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 ligth C. Sclerotic transparent dentin appears transparent or light in transmitted light and dark in reflected light D. All of the above
Matrix vesicles: A. Are found in mantle dentin B. Contain collagen C. Produce alkaline phosphatase D. Inhibit mineralization
One of the following statement is unique about circumpulpal dentine: A. Collagen fibers are oriented perpendicular to DEJ B. Vonkorff fibers are present C. Contain phosphophoryn D. Requires matrix vesicle for mineralization
The most accepted theory for dentin sensitivity is: or Which of the following is the most accepted theory of transmission of dental sensation: A. Transduction theory B. Direct neural stimulation C. Hydrodynamic theory D. Hydrostatic theory
In adult teeth, the type of dentin present underlying dentin-enamel junction is: A. Predentin B. Mantle dentin C. Interglobular dentin D. Tertiary dentin
Fluid flow, in or out of the dentinal tubules is proportional to the tuble 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 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. Tetiary dentin and sclerotic dentin D. All of the above
Regarding teeth which statement is wrong: A. Enamel is harder than dentine B. Enamel has no cells C. Ameloblast secrete enamel and dentine D. Odontoblast produce dentin
Excess deposition of calcium in the dentinal tubules is referred to as: A. Sclerotic dentin B. Mantal dentin C. Interglobular dentin D. Intertubular dentin
1st formed dental tissue: A. Enamel B. Dentin C. Cementum D. Bone
The pain transmission through dentin is: A. Direct neural stimulation B. Fluid or hydrodynamic theory C. Transduction theory D. All of the above
The type of dentin that is formed prior to root completion: A. Inter tubular dentin B. Peritubular dentin C. Circum pulpal dentin D. Secondary dentin
Organic portion can be separated from the mineral by: A. Incineration/organic chelation B. Decalcification C. Devitrification D. Combustion
Shape of crown and the size of the roots is determined by: A. Pulp B. Dentin C. Enamel D. Cementum
Sclerotic dentin has following features: A. Caries susceptible B. Insensitive C. Hypersensitive D. Resistant to caries
Inter globular dentin results due to: A. Failure of coalescence of calcospherities B. Fracture of the dentin C. Artifact in light microscopy D. Disturbance in dentinal tubules
The main bulk of dentin is formed by: A. Peritubular dentin B. Mantle dentin C. Inter tubular dentin D. Predentin
Tome’s firbres are: A. With out but not with in the dentin B. Odontoblastic processes in dental tubules C. Type of sharpey’s fibres D. Originate from tome’s granular layer
Korffs fibres are seen in: A. Mantle dentin B. Secondary dentin C. Reactionary dentin D. Indeed dermal tubules
The type of tertiary dentin which contains cellular inclusions is found in: A. Sclerotic dentin B. Mantle dentin C. Predentin D. Osteodentin
The organic lining of the calcified dentinal tubules is known as: A. Lamina propria B. Lamina lucida C. Lamina limitans D. Lamina densa
The cells that form secondary dentin are: A. Cementoblasts B. Fibroblasts C. Odontoblasts D. Osteoblasts
Which of the areas of the tooth is most sensitive during cavity preparation: A. Enamel (anterior teeth) B. Enamel (Posterior teeth) C. Dentin D. Dentinoenamel junction
Transmission of stimulus across dentin is: A. Direct activation of nerve endings B. Correlated with the innervation density of the dentin C. Stimulus induced fluid flow D. There is no transmission of stimulus across dentin
During the formation of primary teeth: A. Enamel forms more cervically than dentin B. Enamel forms faster than dentin C. Dentin forms faster than enamel D. Processes of their cells remain in content with each other
Compared to the inter tubular dentin, peritubular dentin is characterized by which of the following : A. Greater stainability B. Lasser content of inorganic salts C. greater content of inorganic salts D. Greater content of large collagen fibers
All factors govering dentine permeability EXCEPT: A. Smear layer B. Fluid convection C. Length of dentinal tubules D. Diffusion coefficient
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
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 7μm C. The diameter of dentinal tubule is more at pulpal layer than outer layer D. The bonding is more on the inner layer of dentin compared to outer surface
S shape of dentinal tubules is due to: A. Incremental deposition B. Peritubular dentin C. Crowding of odontoblasts D. Due to excess amount of organic component
Dentin formed through out the life is: A. Sclerotic dentin B. Secondary dentin C. Reparative dentin D. All of the above
Dentinal tubules are calcified in: A. Sclerotic dentin B. Primary dentin C. Secondary dentin D. Interglobular dentin
Accentuated incremental lines in dentin due to disturbances in matrix and mineralization process is: A. Incremental lines of retzius B. Incremental lines of vonebner C. Contour lines of owen D. None of the above
Formula of hydroxyapatite crystal is: A. Ca3 (Po4)2 CaCo3 B. 3Ca (Po4)2 Ca(OH)2 C. CaPo4 Ca(OH)2 D. None of the above
Physically and chemically, the dentin is closely related to: A. Bone B. Acellular cementum C. Enamel D. None of the above
The microhardness of dentin is about: A. 1/2 that of enamel B. 1/7 that of enamel C. 1/4 that of enamel D. 1/5 that of enamel
Dentinogenesis by odontoblasts first begins at: A. Pulpal end B. Cusp tip C. Tooth bud stage D. Cervical area
The zone of dentin most recently formed and uncalcified is known as: A. Mantle dentin B. Circumpulpal dentin C. Predentin D. Secondary dentin
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
Mirgration of odontoblasts into dentinal tubules occurs during: A. Cavity preparation B. Dehydration C. Water irrigation D. None of the above
The dentin adjacent to the dentinoenamel junction is called the: A. Mantle dentin B. Circumpulpal dentin C. Predentin D. Secondary dentin
Which of the following dentinal layers is more mineralized: A. Peritubular dentin B. Inter tubular dentin C. Dentinal tubules D. Circum pulpal dentin
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
