MCQs on Dental Materials - Restorative Resins


# 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?
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?
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:
B. CO2
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%

Dental Material MCQs - Gypsum Products

# 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

Procedures undertaken in preventive orthodontics are all EXCEPT:

 # Procedures undertaken in preventive orthodontics are all EXCEPT:
A. Parents education
B. Checkup for oral habits
C. Extraction of supernumerary teeth
D. Space regaining

The correct answer is D. Space regaining. 

Procedures of preventive orthodontics: 
1. Parent education 
2. Caries control 
3. Care of deciduous dentition 
4. Management of ankylosed tooth 
5. Maintenance of quadrant wise tooth shedding timetable. 
6. Checkup for oral habits and habit-breaking appliances if necessary. 
7. Occlusal equilibration if there are any occlusal pre-maturities. 
8. Prevention of damage to occlusion, e.g. Milwaukee braces 
9. Extraction of supernumerary teeth 
10. Space maintenance 
11. Management of deeply locked first permanent molar 
12. Management of abnormal frenal attachments 

Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of:

 # Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of:
A. Simple anchorage
B. Reciprocal anchorage
C. Stationary anchorage
D. Intermaxillary anchorage

The correct answer is C. Stationary anchorage. 

An anchor tooth or source, which does not move against the forces of teeth to be pulled is stationary
anchorage. In a real sense, only the extraoral source of anchorage derived from headgear would be a stationary anchorage. The anchor tooth being housed in a bioactive environment would show some degree of movement and hence cannot be classified as a stationary anchorage in a real sense.

Bone can be induced to grow at surgically created sites by the method called:

 # Bone can be induced to grow at surgically created sites by the method called:
A. Osteogenesis
B. Distraction osteogenesis
C. Bone wax
D. Green stick fracture

The correct answer is B. Distraction osteogenesis.

• Distraction osteogenesis is the method of inducing bone to grow at surgically created sites. 
• Russian Surgeon Ilizarov discovered in 1950's that if cuts were made through the cortex of a long bone of the limbs, the arm or leg then could be lengthened by tension to separate bony segments. 

• Currently it is believed that best results are obtained if this type of distraction starts after a few days of initial healing and callus formation and if the segments are separated at a rate of 0.5 - 1.5 mm/day. 

• Also this technique is employed for lengthening of mandible and inducing maxillary growth by separating cranial and facial bone at their sutures. 

Perspiration and redness of the cheek and ear after eating

 # A 58-year-old woman underwent left superficial parotidectomy for a pleomorphic adenoma 2 years ago. She presents with complaints of occasional perspiration and redness of the left cheek and ear after eating. Which of the following nerves is the most likely source of these complaints? 
A. Great auricular
B. Frontal branch of the facial nerve
C. Auriculotemporal
D. Lingual

The correct answer is C. Auriculotemporal.

The auriculotemporal syndrome is an unusual phenomenon, which arises as a result of damage to the auriculotemporal nerve and subsequent reinnervation of sweat glands by parasympathetic salivary fibers.

The patient typically exhibits flushing and sweating of the involved side of the face, chiefly in the temporal area, during eating. The severity of this sweating may often be increased by tart foods. Of further interest is the fact that profuse sweating may be evoked by the parenteral administration of pilocarpine or eliminated by the administration of atropine or by a procaine block of the auriculotemporal nerve.

Reference: Shafer's Textbook of Oral Pathology, 7th Edition.

The diameter of the tip of a periodontal probe is:

 # The diameter of the tip of a periodontal probe is:
A. 0.25 mm
B. 0.5 mm
C. 0.75 mm
D. 1 mm

The correct answer is B. 0.5 mm.

Periodontal probes are used to measure the depth of pockets and to determine their configuration. The typical probe is a tapered, rodlike instrument calibrated in millimeters, with a blunt, rounded tip. There are several other designs with various millimeter calibrations. The World Health Organization (WHO) probe has millimeter markings and a small, round ball at the tip. Ideally, these probes are thin, and the shank is angled to allow easy insertion into the pocket. Furcation areas can best be evaluated with the curved, blunt Nabers probe. When measuring a pocket, the probe is inserted with a firm, gentle pressure to the bottom of the pocket. The shank should be aligned with the long axis of the tooth surface to be probed. Several measurements are made to determine the level of attachment along the surface of the tooth.

Reference: Carranza's Clinical Periodontology 12th edition.

Which of the following may create gingival deformities that require gingivoplasty to eliminate the defects?

 # Which of the following may create gingival deformities that require gingivoplasty to eliminate the defects?
A. Erosive linchen planus 
B. Desquamative gingivitis 
C. Acute herpetic gingivostomatitis 
D. Necrotising ulcerative gingivitis 

The correct answer is D. Necrotising ulcerative gingivitis.

■ Shelf-like gingival margins after healing may result in plaque accumulation. 
■ The gingiva is reshaped with periodontal knife or with electrosurgery. This process of eliminating the defects by reshaping is called as gingivoplasty. 
■ Gingival deformities are seen in gingival disease:  (Asked in AIIMS 1999) (ANUG) 
Surgical procedure for severe tissue destruction in ANUG infection is:  (Asked in COMED 2011) (Reshaping the gingiva, Gingivoplasty) 

Site of Antidiuretic hormone (ADH) action is:

 # Site of Antidiuretic hormone (ADH) action is:
A. Proximal tubule
B. Loop of Henle
C. Vasa recta
D. Collecting tubule

The correct answer is D. Collecting tubule.

Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular fluid hypertonicity (hyperosmolality). AVP has two primary functions. First, it increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Second, AVP constricts arterioles, which increases peripheral vascular resistance and raises arterial blood pressure.

Acute increase of sodium absorption across the ascending loop of Henle. This adds to the countercurrent multiplication which aids in proper water reabsorption later in the distal tubule and collecting duct.

Pyruvate dehydrogenase complex contains all EXCEPT:

 # Pyruvate dehydrogenase complex contains all EXCEPT:
A. Biotin
D. Co-A

The correct answer is A. Biotin.

Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate.

The enzymes involved in PDC are Pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2), and Dihydrolipoyl dehydrogenase (E3). The cofactors involved are: TPP (thiamine pyrophosphate), magnesium, lipoate, coenzyme A, FAD and NAD+. 

The benign neoplasm of ‘brown fat’ noted in oral/pharyngeal region is:

 # The benign neoplasm of ‘brown fat’ noted in oral/pharyngeal region is:
A. Lipoma
B. Hibernoma
C. Teratoma
D. Brown tumor

The correct answer is B. Hibernoma. 

Hibernomas are uncommon neoplasms of brown adipose tissue. The most frequent sites of occurrence include the thigh, shoulder, and back. Less common myxoid and spindle cell hibernoma variants are likely to be located in the posterior neck and shoulder. Hibernomas are benign lipomatous neoplasms and have no potential for malignant transformation.  Hibernomas contain brown fat, and the name was coined about the presence of brown fat in hibernating animals. First described by Merkel 1906, these tumors are similar to lipomas in clinical behavior but have unique imaging and histopathologic features. Hibernomas generally present in young adults with a mean age of 38. In summary, these tumors are:

  • Composed of brown fat
  • Represent benign neoplasms
  • Generally well-circumscribed masses
  • Generally are small in size
  • Exhibit slow growth
  • Histopathologically composed of brown fat cells
  • Chief differential diagnosis include well-differentiated liposarcomas (WDLS)
  • Most often involve the thigh, trunk, and chest.
  • Rare locations seen in less than 10% of cases include retroperitoneal, thorax, and intraabdominal regions.
  • Fewer than 20% are intramuscular in location.

Reference: Tafti D, Cecava ND. Hibernoma. [Updated 2023 May 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:

SNA angle describes the relationship of the:

 # SNA angle describes the relationship of the:
A. Maxilla to the cranial base
B. Mandible to the cranial base
C. Maxilla to mandible
D. Maxilla to the upper incisors

The correct answer is A. Maxilla to the cranial base. 

SNA: the angle between the sella/nasion plane and the nasion/A plane (normal value at the end of growth 82 ± 2°). This angle assesses the antero-posterior position of the maxilla relative to the upper cranial structures.

Analysis of skull shape and size, supraorbital ridge, extension of zygomatic arch beyond external meatus, measurement of angle of mandible helps in:

 # Analysis of skull shape and size, supraorbital ridge, extension of zygomatic arch beyond external meatus, measurement of angle of mandible helps in:
A. Sex determination
B. Racial determination
C. Age determination
D. Ethnicity determination

The correct answer is A. Sex determination.

Skull and facial features like mastoid process, supraorbital ridges, size and architecture of skull can help in determining the sex of patient in 94% cases. 

Sex differentiation (Sexing) of a specimen: It can be done using methods as below: 

 Using craniofacial morphology: The following 6 traits give accurate results 94% times: 
- Mastoid process 
- Supraorbital ridge \
- Size and architecture of skull 
- Extension of the zygomatic arch beyond the external auditory canal 
- Nasal aperture and 
- Gonial angle (on the mandible) (Including more features increases accuracy by 2%) 

Prolonged retention is usually needed in:

 # Prolonged retention is usually needed in:
A. Diastema
B. Mild crowding
C. Anterior cross bite
D. Deep bite

The correct answer is A. Diastema.

Fixed (bonded) orthodontic retainers are normally used where intra-arch instability is anticipated and prolonged retention is planned. There are three major indications:
• Maintenance of lower incisor position during late growth
• Diastema maintenance
• Maintenance of posterior tooth position in adults

Reference: Proffit's Contemporary Orthodontics, 6th Edition.

Root shape before and after orthodontic treatment with radiographic evidence was first given by:

 # Root shape before and after orthodontic treatment with radiographic evidence was first given by:
A. Kaley and Phillip
B. Newman and Proffit
C. Ketcham AH
D. Malmgren and Lavendar

The correct answer is C. Ketcham AH.

Albert H. Ketcham was born on August 3, 1870, and grew up in Whiting, Vermont. He graduated from the Boston Dental School in 1892, then moved to Colorado due to ill health. Inspired by the challenges
of the young profession of orthodontics, he chose to enter the Angle School of Orthodontia in 1902. As a deep thinker with an inquiring mind, Ketcham explored many of the philosophical and mechanical
problems, as well as the controversies of the profession of his day. He was one of the first to investigate root resorption, which continues to be a challenge today. He began to question some of Angle’s arbitrary pronouncements, causing Angle to attack him vehemently as a deviationist. He was smart enough to travel his own way from that time on. He worked hard to improve the American Society of Orthodontists (ASO) and served as their president in 1929. He was also instrumental in founding the American Board of Orthodontists (ABO), serving as its first president. In recognizing his lifetime of service, the Albert H. Ketcham Memorial is made to the individual member annually in recognition
of contributions made to the art and science of orthodontics. This award was meant to perpetuate and inspire the member as a leader in orthodontics following the example set by Dr. Ketcham. 

He pioneered dental radiography and was the first US orthodontist to install an x-ray laboratory. He delivered the first paper on x-rays in orthodontics to the American Society of Orthodontists in 1910. In 1926 he presented the first comprehensive data on root resorption.46 Although the earliest mention of root resorption in permanent teeth goes back to 1856, it was a report by Ketcham in 1927 (followed by a second in 1929) that finally aroused the concern of orthodontists.

Reference: ORTHODONTICS Current Principles and Techniques, Lee W. Graber, 7th Edition.

Non caseating granuloma with bilateral Hilar lymphadenopathy is a feature of:

 # Non caseating granuloma with bilateral Hilar lymphadenopathy is a feature of:
A. Histoplasmosis
B. Sarcoidosis
C. Silicosis
D. Tannosis

The correct answer is B. Sarcoidosis.

Sarcoidosis is described as a multisystem granulomatous disease of unknown origin characterized by the formation of uniform, discrete, compact, non-caseating epithelioid granulomas. It is more common in blacks than in whites. Though many investigators have regarded this disease, of unknown etiology, both infective and noninfective agents have been implicated. Currently the infectious etiology is more favored with focus on Mycobacterium and Propionibacterium. It is interesting to note that there was a belief that sarcoidosis is in some way related to tuberculosis. The factors which stood against were inability to culture the bacteria from the pathological tissues and difficulty in identifying them in stained sections.

Reference: Shafer's Textbook of Oral Pathology 7th Edition.