EX2; Pulp Flashcards
What is the embryonic origin of the dental pulp
ectoderm
neural crest ectomesenchyme
dental papilla
What are the constituents of the dental pulp
cells and cellular elements
blood and lymphatic vessels
extracellular matrix
*not calcified
What are the 5 main functions of pulp
inductive formative nutritive protective defensive/reparative
What are the two functions of the protective nature of pulp
sensory; high pressure
barrier; odontoblast junction
What are the two functions of the defensive/reparative nature of pulp
immune
formation of new dentin and pulp
What is the difference between a young pulp and an old pulp
the young pulp is much larger than the old pulp
True or False
Pulp is not normally calcified, but ectopic calcifications are common
True; these are pulp stones, typically most coronal
What becomes of calcifications in the pulp as it moves apically
the become diffuse
Where can you find diffuse calcifications
in healthy and even un-erupted teeth
True or False
Pulp stones cannot be visible radiographically
False; large dense ones can
What are the two main histologic organizations in the pulp
odontogenic zone
central (pulp) core
What makes up the odontogenic zone
odontoblast layer
cell free zone
cell rich zone
What makes up the central (pulp) core
fibroblasts
capillaries/arterioles/venules
nerves (perineural sheath)
What are the resident immune system cells found in the pulp
macrophage
lymphocytes
eosinophils
dendritic cells
What are the inflammatory immune system cells found in the pulp
plasma cells
mast cells
PMNs
These cells in the pulp detect bacterial antigens and are closely associated with the odontoblast layer
dendritic cells
These cells serve as a source for replacement of odontoblasts or fibroblasts
stem cells
What are the main components of the extracellular matrix of pulp
PGs and associates (GAGs)
glycoproteins
collagen I and III
This is involved with collagen fibrillogenesis and water retention of the ECM of pulp
PGs and other associates
This is involved in cell adhesion to the ECM
glycoproteins; fibronectin
This gives the ECM of pulp tensile strength
collagen I and III
True or False;
stem cells are only plentiful during development
False; they are also present in adults
What are the clinical implications of adult stem cells in teeth
potential source for repair or correction of genetic defects
tissue-specific stem cell populations well known in regenerating organ (blood, bone, skin)
What are the novel concepts of adult stem cells in pulp
extent of plasticity (able to become more/different)
ability to develop complex organized structures
What specific type of adult stem cells are derived from dental pulp (bone marrow, etc.)
multipotent
Dental pulp stem cells can be induced to form what
odontoblasts
adipocyte
glial-like cells in vitro
Dentin-like tissue from the dental pulp stem cells transplanted subcutaneously in immunocompromised mice what occurred
dentin-pulp complex
True or False
stem cell niches probably present in multiple location of mature pulp
True
These are the 2nd most numerous cell type in the pulp
odontoblast
What are the functions of odontoblasts
dentinogenesis
nutrients to dentin
immune
What are the different shapes of the odontoblasts coronally or apically
toward the root they become more cuboid
What becomes of the odontoblastic processes as it moves apically
they become thinner
What are the differences between the odontoblastic processes and cell bodies microscopically
the bodies contain organelles the processes contain more cytoskeletal (microtubules) elements with no nucleus or organelles
This type of junction between odontoblasts maintain position and polarity
desmosomes and adherens junctions
This type of junction between odontoblasts coordinated dentinogenesis (cell communication)
gap junctions
This type of junction between odontoblasts acts like a barrier, not allowing things to pass through
tight junctions
What was the experiment involving HRP testing looking to discover about the pulp
How strong the tight junctions of the odontoblasts were; they injected HRP into the pulp and noticed out it did not penetrate the dentin, it stopped at the odontoblast layer
What was showing involving cavity preparation and the strength of tight junctions of the odontoblasts
the cavity preparation showed to weaken those bonds, allowing HRP to penetrate the dentin
What specifically distinguished the pulp from the other tooth tissues
the presence of blood and lymphatic vessels
Blood flow in pulp is under what control
neural; sympathetic from superior cervical ganglion
sensory
What does the sympathetic nervous system control regarding the blood flow in the pulp
constricts the blood flow
alpha-adrenergic receptors
What is the importance of the lymphatic vessels in the pulp
healing; drain proteins accumulated during inflammation
Lymphatic vessels in pulp may have what in order to overcome challenge associated with encasement in hard tissue
complex anatomy
What type od nerve fibers does the pulp contain
A delta
A beta
C
These nerve fibers are sensory pain fibers
A delta
These nerve fires are sensory pain fibers and sympathetics
C
These nerve fibers are sensory pain fibers and light touch
A beta
What is the main sensation arising from activating nerve fibers innervating the pulp and surrounding dentin
pain
Innervation begins at which odontogenic phase
bell stage
Density of innervation increases until what
eruption, and probably decreases with aging
True or False
Both primary and secondary dentition is innervated
True
Nerves enter though where are termini where
enter through the apical foramen and terminate in the pulp-dentin border zone and dentin
The dye injection into pulp determined how far the nerves and odontoblast processes transported into dentin, how far was this
only about 1/3 of the way in
Where are the dentinal tubules most innervated
in the crown
This is a highly innervated region along the pulp-dentin border
Rashkow’s plexus
Nerve fibers profusely innervate what
the pulp-dentin border
What accounts for the high sensitivity of the DEJ to exposure
hydrodynamic theory
The perturbed fluid in the dentin tubule causes what to occure
neural activity
What experiment was used to support the hydrodynamic theory
premolars destined for extraction were drilled and acid-etched to open the tubules and a tube was sealed into the cavity attached to a saline-filled syringe and manometer and tested positive and negative pressure
Was the register or pain any different with negative or positive pressure
positive was slightly lower, but still produced pain
These nerve fibers are hypothesized to be pulp nerve fibers important for hydrodynamic dentinal pain
A beta (but A delta also involved)
Why are A beta fibers the ones associated with dentinal pain
they have very low thresholds for pain
The odontoblast receptor theory is highly unlikely, but how could it affect dentinal sensitivty
crowding in the tubule
non-synpatic communication possible; adhesive contacts could cause odontoblasts to “pull on” nerve fiber
True or False
Pain can arise directly from stimuli in the pulp
True
These nerve fibers have receptors for inflammatory and thermal stimuli
C fibers
C fibers are members of this family which are transmembrane receptors for thermal and inflammatory pain in regions of the body
TRP receptor
TRPA1 receptor
Sensitivity changes with what
inflammation
These are present in dentinal and pulp sensory nerves
neuropeptides
Peptides are synthesized in cell body of what
trigeminal ganglion
What occurs at the central ending of neuropeptides
transmitter function
If peptides bind with receptors on brain neurons, what occurs
pain
What occurs at the peripheral endings of neuropeptides
local regulatory function
If peptides find with receptors on vasculature/local cells, what occurs
pre-inflammatory
What four things does sensory/pain nerve also do
vasodilation (oppose sympathetics)
plasma extravasation
angiogenesis
interactions with immune cells
How does sensory/pain nerves interact with immune cells
stimulation of cytokine production by macrophages
chemotactic effects on immune cell migration
