The Pulp-Dentin Complex Flashcards
Four zones in pulp
-Odontoblast layer
-Cell poor zone of weil
-Cell rich zone
-pulp proper
Which layer of pulp produces dentin
Odontoblastic layer
Crown and root difference in dentinal tubules
Crown has more dentinal tubule and larger diameter
Root has less dentinal tubules and smaller diameter
What is present in cell free zone
Capillaries and unmyelinated nerve fibers passing
What happens when odontoblasts die during mechanical injury or caries
Undifferentiated mesenchymal cells from cell rich zone migrate to pulp dentin junction and differentiate into odontoblasts
Most numerous cells in pulp
Fibroblasts
Most numerous immune cells in pulp
Dendritic cells
Cells only found in inflammed pulp
B lymphocytes and mast cells
Extracellular matrix of pulp is made of
Glycoproteins
Proteoglycans
Glycosaminoglycans
Amorphous
Gel like
Supports cell
During inflammation extracellular matrix is degraded by
Inflammatory mediators and lipopolysaccharides
Difference of collagen concentration throughout the pulp
Apical portion of pulp contains more collagen than coronal portion
What stage does sensory nerve fibers appear in teeth
Bell stage
Which nerve fibers appear first
Unmyelinated C fibers
Only sympathetic fibers in pulp
Modulates circulation
When pt is having symptoms of reversible pulpitis it is by which nerve fiber
A delta it is present in pulp dentin junction. Cavity doesn’t have to be very deep to feel the pain
Irreversible pulpitis is noticed due to which nerve fibers
C fiber present throughout pulp, deep throbbing pain and has relatively deep caries
Nerve fibers in pulp are
Nociceptive
Pulpal pain is poorly localized because
Pulp does not contain propriocepters and single neuron may innervate more than one tooth
What happens to A delta fibers beneath cell rich zone
A delta fibers loose their myelin sheath and divide and form plexus- nerve plexus of Raschkow
Why does pt feel pain when lying down if pulp inflammed
Blood flow and pressure increases towards head when pt lies down that causes excessive pressure
Main inorganic component of dentin
Calcium hydroxyapatite
What type of collagen in dentin
Because it is produced by odontoblasts type I and minor amount of type III
What allows for impact of mastication to occur without fracturing enamel
The elasticity of dentin provides flexibility and works as shock absorber
Radiopacity of enamel dentin and bone
Enamel>dentin>bone
Diameters of dentinal tubule near pulp and at DEJ
Diameter of dentinal tubule is wider near pulp and narrower near DEJ
Peritubular dentin
Highly mineralized, less collagen
Predentin
First deposited unmineralized dentin, 10 to 50 micrometers and lines at innermost portion
Dentin mineralization can occur by which patterns
Globular or linear
Which type of calcification is rapid
Globular calcification pattern
Globular calcification seen in
Mantle dentin
The unmineralized dentin between the mineralized globules is called
Interglobular dentin
Which type of calcification is uniform
Linear and slow rate
Oldest dentin
Close to enamel/DEJ- mantle or primary dentin, fast rate, globular
Newest dentin- closer to pulp, secondary, slower rate, linear- lines of owen
Which area of the tooth is very sensitive
Close to DEJ because of profuse branching of dentinal tubules
Which dentin forms most of the floor and roof of pulp chamber
Secondary
Collagen fibers in dentin
Perpendicular to DEJ
2 types of tertiary dentin
Reactionary
Reparative
Continued deposition of peritubular dentin or mineralization of contents causes
Sclerotic dentin
Physiologic and pathologic dentin
Physiologic- primary, secondary, sclerotic
Pathologic- teriary
Pulp stones more commonly found in
Orifice or within root canal
