Dentosphere : World of Dentistry

# 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 # Matrix vesicles : A. Are found in mantle dentin B. Contain collagen C. Produce alkaline phosphatase D. Inhibit mineralization # 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 hydrodynamic theory movement of fluids in dentinal tubules cause: A. Movement of odontoblasts B. Touch the nerves of the pulp to cause pain C. Minimum effect on odontoblast D. Stimulation of odontoblastic process # Which of the areas of the tooth is most sensitive during cavity preparation : A. Enam...

# 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...

# 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. S...

# 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. Re...

# 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

# Chemico-parasitic theory of dental caries is proposed by : A. G.V. Black B. Miller C. Gottlieb D. Schwartz # Which of the following organisms is found in deep carious lesions rather than in incipient lesions ? A. Streptococci B. Lactobacilli C. Veillonella D. Bacteroides # Pioneer bacteria in dental caries are in: A. Enamel B. Dentin C. Pulp D. Cementum # The most pronounced effect on the oral microflora of a reduction in rate of salivary flow is a : A. Significant increase in number of oral bacteria B. Shift towards more acidogenic microflora C. Significant decrease in number of oral bacteria D. shift towards more aerobic microflora # Ammonia causes: A. increase in plaque formation B. increase in calculus formation C. decrease in plaque formation D. precipitation of salivary proteins # Cavity formation in a tooth, due to dental caries is due to: A. Destructive potential of Streptococcus mutans B. Destructive potentia...

# Streptococcus mutans is considered to be a principal etiologic agent of caries because it produces acid and it: A. forms a gelatinous matrix B. metabolizes substrate from saliva C. derives energy from enamel constituents D. lives symbiotically with lactobacillus # Miller put forth the acidogenic theory of dental caries in the year: A. 1890 B. 1920 C. 1924 D. 1980 # For a bacterium to be seriously considered in the etiology of dental caries, it must : A. exist regularly in the dental plaque B. produce extracellular amylopectins C. be lethal for gnotobiotic animals D. produce intracellular dextrans # Initiation of dental caries depends upon: A. formation of large amount of acid B. availability of carbohydrate food C. viscosity of saliva D. Localisation of acid over tooth surface # Caries, all are true except: A. Lactobacillus is the main causative organism in plaque B....