MCQs in RESTORATIVE DENTISTRY - PRINCIPLES OF CAVITY PREPARATION

 

# In class II cavity for inlay, the cavosurface margin of the gingival seat clears the adjacent tooth by:
A. 0.20 ± 0.05mm
B. 0.50 ± 0.20mm
C. 0.80 ± 0.35mm
D. 1.10 ± 0.45mm

# Cavities beginning in the proximal surfaces of bicuspids and molars are:
A. Class 1
B. Class 2
C. Class 4
D. Class 6

# Incipient caries consists of opaque, chalky white areas that appear when the tooth surface is dried, this is referred as:
A. white spot
B. hot spot
C. translucent zone
D. body of lesion

# Pit and fissure caries is seen in:
A. Class I
B. Class I compound
C. Class II
D. Class II compound

# Smear Layer consists of:
A. Enamel debris
B. Micro organisms
C. Dentinal chips
D. all of the above

# A butt joint is a:
A. 90° joint
B. 120° joint
C. 70° joint
D. 180° joint

# Enameloplasty is:
A. Filling of enamel fissures with amalgam
B. Elimination of shallow enamel fissures
C. Is same as prophylactic odontomy
D. All of the above

# A prepared cavity is best protected from moisture by:
A. Cotton rolls
B. Saliva ejector
C. Rubber dam
D. Paper napkin

# Retentive grooves in the proximal box of a class II amalgam cavity should be:
A. Sharp and elongated at the dentinoenamel junction
B. Round and elongated in the dentin
C. Round and short in the dentin
D. Sharp and elongated in the dentin

# The term ' Primary Prevention' means all of the following except:
A. Planning the patient's diet
B. Prophylactic odontomy
C. Topical application of fluoride
D. Extending cavity preparation to prevent Recurrence

# Infected dentine shows:
A. Both organic and inorganic components in reversible form
B. Both organic and inorganic components in irreversible form
C. Organic components in irreversible form and inorganic components in reversible form
D. Inorganic component in reversible form and organic component in irreversible form

# Deepening the pulpal floor during cavity preparation provides for:
A. Outline form
B. Retention form
C. Convenience form
D. Resistance form

# In which type of lesion 'eburnation' of the dentine is seen?
A. Acute caries
B. Chronic caries
C. Arrested caries
D. Root Caries

# In case of a deep carious lesion incomplete debridement is done to:
A. Allow secondary dentin formation first
B. To seal the cavity and create aseptic field
C. Prevent pulp exposure and allow a thin layer of a dentin to remain
D. Avoid microleakage

# Beveling of the pulpoaxial line angle of a class II cavity is done to:
A. Increase the strength of the restoration
B. Improved marginal adaptation
C. To prevent the fracture of enamel
D. To prevent the fracture of amalgam

# Restoration of a cusp using dental amalgam requires that:
A. All enamel be removed to provide bulk
B. Only the enamel be removed to conserve tooth structure
C. At least 2 mm of cusp be removed to provide retention form
D. At least 2mm of cusp be removed to provide resistance form

# What is common in class I cavity preparation for amalgam and gold inlay?
A. Buccolingually divergent walls
B. Mesiodistally divergent walls
C. Maximum depth is needed in both cases to provide sufficient thickness
D. All of the above

# In class 2 inlay preparation, How should the pulpal floor be placed in comparison with pulpal floor in amalgam class 2 preparation?
A. Deeper
B. Pulpal floor for amalgam should be placed deeper in dentin
C. Same as Amalgam
D. None of the above

# Class IV cavity:
A. Occurs on the proximal surface not involving the incisal edge of anterior teeth
B. Occurs on proximal surface involving the incisal edge of anterior teeth
C. Occurs on proximal surface involving the incisal edge of posterior teeth
D. Involves the buccal surface of Anterior and posterior teeth

# The retention for class 5 restoration are placed:
A. In mesial and distal areas
B. Occlusal and gingival area
C. In all except the axial wall
D. At expense of axial wall

# Extension for prevention is directly related to:
A. Removal of unsupported enamel on proximal surface of Class III cavity
B. Depth of the axial wall of a class III cavity preparation
C. Elimination of all carious dentin beyond average depth of pulpal wall
D. The outline form of the cavity preparation

# While preparing a Class II cavity on a maxillary first molar which of the pulp horns are likely to get exposed:
A. Mesiolingual and mesiobuccal
B. Distolingual and distobuccal
C. Mesiolingual and distobuccal
D. Distolingual and mesiobuccal

# In a class 1 cavity prepared for silver amalgam is extended to half the distance between the contact area and the fissures and the cusp tip, the direction of the buccal and lingual walls is:
A. Diverging
B. Converging
C. Parallel
D. Independent

# The reason for sealing caries during cavity preparation is:
A. To eliminate the need for eventual direct pulp capping
B. Produce an aseptic filed when pulp exposure is inevitable
C. To allow the formation of secondary dentin before excavation
D. To produce a hard surface as a foundation for subsequent restoration

# In a cavity preparation in which the remaining thickness of dentin is more than 1.5mm, the ideal base is:
A. Ca(OH)2
B. Zinc Phosphate
C. Silicophosphate
D. Glass ionomer

# The function of proximal grooves in a class II cavity is:
A. Resistance form
B. Retention form
C. Increases strength
D. Resistance and retention form

# An incipient carious lesion on an inter proximal surface is usually located:
A. At the contact area
B. Facial to contact area
C. Gingival to contact area
D. Lingual to contact area

# In an ideal restoration, gingival margin should be:
A. Below contact point but 1mm occlusal to gingival crest
B. Below contact point but at level of gingival crest
C. Below gingival crest
D. At contact point

# Gingival extension for a restoration should be:
A. At the gingival crest
B. At least 1mm above the alveolar crest
C. At least 3mm above the alveolar crest
D. Doesn't have any relation with alveolar crest height

# Resistance form of cavity preparation is:
A. Flat pulp floor
B. enough depth of the cavity
C. Restricted size of the external walls
D. all of the above

# During M.O.D. preparation one of the cusps is undermined, indicated treatment is:
A. Reduction of cusp and include in the preparation for on lay
B. Reduction of all the cusps and crown is indicated
C. Strengthened by use of Amalgam core
D. Cusp is beveled and the patient is advised not to exert force on the cusp

# Resistance form is that shape of cavity which:
A. Prevents displacement of restoration
B. permits the restoration to withstand occlusal forces
C. Allows adequate instrumentation
D. Allows the restoration to withstand occlusal forces and prevent displacement

# A dental floss is applied to the distal bow of a clamp, its function is:
A. To facilitate the removal of the clamp
B. To prevent aspiration of clamp
C. To anchor the dam as cervically as possible
D. To stabilize the damp

# Which of the following is commonly recommended procedure for debridement?
A. Citric acid
B. Hydrogen peroxide - 10%
C. Air and water spray
D. Hydrochloric acid

# The axiopulpal depth of the proximal box in class II cavity is:
A. 0.2 to 0.8 mm
B. 0.5 to 1 mm
C. 1 to 2 mm
D. 2 to 3 mm

# Purpose of cavity preparation is:
A. To receive restorating material
B. To cleanse the caries
C. To remove bacteria
D. None

# First step in removing a rubber dam is to:
A. Remove the clamp
B. Release the holder
C. Apply a water soluble Lubricant
D. Cut the interseptal rubber with scissors

# To avoid pulpal irritation below a resistant metallic restoration, the minimum dentin thickness which should remain is:
A. 0.5 mm
B. 1.5 mm
C. 1.0 mm
D. 2.0 mm

# According to Black's classification caries on lingual pits of maxillary central incisors are:
A. Class I
B. Class II
C. Class III
D. Class IV

# In a class II cavity in an incisor the retentive points are placed:
A. At the DEJ
B. In the dentin
C. In the axial wall
D. Never on labial or Lingual walls

# Inappropriate margins in restorations are corrected primarily because:
A. They retain food debris
B. Inhibit proper plaque removal
C. Disturb occlusion
D. Create Sensitivity

# The most common cause of fracture at the isthmus of class II dental amalgam restoration is:
A. Delayed expansion
B. Inadequate depth at the isthmus area
C. Inadequate width at the isthmus area
D. Moisture contamination of the amalgam during placement.

# 'Saucering" out of small pits to improve self cleansing property is called:
A. Saucerisation
B. Enameloplasty
C. Odontotomy
D. None of the above

# Mesial and distal wall of class V cavity depends on:
A. Direction of enamel rods
B. Presence of carious Lesion
C. Contour of gingiva
D. Location of contact area

# The base of class III preparation is:
A. Axial wall
B. Gingival wall
C. Facial wall
D. Lingual wall

# While preparing occlusal cavity for amalgam in mandibular first premolar, the bur:
A. Is kept absolutely vertical
B. Is tilted slightly buccally
C. Is tilted slightly lingually
D. Can be kept in any direction

# Which of the following is not a consideration for obtaining a resistance form during cavity preparation?
A. Stress patterns of teeth
B. Direction of enamel rods
C. Designing outline form with minimal extension
D. Dovetail preparation of restoration to occlusal loading

# Gingivally the depth of a class V cavity is:
A. 0.5 - 1 mm
B. 0.75 - 1 mm
C. 1-1.25 mm
D. 2-3 mm

# For cast restorations the cavity wall should have a taper of:
A. 30-45
B. 5-10
C. 2-5
D. none of the above

# In modified class III cavity restoration retention is obtained mainly by:
A. Acid etching
B. Retentive groove/slot
C. Retentive point
D. Retentive pin

# During cavity preparation, more incidence of exposure is in:
A. Class V cavity in first premolar
B. Class II mesio occlusal cavity
C. Class II disto occlusal cavity
D. Class IV cavity

# Transverse section of Class V through the axial wall is:
A. Convex
B. Concave
C. Kidney shaped
D. Straight

# The cavosurface angle for inlay cavity preparation:
A. 90 degree
B. 150 degree
C. Less than 90 degree
D. 180 degree

# Caries detection dye can stain the following except:
A. Granular necrotic tissue
B. Dry, leathery dentin
C. Reversibly denatured collagen
D. lrreversibly denatured collagen

# The modified class III preparation uses a dovetail on the lingual side in:
A. Maxillary canine
B. Mandibular canine
C. Mandibular central incisor
D. Mandibular lateral incisor

# Preparation of class I cavities for dental amalgam, direct filling gold or gold in lays have in common:
A. Occlusally diverging facial and lingual walls
B. Occlusally diverging mesial and distal
C. Occlusally converging facial and lingual walls
D. Occlusally converging mesial and distal walls

# Which of the following prevents fracture of MO amalgam:
A. Beveling of axiopulpal line angle
B. Occlusal dovetails
C. Pin retained amalgam
D. Removal of unsupported enamel rods

# The non-active carious lesion is distinguished by all except:
A. Covered by a layer of plaque
B. Soft and leathery in consistency
C. Brown or black discolouration
D. Severe pain during caries removal

# In a class III cavity in an incisor tooth the retentive points are placed:
A. At the expense of facial and lingual walls and not in dentin
B. Entirely in dentin
C. In axial wall
D. By placing a groove in the lingual surfaces

# All enamel walls of a cavity preparation must consist of full length enamel rods on
A. Affected enamel
B. Affected dentin
C. Sound enamel
D. Sound dentin

# In air-abrasive technology the abrasive particles used are:
A. Iron oxide
B. Tin oxide
C. Aluminium oxide
D. Silicon oxide

# In an early carious lesion, the first structure to show evidence of destruction is the:
A. Enamel prism
B. Cuticle
C. Interprismatic substance
D. Lamellae

# Which of the following principles of the cavity preparation is not considered much in modern methods of restorative Dentistry?
A. Extension for prevention
B. Convenient form
C. removal of the undermined enamel
D. Removal of the carious dentine

# The wall absent in class V lesion:
A. Axial wall
B. Mesial
C. Distal
D. Pulpal wall

# It is essential to lubricate dam before applying it. Which of these is NOT a suitable lubricant?
A. Shaving cream
B. Liquid soap
C. Scrub gel
D. Vaseline

# Which is the WRONG way to apply dam using a wingless clamp?
A. Put the clamp on the tooth
B. Place the dam on the tooth with fingers, and then position the clamp over it
C. Attach the dam over the clamp and frame outside the mouth, then put the assembly over the tooth using clamp holders OVER THE dam
D. Attach the dam over the clamp and frame outside the mouth, and then put the assembly over the tooth using clamp holders UNDER the dam

# When composites are given, exposed dentin should be covered with:
A. Varnish
B. Calcium hydroxide
C. Phosphoric acid
D. ZnO eugenol cements

# Dental Pulp under any restoration is best protected by:
A. Cavity liner
B. Cavity base
C. 2 mm thick dentin
D. All of the above

# Which one of the following provides most conservative approach while restoring the tooth?
A. Cast gold
B. Dental amalgam
C. Glass ionomer cement
D. Composite resin

# In cavity preparation, line angle is:
A. Union of three surfaces
B. Union of four surfaces
C. The junction of two plane surfaces of different orientation along a line
D. Internal boundary of a cavity

# The tip diameter of a 245 bur used for conventional amalgam preparation is:
A. 2 mm
B. 0.8 mm
C. 0.3 mm
D. 0.4 mm

# The total number of point angles present for Class II amalgam restorations is:
A. 4
B. 6
C. 8
D. 11

# Whenever the caries cone in enamel is larger or at least the same size as that in dentin, it is called as:
A. Residual caries
B. Recurrent caries
C. Forward caries
D. Backward caries

# What is the major difference between a class V cavity preparation for amalgam and one for composite resin by the acid-etch technique?
A. Depth
B. Convenience form
C. Position of retentive points
D. Angulation of enamel cavosurface margins

# Cervical restorations fail mostly due to:
A. Inadequate moisture control
B. Marginal gingivitis
C. Cuspal flexure
D. All of the above

# Proximal walls in a class I tooth preparation for amalgam should:
A. Converge occlusally
B. Diverge occlusally
C. Remain straight
D. Rounded

# The configuration factor ["C" factor] for an occlusal class I cavity is:
A. 2
B. 3
C. 4
D. 5

# Preventive resin restorations are indicated in ?
A. Non-cavitated pit and fissures
B. Deep caries to prevent progress of lesion
C. Cavitated fissures which require restoration
D. Wide cavity to prevent cusp fracture

# In diagnosing the carious lesions, the tooth surface is examined visually and tactilely. Which of the following is NOT considered as visual examination?
A. Cavitations
B. Surface roughness
C. Opacification
D. Softness of the tooth surface

# For gold inlays gingival margin finish line should be:
A. Shoulder preparation
B. Chamfer preparation
C. Bevel
D. Knife edge

# The base of class III preparation is:
A. Axial wall
B. Lingual wall
C. Gingival wall
D. Facial wall

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The most reliable sign of sexual maturity in girls is:

 # The most reliable sign of sexual maturity in girls is:

A. Change in voice

B. Age at first menstruation

C. Appearance of pubic hairs

D. Breast development

The correct answer is B. Age at first menstruation.

An interesting phenomenon of the last 300 or 400 years, particularly the 20th century, has been a generalized increase in size of most individuals. There has also been a lowering in the age of sexual

maturation, so that children recently have grown faster and matured earlier than they did previously. Since 1900, in the United States the average height has increased 2 to 3 inches, and the average age of girls at first menstruation, the most reliable sign of sexual maturity, has decreased by more than 1 year. This “secular trend” toward more rapid growth and earlier maturation continued in most countries throughout the 20th century (e.g., the mean age in Poland in 1982 to 1984 was 13.2 years, and 12.8 years in 1992 to 1994) but seems to be leveling off in the developed countries at present. That still means that signs of sexual maturation now appear in many otherwise-normal girls much earlier than the previously accepted standard dates, which have not been updated to match the secular change.

Ref: Proffit 6th Edition.

MCQs on Dental Materials - Restorative Resins

 

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# All of the following statements about the differences between self-polymerizing acrylic resins and heat-cured resins are true EXCEPT:
A. The former have a lower molecular weight
B. The former have higher residual monomer content
C. The former are more porous
D. The former have greater transverse strength

# In heat cure denture base acrylic resins the monomer is:
A. Methacrylate
B. Ethylmethacrylate
C. Methyl ethyl methacrylate
D. Polymethylmethacrylate

# If curing occurs at temperature more than 100°C porosity results in which area of denture?
A. Hard thick central area
B. Thin Palatal area
C. Thin area of flanges
D. Porosity is uniformly distributed



# Which of the following is an example of a composite material?
A. A filled resin
B. Colloidal silica
C. Gold alloy
D. Wax

# Use of dimethyl-P-toluidine is indicated for:
A. Thermal polymerization of acrylic
B. Chemical polymerization
C. Retarding the polymerization reaction
D. To inhibit the action of benzoyl peroxide

# Which of the following initiator accelerator system uses light activation composite?
A. Diketone-amine
B. Organic acid-metal oxide
C. Organic acid-peroxide
D. Peroxide-amine

# Acrylic (cold cure)
A. Melts at 100°c
B. Softens at 100°c
C. Still requires heat for polymerization
D. Produces heat during polymerization

# Hydroquinone is added to methyl methacrylate monomer:
A. To prevent polymerization during storage
B. To initiate release of free radicals
C. To enable polymerization reaction at room tern perature
D. All of the above

# Radio opacity to composite resins is rendered by:
A. Silica glass
B. Organic matrix
C. Barium glass and strontium glasses
D. Fluoride particles

# Cross Linking in denture base resin is contributed by:
A. Glycol dimethacrylate
B. Benzoyl peroxide
C. N-Para toluidine
D. Methyl methacrylate

# The most important disadvantage of acrylic denture base is:
A. Porosity
B. Shrinkage
C. Tooth breakage
D. Water absorption

# Porosity present in a acrylic denture is usually the result of:
A. A prolonged curing cycle
B. Lack of sufficient pressure applied to flask
C. Insufficient acrylic resin monomer
D. Prolonged bench cooling after curing

# Which of the following constituents is common in occlusal sealants, bonding agents, composite resins?
A. BIS GMA
B. Polymethyl methacrylate
C. Benzoin methyl ether
D. Silica filter

# Acrylic resins are used for:
A. Anterior restorations
B. Temporary bridges
C. Denture bases
D. All of the above

# Marginal leakage related to temperature change occurs to the greatest extent with:
A. Amalgam alloy
B. Unfilled resin
C. Composite resin
D. Direct filling gold

# To prevent porosity in self cure acrylic resin, curing should be carried in:
A. Cold water
B. Hot water
C. Under tap water
D. Under vacuum pressure

# In self-cure acrylic resin, activator is:
A. Toluidine
B. Quaternary ammonium compound
C. Benzoyl peroxide
D. Tertiary amine

# The main advantage of composites over unfilled direct filling resin is their:
A. Higher solubility in saliva
B. Lower modulus of elasticity
C. Esthetic excellence
D. Lower thermal co-efficient of expansion

# Composite resins in comparison to acrylic have:
A. Low compressive strength
B. High abrasive resistance
C. High water absorption
D. High polymerization shrinkage

# Composite has:
A. Resin
B. Filler
C. Resin and Filler
D. None

# In processing methyl methacrylate, the resin may show porosity if the flask is placed too soon. Porosity most likely occur
A. Throughout the denture
B. Near the borders
C. In the thickest part
D. On the denture surface

# Boiling point of methyl methacrylate:
A. > B.P of water
B. < B.P of water
C. Equal to BP of water
D. Is at normal room temperature

# Polymerisation of heat-cured methyl methacrylate is initiated by:
A. Tertiary amine
B. Benzoyl peroxide free radical
C. Hydroquinone
D. Methyl ether

# Which of the following is present in the powder of the acrylic resin?
A. Methyl methacrylate
B. Benzoyl peroxide
C. Hydroquinone
D. D-methyl paratolouidine

# Subsurface porosity is due to:
A. Thermal changes
B. Thickness of the resin
C. Lack of temperature
D. Packing past the dough stage

# Light cure system, side effect is:
A. Iritis
B. Cataract
C. Conjunctivitis
D. Retinal damage

# If resin is packed in sandy stage what will be seen in the processed denture?
A. Distortion
B. Porosity
C. Inhomogeneous colour
D. Increased strength

# Bonding of composite resins to tooth structure is by:
A. Covalent bond
B. Ionic bond
C. Mechanical
D. Vanderval forces

# Which one of the following is used as filler in composite resins?
A. Quartz
B. Silica
C. Zinc particles
D. Aluminium

# The type of spatula used to mix composite is:
A. Plastic
B. Stainless steel
C. Iron
D. None of the above

# The chemical used to etch enamel is:
A. Zinc oxide
B. Methyl methacrylate
C. Phosphoric acid
D. Eugenol

# Benzoin methyl ether in a polymer indicates that they may be cured in the presence of:
A. UV light
B. Visible light
C. Infrared light
D. Diketone

# Which of the following procedure is indicated to produce cross-linking in the polymerization of linear chains of acrylic:
A. Addition of grain refining agents
B. Addition of difunctional monomers
C. Increasing the amount of heat required for linear polymerization
D. Incorporation oif terminating agents

# Which of the following may result if an excessive amount of monomer is incorporated into an acrylic resin mixture?
A. Excessive expansion
B. Low impact strength
C. Excessive shrinkage
D. Excessive brittleness

# For photo-curing the composite resin, the light source:
A. Should be held at a millimeter distance from the restoration
B. Need no protection while in use
C. Will cure composite upto a depth of 5 millimeter thickness
D. Is fiber optic

# Porosity of denture base is due to:
A. Packing at dough stage
B. Curing at 160°F for 9 hrs
C. Inadequate pressure
D. All of the above

# The function of the coupling agent in a restorative resin is to allow:
A. Adhesion of resin particles
B. Bonding between filler crystals
C. Bonding between filler and resin
D. Bonding between tooth and resin

# The imperfection seen on the lingual flange of a lower denture caused by rapid heating during a curing cycle is called:
A. Localised shrinkage porosity
B. Gas inclusion porosity
C. Micro-porosity
D. Surface porosity

# No trail closure is necessary with which one of the technique during denture fabrication:
A. Compression moulding technique
B. Injection moulding technique
C. Fluid resin technique
D. Light cured technique

# The particle size in microfilled composites is:
A. 0.02 to 0.04 mm
B. 0.5 to 1.0 microns
C. 0.01 to 0.1 microns
D. 0.3 to 0.4 mm

# A material which is a mixture of two different materials and its properties are:
A. Composite
B. Complex material
C. Combined
D. Compound

# Acid-etching is done for:
A. 30 Seconds
B. 60 seconds
C. 90 seconds
D. 120 seconds

# The polymerization of self-curing resin takes place faster in:
A. Cold water
B. Hot water
C. Under pressure
D. In vacuum

# Coefficient of thermal expansion is highest for:
A. Amalgam
B. Silicate cement
C. Gold alloy
D. Acrylic resin

# Which of the following provide opacity to composite?
A. TEGDMA
B. BIS-GMA
C. Ti02
D. None

# The latest method of curing denture base resins:
A. Heat
B. Visible light
C. Chemicals
D. Lasers

# Dentin bonding agents usually contain:
A. Only Hydrophobic component
B. Only Hydrophilic component
C. Hydrophobic and hydrophilic component
D. Lyophillic and lyophobic component

# One of the claims for the superiority composite resin restoration over silicate cement restorations is that the resin restorations:
A. Prevent galvanic action
B. Are practically insoluble in oral fluids
C. Adapt to the walls of the cavity better
D. Have a higher coefficient of thermal expansion

# The advantage of unfilled methyl methacrylate is that:
A. It can be finished smoothly
B. It has a low degree of flow
C. It is non-irritating to pulp
D. Its wear resistant is high

# To cure a heat cure resin, a proper heating cycle is necessary:
A. To prevent the porosity
B. To prevent warpage
C. To prevent volume expansion
D. All of the above

# About polymerization shrinkage of composite all are true, except:
A. Polymerization shrinkage is greater if bonded surface area is lesser than unbounded surface area
B. Polymerization shrinkage is high if within the enamel margins
C. Acid etching and priming will decrease polymerization shrinkage
D. Microleakage can occur because of polymerization shrinkage

# When restoring a tooth with resin material, acid etching can do all of the following except:
A. Increase the surface area
B. Permit chemical bonding between resin and enamel
C. Create surface irregularities in enamel for better mechanical retention of resin
D. Condition the tooth surface for better wetting

# Inorganic phase of the composites aid in:
A. Increasing the mechanical strength
B. Decreasing the coefficient of thermal expansion
C. Reducing the polymerization shrinkage
D. All of the above

# For esthetic areas where high luster is required the restoration that is used usually:
A. Glass ionomer restoratives
B. Hybrid resin composites
C. Microfilled resin composites
D. Macrofilled resin composites

# Inadequate pressure application during flasking:
A. Increases vertical dimension
B. Causes teeth to be shrunken in investment
C. Causes poor quality of colour
D. Causes fracture of denture

# Which of the following absorbs maximum amount of water?
A. Microfilled resin
B. Macrofilled resin
C. Hybrid
D. Small particle composites

# The percentage of free monomer in a heat - cured acrylic resin is:
A. 3% to 5%
B. 8% to 10%
C. 0.2% to 0.5%
D. 0.6% to 0.8%

# The restoration which shows percolation and shrinkage along the margin is:
A. Composites
B. Unfilled resins
C. Amalgam
D. Polycarboxylate

# What is the disadvantage of using composites as restorative material?
A. Increased thermal conductivity
B. Decreased wear resistance
C. Decreased thermal conductivity
D. none of the above

# The commonly used laser for curing composite resin is:
A. Nd:YAG
B. CO2
C. Er:YAG
D. Argon

# Insufficient closure of the flasks during packing of denture base resin can result in:
A. Poor colour stability
B. Less polymerization shrinkage
C. Increase in vertical dimension
D. Decrease in vertical dimension

# What is the polymerization shrinkage if 3:1 powder: liquid ratio is used?
A. 6%
B. 8%
C. 10%
D. 21%

# Acrylic resins were first introduced as a denture base material in:
A. 1925
B. 1937
C. 1951
D. 1956

# Macromolecules in Dental Resin is attached by:
A. Covalent bonds
B. Sonic bonds
C. Vander Wall's Forces
D. Hydrogen Bonds

# Quartz tungsten light cure device, minimum output of energy should not be less than:
A. 300 mw/cm2
B. 350 mw/cm2
C. 400 mw/cm2
D. 450 mw/cm2

# Along with polymerisation shrinkage, one of the major disadvantages of polymethyl methacrylate as denture base resin are its poor:
A. Biological properties
B. Thermal properties
C. Mechanical properties D. Esthetic properties

# Denture acrylics contain cross-linking agents, mainly to improve their:
A. Internal color
B. Tissue compatibility
C. Surface hardness
D. Craze resistance

# The most common coupling agents are organic silicon compounds called:
A. parabane
B. ligane
C. silane
D. chelane

# The process wherein two or more chemically different monomers, each with some desirable property, can be combined to yield specific physical properties of a polymer is known as:
A. Step-growth polymerization
B. Addition polymerization
C. Condensation polymerization
D. Copolymerization

# One bottle system of adhesive resins:
A. 4th generation bonding agents
B. Separate etching step not required
C. Separate etching step is still required
D. Contains only primer

# Dentin conditioner has the following function:
A. Removes smear layer
B. Increases surface energy of dentin
C. Forms a thin resin Layer over exposed collagen fibrils
D. Helps in bonding with composite

# Most advantageous indication of acid etching is:
A. Decrease micro Leakage
B. Decrease polymerization shrinkage
C. Decrease coefficient of thermal expansion
D. Decrease porosity in resto rative material

# Residual monomer content of chemically activated resins is:
A. 0.2% to 0.5%
B. 2% to 5%
C. 0.3% to 0.5%
D. 3% to 5%

# VLC resins are also called as:
A. Microwave-activated resins
B. Tertiary amine-activated resins
C. Light activated resins
D. Heat activated resins

# The accepted polymer to monomer ratio for packing of polymethyl methacrylate resin is:
A. 3:1
B. 4:1
C. 10:1
D. 5:1

# Cold cure acrylic expand in water by:
A. 1% by volume 0.23% by weight
B. 10% by volume 0.23% by weight
C. 0.1% by volume 0.23% by weight
D. None of the above

# Etching depth after 30 sec for orthodontic bracket with orthophosphoric acid is:
A. 10 um - 20 um
B. 3 um - 9 um
C. 50 um - 110 um
D. 200 um - 250 um

# Which of the following is NOT true of polymethyl methacrylate?
A. Knoop hardness number 18 to 20
B. Tensile strength of 60 MPa
C. Density of 1.13 g/cm3
D. Modulus of elasticity of 3.4 GPa

# During polymerisation of acrylic resin, above what temperature benzoyl peroxide form free radicals:
A. 25° C
B. 37° C
C. 50° C
D. 60° C

# Etchant preferred in gel form than in liquid form:
A. Better control over placement
B. Enhance and concentrate the action of acid
C. Helps in visualization while placement
D. None of the above

# An acidic agent that dissolves the in organic structure in dentin that allows infiltration of adhesive resin is:
A. Dentin bonding agent
B. Dentin conditioner
C. Primer
D. None of the above

# In acrylic restorative materials, the pumping action of alternately imbibing and excluding fluids is termed as:
A. lmbibition
B. Percolation
C. Syneresis
D. Evaporation

# What is the wave length of visible light used for curing light cure restoration?
A. 400 - 420 nm
B. 250 - 300 nm
C. 420 - 475 nm
D. 300 - 370 nm

# True about conversion of monomer to polymer is:
A. Density changes from 1.19g/cm3 to 0.9 and volume shrinkage is 21%
B. Density changes from 1.19g/cm3 to 0.9 and volume shrinkage is 7%
C. Density changes from 0.9g/cm3 to 1.19 and volume shrinkage is 21%
D. Density changes from 0.9g/cm3 to 1.19 and volume shrinkage is 7%

# According to ADA specification number 12, dough forming time should be less than ______ min. from the start of the mixture.
A. 90 min
B. 60 min
C. 50 min
D. 40 min

# Role of plasticizer in synthetic resins in dentistry is:
A. Increase smoothness
B. To increase bulk
C. To prevent polymerisation shrinkage
D. To reduce softening and fusion temperature

# Of the light produced by quartz - tungsten - halogen, only a small percentage is suitable for curing composite resin material and most is converted into heat. How much percentage of this light is useful for curing?
A. 0.5%
B. 5%
C. 10%
D. 50%

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Dental Material MCQs - Gypsum Products

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# Model plaster (white) used to cast study models before mixing with water, is largely composed of:
A. CaO
B. CaCO3
C. (CaSO4)2. 1/2H2O
D. CaSO4.2H2O

# The product, which is obtained by calcining under steam pressure at 120-130°C or by dehydrating gypsum in the presence of sodium succinate is:
A. Alpha - hemihydrates
B. Beta - hemihydrates
C. Calcium sulphate dihydrate
D. Orthorhombic anhydrate

# Water powder ratio of dental stone and plaster is respectively:
A. 0.28 and 0.6
B. 0.6 and 0. 28
C. 0.6 and 3.2
D. 0.28 and 0.98

# Type III Dental gypsum is:
A. Class II stone
B. Densite
C. Class I stone or hydrocal
D. Model or lab plaster

# Green strength with reference to plaster means:
A. Dry strength
B. Compressive strength
C. Strength of dental stone due to green colour
D. The wet strength

# Beta hemihydrate particles absorb:
A. more water
B. less water
C. no water
D. none of the above

# Water of reaction needed to react completely with 100 g of calcium sulphate hemihydrates to convert it to calcium sulphate dihydrate:
A. 18.6ml
B. 22.2ml
C. 30.4ml
D. 45.3ml

# Powders of dental plaster and dental stone differ mainly in:
A. Solubility
B. Shelf life
C. Chemical formula
D. Particle porosity

# Plaster of paris is mixed in:
A. Plastic bowl
B. Rubber bowl
C. Glass bowl
D. Metal bowl

# Impression plaster containing potato starch is called:
A. Plaster of paris
B. Soluble plaster
C. Anti - expansion solution
D. Die stones



# Die is:
A. Impression of single tooth
B. Impression of whole teeth
C. Replica of single tooth
D. Replica of whole teeth

# Balanced stone is dental stone:
A. Which undergoes rapid expansion
B. In which accelerators or retarders have been added according to need
C. In which amount of water of hydration is controlled
D. In which the crystals are all of uniform size

# The main ingredient in dental plaster is:
A. Calcium sulphate hemihydrate
B. Calcium phosphate
C. Calcium anhydrate
D. Calcium sulphate dihydrate

# The strength of the gypsum specimen when the water in excess of that required for the hydrate of the hemihydrate is left in the specimen is called?
A. Dry strength
B. Green strength
C. Water strength
D. Compressive strength

# Accelerators and retarders are used with gypsum products mainly to control:
A. Setting time
B. Setting expansion
C. Hardness of the set product
D. None of the above

# Gypsum is used for?
A. Impressions
B. Casts
C. Die
D. Casts and Dies

# The hygroscopic technique is associated with:
A. Investment
B. Hydrocolloids
C. Amalgam
D. Silicate

# The main difference between dental stone and dental plaster is:
A. Chemical composition
B. Shelf life
C. Shape and size of particles
D. Solubility in water

# The most commonly used accelerator in gypsum product is:
A. Sodium fluoride
B. Potassium fluoride
C. Potassium sulfate
D. Aluminium sulfate

# As per ADA No. 25, minimum amount of setting expansion required for type V gypsum product is:
A. 0.05
B. 0.10
C. 0.15
D. 0.20

# Which is a gypsum product?
A. Stone
B. Plaster
C. Investment
D. All of the above

# Plaster of paris:
A. Is wet calcined hemihydrate
B. Has porous and irregular crystals
C. Is alpha hemihydrate
D. Has a W / P of 0.2

# In plaster of paris the setting time is primarily altered by:
A. Altering P / L Ratio
B. Altering temperature of mixing water
C. Speed and length of hand spatulation
D. Addition of accelerators and retarders

# Type I gypsum product is also called:
A. Impression plaster
B. Class I stone/ Hydrocal
C. Class II stone/Densite
D. Model plaster

# The beta hemihydrate of gypsum requires more water to float its powder particles because:
A. They are more regular in shape and dense
B. They are more regular in shape and highly porous
C. They are more irregular in shape and porous
D. They are more dense and prismatic in shape

# Setting of Plaster of Paris is result of:
A. Difference in solubility of CaSO4 1/2 H2O + CaSO4•2H2O
B. Reaction between CaS04 2H2O and water
C. Nucleation and growth of CaSO4.1/2 H2O crystals
D. Reaction between hemihydrate and dihydrate

# Placing cast under tap water is to be avoided as:
A. H2O interferes with hygroscopic expansion
B. H2O In hibits polymerization of dental resin
C. H2O interferes with crystallization of dihydrate
D. Gypsum is slightly soluble in water and the surface of the cast will be eroded

# Gillmore needle is used for:
A. Testing the strength of plaster of paris
B. Evaluating the setting time of plaster of paris
C. Testing the metal hardness
D. Testing the purity of noble metals

# 2 % solution of borax is used as a surface hardening agent for:
A. Casting stone
B. Dental plaster
C. Dental stone
D. Type IV gypsum

# Gypsum product having least expansion:
A. Impression plaster
B. Model plaster
C. Stone plaster
D. Die stone

# Modifiers are added to gypsum mainly to:
A. Modify setting time
B. Modify setting expansion
C. Modify strength
D. Decrease the porosity

# Most commonly used retarder in gypsum:
A. Na2SO4
B. NaCl
C. Citrates
D. K2SO4

# ADA specification number for gypsum products are described under:
A. 1
B. 4
C. 12
D. 25

# The setting expansion of gypsum products can be reduced by:
A. Increased spatulation
B. Adding potassium sulfate
C. Less water powder ratio
D. Allowing setting under water

# Finer particle size of silica:
A. Slower the hygroscopic expansion
B. Greater the hygroscopic expansion
C. Normal setting expansion
D. No setting expansion

# A rough/ chalky surface of the cast is due to:
A. Not waiting for 20 min before pouring
B. Excess wetting agent left on impression
C. Air incorporation in the mix
D. All of the above

# The function of 2% potassium sulphate in a gypsum product is:
A. To regulate the setting expansion
B. Regulate setting time
C. Acts as retarder
D. None

# Plaster mix:
A. Rapid spatulation results in decreased setting time
B. 2% potassium sulphate is accelerator
C. Citrates are retarders
D. All of the above

# The strength of gypsum products is generally expressed in terms of:
A. Tensile strength
B. Wet strength
C. Green strength
D. Compressive strength

# Water: powder ratio for class IV stone is:
A. 0.22-0.24
B. 0.24-0.28
C. 0.65-0. 70
D. 0.45-0.50

# Within practical Limits, using Less water in mixing plaster will result in a set product that:
A. Contracts
B. Is stronger
C. Is more porous
D. Is less brittle

# Increased spatulation is case of dental stone results in:
A. Increased working time
B. Increased setting time
C. Decreased setting time
D. None of the above

# In dental materials setting time is measured by which test?
A. Rockwell test
B. Cold blend test
C. Vickers test
D. Vicat needle method

# Which of the following is false regarding setting of plaster products?
A. Setting expansion increases with increase in nucleic density
B. Most accurate method of controlling setting expansion is by chair side addition of chemicals
C. Potassium sulphate is an accelerator and reduces the setting expansion
D. Maximum acceleration effect for sodium sulphate is approximately 3.4%

# Which of the following is incorrect about non-gypsum die material?
A. All impression materials are compatible with these
B. Polyester produces the most accurate dies
C. Epoxy resin dies are undersized but are used due to their higher abrasion resistance
D. Metal dies are preferable to high strength gypsum dies for captek restoration

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