Free Dentine and Pulp MCQs with Answers

• A. 0.4 mm
• B. 0.3 mm
• C. 0.2 mm
• D. 0.7 mm

Explanation: The average apical foramen diameter in adult maxillary teeth is approximately 0.4 mm.

• A. 32
• B. 50
• C. 52
• D. 62

Explanation: A complete dentition contains 32 permanent teeth and 20 primary teeth, giving 52 pulp organs in total when each tooth is counted as one…

• A. Below odontoblast
• B. Above odontoblast
• C. In radicular pulp
• D. In pulp horn

Explanation: The cell-free zone, or Weil's zone, lies immediately beneath the odontoblast layer in the peripheral pulp.

• A. Cementoblasts
• B. Osteoblasts
• C. Fibroblasts
• D. Ameloblasts

Explanation: Fibroblasts are the most numerous cells in dental pulp and produce and maintain its collagen-rich connective-tissue matrix.

• A. Unaffected odontoblasts from the pulp
• B. Osteoblasts
• C. Histocytes
• D. Undifferentiated cells

Explanation: When the original odontoblasts are destroyed by operative injury, odontoblast-like replacement cells differentiate from undifferentiated…

• A. Loose connective tissue
• B. Vascular tissue
• C. Granulation tissue
• D. Nerve tissue

Explanation: Dental pulp is specialised loose connective tissue containing fibroblasts, extracellular matrix, blood vessels, nerves, and defence cells.

• A. Cell degenerated zone
• B. cell free zone
• C. Cell regenerated zone
• D. Cell rich zone

Explanation: Weil's zone is another name for the cell-free zone of the peripheral pulp, located between the odontoblast layer and the cell-rich zone.

• A. Nutritive
• B. Production of enamel
• C. Production of dentin
• D. Vascular supply to the teeth

Explanation: The pulp is primarily formative because its odontoblasts produce dentin throughout tooth life.

• A. Formation of dentin
• B. Nerve supply to dentin
• C. Sends impulses to CNS
• D. Nerve supply to enamel through fibres

Explanation: Dental pulp forms dentin and supplies nerves that transmit impulses from dentin to the central nervous system.

• A. Collagen fibres
• B. Haversian fibres
• C. Non-myelinated nerve fibres
• D. Reticulum

Explanation: Haversian fibres are not a component of living dental pulp, whereas collagen fibres, reticular fibres, and non-myelinated nerve fibres are…

• A. Produce alkaline phosphatase
• B. Contain collagen
• C. Are found in mantle dentin
• D. Inhibit mineralization

Explanation: Matrix vesicles are membrane-bound structures associated especially with the initial mineralization of mantle dentin.

• A. Collagen fibers are oriented perpendicular to DEJ
• B. Vonkorff fibers are present
• C. Requires matrix vesicle for mineralization
• D. Contain phosphophoryn

Explanation: Phosphophoryn is a distinctive noncollagenous protein abundant in circumpulpal dentin and essentially absent from mantle dentin.

• A. Hydrodynamic theory
• B. Direct neural stimulation
• C. Transduction theory
• D. Hydrostatic theory

Explanation: The hydrodynamic theory explains dentinal pain through movement of fluid within dentinal tubules, which stimulates pulpal nerve endings…

• A. Predentin
• B. Mantle dentin
• C. Interglobular dentin
• D. Tertiary dentin

Explanation: Mantle dentin is the first-formed layer of dentin and lies immediately beneath the dentino-enamel junction.

• A. Third power of the diameter
• B. Sixth power of the diameter
• C. Fourth power of the diameter
• D. Square of the diameter

Explanation: According to the hydrodynamic principle and Poiseuille's law, fluid flow varies with the fourth power of the tubule radius, and therefore…

• A. Primary and secondary dentin
• B. Secondary dentin and circumpulpal dentin
• C. Tetiary dentin and sclerotic dentin
• D. All of the above

Explanation: Primary and secondary dentin are normal dentin types, whereas tertiary dentin is a response to injury or irritation rather than a routine…

• A. Mantal dentin
• B. Sclerotic dentin
• C. Interglobular dentin
• D. Intertubular dentin

Explanation: Sclerotic dentin results when mineral is deposited within and partially or completely occludes dentinal tubules, reducing their…

• A. Inter tubular dentin
• B. Peritubular dentin
• C. Circum pulpal dentin
• D. Secondary dentin

Explanation: Primary dentin is completed before the root is fully formed, and its major internal portion is called circumpulpal dentin.

• A. Pulp
• B. Enamel
• C. Dentin
• D. Cementum

Explanation: Dentin forms the basic shape of the tooth and determines the outline of the crown and the size and configuration of the roots.

• A. Disturbance in dentinal tubules
• B. Fracture of the dentin
• C. Artifact in light microscopy
• D. Failure of coalescence of calcospherities

Explanation: Interglobular dentin forms when adjacent calcospherites fail to fuse during dentin mineralization, leaving hypomineralized areas between…