MCQs on Oral Histology - Dentin Part 4

# S-Shape of dentinal tubule is due to:
A. Incremental deposition
B. Peritubular dentin
C. Crowding of odontoblasts
D. Due to excess amount of organic component

# The formation of which of the following does not represent normal physiological process of dentin formation?
A. Primary and secondary dentin
B. Secondary dentin and Circumpulpal dentin
C. Tertiary dentin and Sclerotic dentin
D. All of the above

# All of the following is true about dentinal tubules except:
A. Inner pulpal layer contains more dentinal tubules than outer dentin layer
B. The diameter of dentin tubules ranges from 5 to 7 micrometer
C. The diameter of dentinal tubule is more at pulpal layer than outer layer
D. The bonding is more difficult is more difficult on the inner layer of dentin compared to outer surface

# Fluid flow , in and out of the dentinal tubules is proportional to the tubule diameter by:
A. Third power of the diameter
B. Sixth power of the diameter
C. Square of the diameter
D. Fourth power of the diameter

# The average diameter of coronal dentinal tubules near the pulp is :
A. 0.2-0.5 microns
B. 2-3 microns
C. 0.2-0.3 microns
D. 7 microns

# In adult teeth , the type of dentin present underlying dentino-enamel junction is:
A. Predentin
B. Mantle dentin
C. Interglobular dentin
D. Tertiary dentin


# All are the factors governing dentin permeability except:
A. Smear layer
B. Fluid Convention
C. Length of Dentinal tubules
D. Diffusion coefficient

# The most accepted theory for dentin sensitivity is :
A. Transduction theory
B. Direct neural stimulation
C. Hydrodynamic theory
D. Hydrostatic theory

# Compared to intertubular dentin , peritubular dentin is characterized by which of the following ?
A. Greater stainability
B. Lesser content of the inorganic salts
C. Greater content of the inorganic salts
D. Greater content of large collagen fibers

# One of the following statement is unique about circumpulpal dentin :
A. Collagen fibers are oriented perpendicular to DEJ
B. Von Korff fibers are present
C. Contain Phosphophoryn
D. Requires matrix vesicle for mineralisation

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MCQs on Oral Histology - Dentin Part 3

# Formula of hydroxyapatite crystal is :
A. Ca3(Po4)2.CaCO3
B. 3Ca3(Po4)2. Ca(OH)2
C. CaPo4. Ca(OH)2
D. None of the above

# The type of dentin that is formed prior to root completion is :
A. Inter tubular dentin
B. Peritubular dentin
C. Circumpulpal dentin
D. Secondary dentin

# Accentuated incremental lines in dentin due to disturbances in matrix and mineralisation process is:
A. Incremental lines of Retzius
B. Incremental lines of von Ebner
C. Contour lines of Owen
D. None of the above

# The pain transmission through dentin is :
A. Direct neural stimulation
B. Fluid or hydrodynamic theory
C. Transduction theory
D. All of the above

# Which of the following is correct ?
A. Reparative dentin is characterized by having fewer and more twisted tubules than normal dentin and may include odontoblasts
B. Dead tracts appear black in transmitted and white in reflected light
C. Sclerotic/transparent dentin appears transparent or light in transmitted light
D. All of the above


# First formed dental tissue :
A. Enamel
B. Dentin
C. Cementum
D. Bone

# Dentinal tubules are calcified in:
A. Sclerotic dentin
B. Secondary dentin
C. Primary dentin
D. Interglobular dentin

# Dentin formed throughout the life is:
A. Sclerotic dentin
B. Secondary dentin
C. Repartive dentin
D. All of the above

# Regarding teeth which statement is wrong ?
A. Enamel is harder than dentin
B. Enamel has no cells
C. Ameloblast secrete enamel and dentin
D. Odontoblast produce dentin

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MCQs on Oral Histology - Dentin Part 2

# The dentin receptors are unique because:
A. They elicit pain to hot and cold
B. They elicit pain to touch and pressure
C. They elicit pain to chemicals
D. Elicit only pain as a response

# The main bulk of dentin is formed by :
A. Peritubular dentin
B. Mantle dentin
C. Inter tubular dentin
D. Predentin

# The zone of dentin most recently formed and uncalcified is known as:
A. Mantle dentin
B. Circumpulpal dentin
C. Predentin
D. Secondary dentin

# Inter globular dentin results due to:
A. Failure of coalescence of calcospherites
B. Fracture of the dentin
C. Artifact in light microscopy
D. Disturbance in dentinal tubules

# Dentinogenesis by odontoblasts first behins at :
A. Pulpal end
B. Cusp tip
C. Tooth bud stage
D. Cervical area


# Sclerotic dentin has following features :
A. Caries susceptible
B. Insensitive
C. Hypersensitive
D. Resistant to caries

# The microhardness of dentin is about:
A. 1/2 that of enmel
B. 1/7 that of enamel
C. 1/4 that of enamel
D. 1/5 that of enamel

# Shape of the crown and the size of the roots is determined by:
A. Pulp
B. Dentin
C. Enamel
D. Cementum

# Physically and chemically, the dentin is closely related to:
A. Bone
B. Acellular cementum
C. Enamel
D. None of the above

# Organic portion can be separated from the mineral by :
A. Incineration / Organic chelation
B. Decalcification
C. Devitrification
D. Combustion

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MCQs on Oral Histology - Dentin

# Dentinal tubules are :
A. Concave
B. Straight
C. S-Shaped
D. None of the above

# The cells that form secondary dentin are:
A. Cementoblasts
B. Fibroblasts
C. Odontoblasts
D. Osteoblasts

# Dead tracts in ground section appears as:
A. Dentinal tubules
B. Coarse fibril bundles arranged at right angle to the dentinal surface
C. Black in transmitted light and white in reflected light
D. White in transmitted light and dark in reflected light