 3. Gaseous porosity appears as small bubbles
2. polymerization shrinkage evenly distributed throughout the denture
3. linear coefficient of thermal expansion 4. None of the above
4. water sorption Ans: 4
5. all of the above
Ans:1 483 Which of the following substances is used
as a refractory in investment powders?
478. The recommended mercury: alloy ratio for 1: Borax
most modern dental amalgam is? 2. Calcium sulfate hemihydrate
1. 1.5:1 3. Silica
2. 1:2 4. Calcium sulfate dihydrate
3. 1:1 5. Sodium diphosphate
4. 2:1 Ans: 3
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1: calculating weight loss

484. All of the following are properties of cobalt 2. using radioactive tracers
- chromium - nickel wires, except? 3. measuring dimensional change
1: they can be heat treated 4. all of the above
2. they have excellent tarnish and corrosion 5. none of the above
resistance Ans: 4
3. their hardness is comparable to stain-less
steel 489. An 18 gauge SS wire has a diameter of?
4. they cannot be soldered or welded 1: 1.562 mm
5. none of the above 2. 1.024 mm
Ans: 4 3. 0.638 mm
4. 2.164 mm
485. The abrasive effect of a dentifrice on the Ans: 2
tooth, primarily depends on which factor of
tooth 490. Which of the following defects in casting is
brushing? not because of the solidification shrinkage of
1: Diameter of the bristles the alloy?
2. Frequency and manner of brushing 1: Suck-back porosity
3. Wetness of the bristles 2. Microporosity
4. Whether bristles are made of nylon or 3. Localised shrinkage porosity
natural fibers 4. Subsurface porosity
5. All of the above Ans: 4
Ans: 2
491. When mixing heat-curing resins, if the
486. Despite its acidic nature polycarboxylate polymer/monomer ratio is higher, the?
cement fails to cause any damage to the pulp as 1: reaction time and shrinkage will be lesser
the? 2. reaction time and shrinkage will be more
1: large size of acid molecule prevents its 3. reaction time will be more but the shrink-age
diffusion through dentinal tubules will be lesser
2. cement attains neutrality rapidly 4. reaction time will be lesser but the shrinkage
3. acid gets diluted by the fluids of the dentinal will be more
tubules Ans: 1
4. acid forms complex chelates with the
hydroxyapatite molecules of enamel 492. A gold alloy, designated as 20 karat,
Ans: 1 contains?
1: 80% pure gold
487. The flux used for soldering stainless steel 2. 20 parts of pure gold with 4 parts of other
wires is similar to that used for gold solders metals
with the 3. 20 parts of pure gold with 80 parts of other
exception of the addition of? metals
1: stannous fluoride 4. only gold
2. sodium nitrate Ans: 2
3. potassium fluoride
4. calcium carbonate 493. The working time of a phosphate
Ans: 3 investment mix can be increased, by increasing
the?
488. Abrasiveness of tooth structure can he 1: liquid/powder ratio
measured by? 2. temperature of the mix
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3. mixing time and mixing efficiency 498: All of the following have the same
4. all of the above chemical formula, except?
Ans: 1 1: densite
2. hydrocal
494. Which of the following is important when 3. phosphate-bonded investment
using water soluble alginates as separating 4. impression plaster
media before 5. none of the above
packing resin into the mold? Ans: 3
1: Separating media should never be applied till
the flask reaches room temperature 499. Alu-wax contains?
2. The complete mold and tooth surface should 1: copper
be coated 2. silica
3. As thick a layer as possible should be applied 3. aluminium
4. Waxes or oils remaining on the mold surface 4. zinc oxide
will not permit the solution to make contact Ans: 3
with the
investment 500. Gypsum investments should not be heated
Ans: 4 above ?
1: 450°C
495. if a pure molten metal solidifies in a 2. 700°C
cylindrical mold, which is at a temperature 3. 1000°C
considerably below 4. 1250°C
the melting point of the metal, the grain Ans: 2
structure of the metal on solidification would
appear? 501. Amalgam dies may be made in?
1: columnar 1: irreversible hydrocolloid impressions
2: spherical 2. polyether impressions
3. basket 3. compound impressions
4. Radial 4. addition silicone impressions
Ans: 4 Ans: 3

496. Which of the following will form a 502: The process of manufacturing gypsum
peritectic alloy? products from gypsum is known as?
1: Silver and tin 1: milling
2. Silver and copper 2. sintering
3. Silver and gold 3. virtification
4. Silver and palladium 4. calcining
Ans:1 5. Fusing
Ans: 4
497: Base metal alloys have casting shrinkages
in the range of? 503. A dental resin exhibited brittle fracture
1: 2-2.3% when stressed, but the same material had been
2. 1-1.25% found to be
3. 3.4.2% ductile previously. The condition that was most
4. 1.2-1.6% likely altered during brittle failure was ?
Ans: 1 1: amount of load
2. testing temperature
3. strain rate
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4. load angulation 5. none of the above

Ans: 3 Ans: 3

504. With regard to elastomeric impression 509. How much volumetric shrinkage will occur
materials, the setting time ? during the polymerization of pure methyl
1: is less than the curing time methacrylate?
2. is equal to the curing time 1: 33%
3. is less than the working time 2. 60%
4. is more than the curing time 3. 21%
5. and curing time are not related 4. 30%
Ans: 1 5. 7%
Ans: 3
505. Malleability of a material can be expressed
as? 510. The conditioner 'or primer' for composite
1: percentage elongation resins may contain any of the following, except
2. proportional limit 1: aluminium oxalate and aluminium nitrate
3. shear strength 2, nitric acid and N-phenylglycine (NPG)
4. percentage compression 3. citric acid and resorcinol cyclo-oxalate (RCO)
5. Young's modulus 4. glutaraldehyde and hydroxyethyl meth-
Ans: 4 acrylate (HEMA)
5. 4-methyloxyethyltrimellitic anhydride (META)
506: A colloidal state in which a liquid is Ans: 3
distributed in another liquid is termed ?
1: suspension 511. The accuracy of the temperature of the
2. sol casting furnace may be verified by?
3. emulsion 1: observing the color of the mold in shadow
4. gel 2. using templets of chemicals that melt at a
5. Dispersion specific temperature
Ans: 3 3. reading the pyrometer
4. using a thermometer
507. In general. Ans: 2
1: malleability increases with decrease in
temperature 512. Glass lonomer cement liquids contain all of
2. ductility decreases with increase in the following, except
temperature 1: citric acid
3. ductility increases with increase in 2. itaconic acid
temperature 3. tartaric acid
4. malleability decreases with increase in 4. polyacrylic acid
temperature 5. none of the above
Ans: 2 Ans: 1
513. The purpose of heating direct filling gold
508. All of the following chemicals accelerate before its condensation is?
the setting reaction of gypsum products, 1: sterilization
except? 2. homogenization
1: 10% sodium chloride 3. volatilizing surface contaminants
2. potassium sulfate 4. softening
3. acetates 5. none of the above
4. potassium tartrate Ans: 3
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1: ultimate tensile strength

514. Wax elimination and heating of the 2. hardness
gypsum mold can be started, after the mold 3. toughness
1: has hardened for at least 12 hours 4. elastic limit
2. is completely dry 5, resilience
3. has hardened for at least one hour Ans: 3
4. is allowed to harden overnight
Ans: 3 520. A greater bulk of material will produce a
better impression if the material is
515. Which of the following cements does not 1: polysulfide
dissolve or erode in oral fluids? 2. wax
1: Resin cement 3. addition silicone
2. Polycarboxylate cement 4. polyether
3. ESA reinforced zinc oxide - eugenol cement 5. Alginate
4. Glass ionomer cement Ans: 5
Ans: 1
521: If a stone cast is immersed in running
516. The basic composition of dental porcelain water for 5 hours, its linear dimension is likely
Is? to be reduced
1: borax, feldspar, lime by
2. feldspar, quartz, kaolin 1: 25%
3. lime, quartz, feldspar 2. 15%
4. boric acid, kaolin, borax 3. 1.5%
Ans: 2 4. less than 0.01%
5. there will be no reduction of linear dimension
517. The ability of a cast gold inlay to be in running water
burnished is most accurately described, which Ans: 3
of the following
of its properties 522. In denture base resins, inhibitors are
1: Percentage elongation added to the monomer to
2. Flow 1: prolong the shelf life
3. Elastic unit 2. initiate the reaction
4. Stress 3. activate the monomer
Ans: 1 4. reduce the viscosity of the polymer
5. increase the time of the dough stage of the
518. After it is inserted, a silicate restoration resin
should not be finished for at least Ans: 1
1: 10 minutes
2: half an hour 523. A loss of vertical dimension is observed in
3: 6 hours complete dentures processed from
4: 24 hours 1: heat curing resins by compression molding
5: 72 hours 2. fluid resins in a hydrocolloid mold
Ans: 4 3. chemically activated resins by compression
molding
519. The area below the stress-strain Curve 4. pour type resins in a gypsum mold
showing the energy required to fracture the 5. injection moulded resins in a special flask
material is Ans: 2
known as the
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(KCD)

524. Conventional cavity varnishes containing

chloroform or ether are not used with resin 529. A gold solder designated 18 karat indicates
restorative that the solder
materials, as they 1: contains 75% pure gold
1: fail to prevent thermal sensitivity 2. is 600 fine
2. lead to open margins 3. can be heated to 180*C
3. inhibit the polymerization of resin 4. none of the above
4. irritate the pulp Ans: 4
5. all of the above
Ans: 3 530. A generally accepted curing cycle for heat-
curing resins is?
525. Most metals used in dentistry are of which 1: 75*C x 69min
lattice type? 2. 75*C x 30 min, followed by 30 mm of boiling
1: Rhombic 3. 65*C x 90 min, followed by 90 min of boiling
2. Orthorhombic 4. 500*C x 1.5 hours
3. Tetragonal Ans:3
4. Monoclinic
5. Cubic 531. The process of heating a cast alloy to
Ans: 5 eliminate composition differences (coring), is
termed
526. Which of the following is not likely to be an 1: annealing
ingredient in agar hydrocolloid impression 2. homogenization
material? 3. transformation
1: Wax 4. Recrystallization
2. Glycerine Ans: 2
3. Silica
4. Calcium chloride 532. Noble metal dental casting alloys are
5. Thymol classified according to their?
Ans: 4 1: melting temperature
2. malleability
527. The average total dimensional change 3. castabilily
occurring during the processing of a 4. dental function
compression molded, 5. age hardening capability
resin denture is approximately Ans: 4
1: 0.1-0.2mm
2. 0.001.0.002mm 533. When gypsum investments are heated to
3. 0.01-0.02mm 1000°C, the correct sequence of di-mensional
4. 1-2mm change
Ans: 1 would be
1: expansion, contraction, expansion
528. A primary undesirable characteristic of pit 2. expansion, shrinkage
and fissure sealants is ? 3. contraction, expansion
1: low coefficient of thermal conductivity 4. shrinkage, expansion, contraction
2. short working time Ans: 4
3. curing by ultra violet light
4. high tensile strength 534. Which of the following is a disadvantage of
5. low viscosity zinc oxide eugenol impression paste?
Ans: 5 1: Inaccuracies in producing surface detail
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(KCD)

2. Dimensional change upon hardening 4. Tray silicone

3. Stinging sensation Ans: 1
4, Poor flow
5. Inability to compress soft tissues 540. Methyl methacrylate may be activated by
Ans: 3 all of following, except
1: UV light
535. The agar hydrocolloid impression material 2. tertiary amines
must be conditioned before insertion in the 3. Stannous peroxide
patient's 4. sulfuric acid derivatives
mouth for all of the following reasons. except to Ans: 3
1: increase its viscosity
2. prevent the material from flowing out of the 541. The binder used in dentifrices is
tray 1: propylene glycol
3. prevent injury to mouth tissue 2. sorbitol
4. reduce dimensional change 3. Carboxy-methylcellulose
Ans: 4 4. Water
Ans: 3
536. The nucleation of a molten metal inhibited
by 'seeding', is referred to as? 542. The impression material producing the
1: heterogenous nucleation least accurate surface details is ?
2. monogamous nucleation 1: polyether
3. polygamous nucleation 2. reversible hydrocolloid
4. homogenous nucleation 3. irreversible hydrocolloid
Ans: 1 4. addition silicone
5. ZOE
537. The temperature at which sol changes to Ans: 3
gel is termed
1: solidification temperature 543. The molecules of one substance adhere to
2. gelation temperature molecules of another. The substance to which
3. crystallization temperature the
4. solution temperature molecules adhere to, is termed ?
5. glass transition temperature 1: adhesion
Ans: 2 2. adhesives
3. cohesion
538. Which of the following may be classified as 4. adherend
a composite material? Ans: 4
1: Gold foil
2. A filled resin 544. Abrasion of tooth structure is independent
3. Inlay wax of the stiffness or composition of the brush
4. Colloidal silica bristles. It
5. Copper phosphate cement depends almost entirely on the properties of
Ans: 2 the dentifrice used in conjunction with the
tooth brush.
539. Which of the following is an inelastic 1: The first statement is true and the second
impression material? false
1: Zinc oxide-eugenol 2. The first statement is false and the second
2. Agar agar true
3. Polysulfide 3. Both statements are true
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(KCD)

4. Both statements are false 550: When electroplating an impression with

Ans: 3 copper, the cathode is the?
1: cooper sulfate
545. Which of the following cements is not used 2: the impression being electroplated
as a thermal insulating base under restorations? 3. a copper plate or rod
1: Glass ionomer 4. distilled water
2. Calcium hydroxide Ans: 3
3. Polycarboxylate
4. Zinc oxide-eugenol 551: in size, the largest porosities in a casting,
5. Silicate are of which type?
Ans: 5 1: Microporosity
2. Pin hole
546. Which of the following forms of gypsum is 3: Suck back
of beta-hemihydrate form? 4: Gas inclusion
1: Type V investment Ans: 4
2. Densite
3. Gypsum bonded investment 552. The Brinell hardness number (BHN) of pure
4. Hydrocal gold Is
5. None of the above 1: 6
Ans: 5 2. 140
3. 25
547. The fusion temperature of impression 4. 1100
compound is approximately Ans: 3
1: 100°C
2. 65°C 553. All of the following alloy elements
3. 45°C participate in the solid solution hardening of
4. 30°C base metal alloys,except?
Ans: 3 1: iron
2. molybdenum
548. The addition silicones may show 3. aluminium
dimensional change as a result of 4. Copper
1: contraction because of cross-linking Ans: 3
2. loss of volatile accelerator component
3. evaporation of alcohol during setting 554. The hardest and most effective abrasive
4. extraction of the water soluble plasticizer for tooth enamel is
during setting 1: diamond
Ans: 1 2. tin oxide
3. emery
549. The strength of an amalgam restoration 4. Garnet
1: according to ADA specifications should be a Ans: 1
minimum of 20 MPa at the end of 1 hour
2. after 20 minutes will be 60% of its 1 week 555. Which of the following is a noble metal?
strength 1: Cobalt
3. reaches its peak after 3 hours 2. Copper
4. after 8 hours is usually 70% to 90% of its final 3. Zinc
strength 4. Palladium
Ans: 4 5. None of the above
Ans: 4
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(KCD)

3. physical properties of the cement film may be

556. Ductility can be measured by? impaired
1: reduction in area at the fractured end 4. cement will be highly soluble in oral fluids
2. cold bend test Ans: 2
3: elongation after ftracture
4. all of the above
5. none of the above
Ans: 4

557. All of the following slow down the setting

reaction of gypsum products except?
1: dried blood
2. borax
3. sodium citrate
4. 30% sodium chloride
5. 4% sodium sulfate
Ans: 5

558. All of the following are accelerators of the

setting reaction of zinc oxide Eugenol, except?
1. acetic acid
2. water
3. zinc acetate dihydraie
4. calcium chloride
5. Boroglycerin
Ans: 5

559. Room temperature vulcanization (RN)

silicones are
1: condensation polymerizing silicones
2. addition polymerizing silicones
3. polyether elastomers
4. polysulfide elastomers
Ans: 1

560. The pure form of gold used in dentistry is

1. Type II gold
2. cohesive gold
3. Type lll casting gold
4. noncohesive gold
5. gold used for making palatal bars
Ans: 2

561. A thick mix of zinc phosphate cement is not

indicated for luting restorations, as the
1: mix will be highly acidic
2. restoration will not seal properly
562. For a successful metal-ceramic restoration, both the metal and porcelain must have closely
matched
1: solidification shrinkage
2. specific gravity
3. coefficient of thermal expansion
4. compressive strength
Ans: 3
563. Syneresis and imbibition are inherent properties that affect the dimensions of
1: silicones
2. impression compounds
3. reversible hydrocolloids
4. polysulfide rubbers
5. irreversible hydrocolloids
Ans: 5
564. All of the following properties of waxes depend upon temperature, except
1: creep
2. flow
3. solidification shrinkage
4. coefficient of thermal expansion below 85° F
5. plastic deformation
Ans: 1
565. The liquidus temperature of an alloy is the temperature at which the
1: last liquid solidifies
2. first solid begins to form
3. first solid begins to liquefy
4. last solid begins to form
Ans: 2
566. When taking the impression of an edentulous arch, the impression compound should be softened
1. in an electric oven
2. over a gas flame
3. in a water bath
4. in an autoclave
5. in a dry heat oven
Ans: 2
567. Internal porosity due to the boiling of the monomer is usually present on the surface of a
denturebecause the exothermic heat can be conducted away from the surface of the resin to the
investingmedium.
1. Both the statement and reason are correct
2. Both the statement and reason are wrong
3. The statement is correct but the reason is wrong
4. The statement is wrong but the reason is correct
Ans: 4