Dentin and Pulp Flashcards
what forms dentin and pulp
ectomesenchymal cells of the dental papilla
outer cells of dental papilla will become ___________ in late bell stage and form ________
odontoblasts
dentin
central cells of the dental papilla will form what
pulp
comprises bulk of tooth and protects pulp
dentin
covered by enamel
coronal dentin
covered by cementum
radicular dentin
what is the composition of dentin
70% hydroxyapatite, 20% organic material (type I collagen)
put bone, dentin, enamel, and cementum in order from hardest to softest
enamel > dentin > cementum > bone
is dentin vascular or avascular
avascular
make dentin porous
dentinal tubules
cells in the inner enamel epithelium differentiate into what
preameloblasts
preameloblasts induce outer dental papilla to differentiate into what
odontoblasts
what do odontoblasts secrete
predentin
after predentin is secreted, the ________________ between the two cell types disintegrates
basement membrane
dentin induces preameloblasts to differentiate into ____________ that secrete the enamel matrix
secretory ameloblasts
formation of dentin
dentinogenesis
what are the two phases of dentinogenesis
- apposition of matrix (secretion of predentin)
- mineralization of predentin
what is the first substance laid down by odontoblasts
predentin
is predentin calcified or noncalcified
noncalcified
predentin is mostly made of _____________
collagen fibers
odontoblast cell bodies move away from dentin to remain with the pulp
dentinogenesis
what does each dentinal tubule contain
dentinal fluid, odontoblastic process, and part of an afferent nerve axon
run from DEJ to pulp
dentinal tubules
what pattern to dentinal tubules follow
primary s shaped curve
the primary s shaped curve of dentinal tubules is more pronounced where
in coronal dentin
lines of dentin deposition in mature dentin
imbrication lines of von Ebner
what do imbrication lines of von Ebner look like
growth rings in a tree
what direction do imbrication lines of von Ebner run in
Perpendicular to dentinal tubules
imbrication lines of von Ebner are perpendicular to ____________ and parallel to __________
dentinal tubules
DEJ
many imbrication lines together
contour lines of owen
what do contour lines of owen demonstrate
metabolic disturbances
occur during trauma at birth
neonatal line
how can dentin be classified
location in general
location in relation to dentinal tubules
time of formation
what are the types of dentin when classified by location in general
coronal or radicular
what are the types of dentin when classified by location in relation to dentinal tubules
peritubular or intertubular
what are the types of dentin when classified by time of formation
primary, secondary, or tertiary
lining the walls of dentinal tubules
peritubular dentin
is peritubular or intertubular dentin more mineralized
peritubular
this dentin is located between dentinal tubules
intertubular dentin
formed during tooth development, before completion of apical foramen
primary dentin
what are the types of primary dentin
mantle or circumpulpal
outermost layer of primary dentin, adjacent to the DEJ and first to form
mantle dentin
bulk of primary dentin and innermost layer
circumpulpal dentin
formed after root formation is complete, after tooth is erupted and is functional
secondary dentin
does secondary dentin grow slow or fast
slow
secondary dentin causes a __________ in size of pulp chamber with age
decrease
formed in reaction to external insults
tertiary dentin
does tertiary dentin form fast or slow
fast
what forms tertiary dentin
odontoblasts or mesenchymal stem cells
changes in dentinal fluid are transmitted to afferent neuron axons
hydrodynamic theory
innermost tissue of the tooth
pulp
what forms the pulp
central cells of the dental papilla
what type of tissue is pulp made of
loose connective tissue
is pulp mineralized
no
pulp supports, maintains and allows formation of what
dentin
what can dental pulp stem cells become
new odontoblasts
what can pulp be divided into
coronal and radicular pulp
what is the pulp made of
fibroblasts, odontoblasts, dental pulp stem cells, and fibers
in pulp, what compromises most of the composition
fibroblasts
what part of the pulp lines the outside
odontoblasts
the dental pulp stem cells can differentiate into what
new fibroblasts or odontoblasts
what fiber types are present in pulp
collagen and reticular
what layer of pulp is closest to the dentin
odontoblastic layer
what layer is beneath the odontoblastic layer of pulp
cell free zone
what is within the cell free zone
fibroblasts, odontoblasts, nerves, capillaries, and possibly new dentin
what layer is beneath the cell free zone
cell rich zone
the cell rich zone has a rich ______________ supply
vascular
what is the innermost zone of the pulp
pulpal core
the pulpal core has an extensive ___________ supply
vascular