MCQs on Dental Ceramics and Miscellaneous - Dental Materials MCQs

# According to US FDA, the machine used for taking intraoral radiographs is classified as:
A. Class I
B. Class II
C. Classs III
D. Class IV

# For airblasting of ceramic veneer, the particle size of alumina used is:
A. 25 micrometer
B. 50 micrometer
C. 75 micrometer
D. 100 micrometer

# Which is used for etching porcelain?
A. 9.6% HF
B. 1.23 % HF
C. 37% HF
D. 4% HF

# Enamel is permeable to:
A. Bacteria
B. Bacterial product
C. Retroviruses
D. Peroxidase

# Animal test to check the biocompatibility of dental materials are all EXCEPT:
A. Buehler Test
B. Implantation test
C. Ames test
D. Sensitization test

# Incorrect regarding boric oxide incorporated in ceramics is:
A. forms glass phase
B. forms a separate lattice interspersed with the silica
C. increases viscosity of the metal
D. it strengthen the surrounding structures

# Which of the following is not a natural abrasive?
A. Arkansas stone
B. Pumice
C. Tripoli
D. Rouge

# Metal oxides are added in porcelain provide all EXCEPT:
A. Strength
B. Improve bonding
C. Cosmetic
D. Impart color

# What is true for true for fixed prosthesis?
A. It is difficult to remove prosthesis when cemented with cement having maximum compressive strength and low tensile strength
B. It is difficult to remove prosthesis when cemented with cement having maximum compressive strength and low shear strength
C. Cement is weakest phase in fixed prosthesis
D. Increased thickness of cement will cause less flaw compared to small thickness

# Regarding dispersion strengthening:
A. Increasing the strength of ceramic by dispersing their matrix with the crystalline phase of same material
B. The crystalline phase works by hindering the crack propagation
C. The strengthening is due to polymorphic transformation
D. CAD/CAM procedures in these materials further decrease their surface flaws

# Porosity in porcelain can be prevented by:
A. Thoroughness of condensation
B. Rapidity of firing
C. High firing temperature
D. All of the above

# Dental porcelains are crystalline materials of:
A. Rubber
B. Organic substances
C. Glass
D. Plastic

# In method of firing:
A. a short firing period at a higher temperature
B. a large time period at a lower temperature is preferred
C. a long firing period at a very high temperature is preferred
D. a short firing period at a very low temperature is preferred

# The melting point of titanium in degree celcius is:
A. 1056
B. 1560
C. 1668
D. 1886

# Flux used in dental ceramics is:
A. Alumina
B. Silica
C. Kaolin
D. Boric oxide

# In porcelain metal elements are embedded in the matrix of:
A. Rubber matrix
B. Glass
C. Plastic
D. Resin matrix

# Porcelain denture teeth:
A. Have a higher coefficient of thermal expansion than acrylic teeth
B. Have a lower abrasion resistance than enamel
C. Should be used where the inter dental clearance is small
D. Have a higher abrasion resistance than gold

# To prevent porosity in dental porcelain, it should be baked:
A. In presence of air
B. In vacuum
C. For long period
D. Under pressure

# Condensation shrinkage of porcelain during firing depends upon:
A. Rate of arriving at firing temperature
B. Uniformity of particle size
C. Shape and size of particle
D. Type of investment used

# The first porcelain tooth material was introduced by:
A. DeChemant
B. Ash
C. Plateau
D. McClean

# Electrolyte used for plating copper dies is:
A. Ionic copper
B. Copper cyanide
C. Silver cyanide
D. Acidic copper sulphate

# Chemical method of strengthening porcelain involves:
A. exchange of aluminum and sodium ions
B. exchange of aluminum and potassium ions
C. exchange of sodium and potassium ions
D. None of the above

# Which of the following bur is used in the preparation of cavity restored with porcelain fused to metal?
A. Carbide bur
B. Diamond bur
C. Stainless steel bur
D. Diamond bur for porcelain and carbide bur for metal

# Porcelain binds to metal in PFM crown by:
A. Metallic bond
B. Mechanical bond
C. Chemical bond
D. Both B and C

# The ideal temperature of water bath for softening fluid wax is about:
A. 51 to 54 degree F
B. 51 to 54 degree C
C. 70 to 75 degree F
D. 70 to 75 degree C

# The preferred material for repair of fractured denture base is:
A. Chemically cured resin
B. Heat cure resin
C. Light cure resin
D. Vinyl resin

# Chemical tempering in porcelains is done to interrupt crack propagation by:
A. Transformation toughening
B. Dispersion of crystalline phase
C. Inducing residual compressive strength
D. All of the above

# Pyroplastic flow of porcelain is due to:
A. High temperature during glazing
B. Low temperature during glazing
C. Improper condensation
D. High firing temperature

# The most toxic form of mercury is:
A. Methyl and ethyl mercury
B. Mercury vapour
C. Inorganic mercury forms
D. Mercury sulphide

# Compared with dental alloys, ceramics show:
A. High ductility
B. High hardness
C. Low esthetic value
D. Susceptibility to brittle fracture

# Coefficient of thermal expansion of metal ceramic alloys is:
A. Same as porcelain
B. More than porcelain
C. Less than porcelain
D. More than or equal to porcelain but not less

# Machinable glass ceramic is:
A. Cerestore
B. Decor MGC
C. Infusium
D. Leucite

# Porosity in porcelain at condensation stage depends on:
A. Shape and size of particle
B. Uniform distribution of particle size
C. Number of particles
D. None of the above

# Stage recognized in the firing of dental porcelain given below. Which of stage is not correct?
A. Cold stage bisque
B. Low bisque
C. Medium bisque
D. High bisque

# The opacity in ceramics is achieved by:
A. Boric oxide
B. Copper oxide
C. Silica
D. Titanium oxide

# Which is not present in porcelain?
A. Silica
B. Feldspar
C. Calcium carbonate
D. Amorphous material

# Dicor restoration is:
A. Two colored restorations
B. Heat pressed ceramics
C. Castable ceramics
D. None of the above

# Dispersion of crystalline phase to strengthen ceramics results in:
A. dispersed porcelain
B. glazed porcelain
C. aluminium porcelain
D. all of the above

# Which of the following is not a method to strengthen ceramic restoration?
A. Three layer laminate technique
B. Stiffer supporting materials
C. Higher thermal coefficient of expansion of ceramic as compared to metal sub-structure
D. Minimize number of porcelain firing cycles

# The best tissue tolerated material for crown and bridge:
A. Highly polished porcelain
B. Highly polished acrylic
C. Highly glazed porcelain
D. Highly polished metal

# Crocus cloth is:
A. Emery
B. Garnet
C. Pumice
D. Rouge

# The maximum shrinkage during firing process in ceramics occurs in:
A. High bisque stage
B. Low bisque stage
C. Medium bisque stage
D. Fusion stage

# Which of the following is the main constituent of porcelain?
A. Feldspar
B. Kaolin
C. Quartz
D. Clay

# Super abrasive is:
A. Sand
B. Silicon carbide
C. Diamond
D. Aluminum oxide

# The main purpose of adding metallic oxides in ceramic is:
A. Color matching
B. Transparency
C. Opacity
D. None

# Porcelain is best fired:
A. In open air
B. Under air compression
C. When several layers are fired simultaneously
D. Under minimum pressure

# Greening occurring when porcelains are fired on silver free alloys may be attributed to:
A. Vaporization of silver from the walls of contaminated furnaces
B. Surface diffusion of silver from the marginal metal
C. More rapid silver diffusion in sodium containing glass
D. Silver ionization by porcelains with high oxygen potential

# For porcelain fused to metal crown, the porcelain should have?
A. High fusion expansion
B. High fusion temperature
C. Linear coefficient of thermal expansion less than that of metal
D. Linear coefficient of thermal expansion more than that of metal

# Quartz in dental porcelain is:
A. Strengthener
B. Binder
C. Pigment
D. Crack minimizer

# Opaque porcelain:
A. is feldspathic glass
B. contains opacifier like zirconium and titanium oxide
C. not used to mask the color of the cement used in placing of restoration
D. used to produce the characteristic translucence, which is an inherent aspect of the incisal edge in natural teeth

# Phenomenon in which porcelain appears different under varying light condition is:
A. Translucency
B. Refractive optics
C. Metamerism
D. Opacification

# Shrink free ceramic is known as:
A. Cerestore
B. Captek
C. IPS Empress
D. Dicor

# Lithium silicate containing crystals in ceramic crown are:
A. IPS Empress
B. Captek
C. Dicor
D. IPS Empress 2

# Porcelain bonded to metal is strong when it is:
A. Air fired
B. Tempered after firing
C. Fired under compression
D. Fired several times before completion

# Major drawback of porcelain is:
A. High compressive strength
B. Brittleness
C. Translucency
D. Hardness

# When porcelain is baked against metal, it should possess a:
A. high fusion expansion
B. high fusion temperature
C. linear coefficient of thermal expansion less than but close to that of the metal
D. linear coefficient of thermal expansion greater than, but close to that of the metal

# Clogging of an abrasive wheel with debris causing reduction of abrasive action is called:
A. Blinding
B. Buffing
C. Dressing
D. Truing

# Ceramics fired to metals are processed by:
A. Heat pressing
B. Machining
C. Sintering
D. Slip casting

# Which of the following releases single wavelength of energy?
A. QTH
B. PAC
C. LED
D. Argon LASERs