dental pulp and caries Flashcards
(31 cards)
stages of pulp
embryogensis: same as rest of tooth
begins forming in the cap stage
in the bell stage blood vessels will form
dental pulp derived from what kind of cell?
divisions?
The dental pulp consists of loose connective tissue
derived from neural crest (ectomesenchymal) cells.
Mature dental pulp is divided into two compartments
compartments of dental pulp
odontoblast layer
pulpal core
odontogenic zone laYERS
- Odontoblast cell layer
- Cell-free zone of Weil
- Cell-rich zone
- Parietal plexus of nerves (Raschkow’s plexus)
pulpal core contents
- Fibroblasts
- Type I and III collagen
- Extracellular matrix
- Blood vessels
- Nerve tissue
odontogenic zone organization
functions of pulp
- Embryonic induction
- Formative
- Protective
- Reparative
cell populations of pulp
Odontoblasts
Fibroblasts MAJORITY OF CELLS
Undifferentiated mesenchymal cells
Macrophages AND Dendritic cells= 8% of cell population
Blood vessel-related cells (e.g., endothelial & pericytes)
Neural-related cells (e.g., Schwann cells)
Lymphocytes
extracellular matrix of pulp
Collagen types I, III, IV, and V (via odontoblasts) III MOST ABUNDANT Non-collagenous matrix components: • Proteoglycans • Glycosaminoglycans • Phosphoproteins • Glycoproteins • γ- carboxyglutamate-containing proteins BMP-2, 4, and 7 FGF EGF DMP
pulp inn
branching?
function?
Pulpal innervation includes both myelinated and
nonmyelinated nerve axons.
They progressively branch, passing through the subodontoblastic layer as the parietal neural plexus (Rashchow’s plexus), on to the odontoblastic cell layer and some fibers enter into dentinal tubules.
Most nerve endings in pulp are for pain (free nerve
endings as sensory afferents from C-V) with a few
concerned with vasodilatation or constriction.
sensory afferents of pulp
Sensory afferents from the Trigeminal (C-V): • Pain • Mechanical (pressure) • Thermal (heat) • Tactile (touch)
sympathetics of pulp
from where?
Sympathetic branches from the superior
cervical ganglion are primarily vasomotor
fibers to pulpal blood vessels, concerned
for the most part, with vasoconstriction.
majority of pulpal axons
The majority of myelinated pulpal nerve axons are
A-δ (A-delta):
• Fast conducting
• Diameter in range of 1-6 μm
minority of nerve fibers in pulp
1% of myelinated nerve fibers are classified as A-β
(A-beta) fibers:
• 6-12 μm diameter
nonmyleinated fibers of pulp
Nonmyelinated fibers are designated as “C” fibers and have small diameters, ranging from 0.4 to 1.2 μm
AD and C fibers pain
A-δ fibers are associated with sharp, localized pain.
“C” fibers are associated with dull, diffuse pain.
NTs identified in pulp, functions?
CGRP/ substance P-Vasodilatation, stimulates fibroblast cell division
Epi and NE- vasconstriction
dopamine- vasoactive/ precursor to epi
endorphins- dampen nociception
each fiber of the pulp contributions to?
most branching seen?
Each fiber contributes at least 8 branches to Raschkow’s plexus.
Most terminate in the plexus as free, nonmyelinated nerve endings.
most branching is seen in the pulpal horns, decreased inn in more mineralized tissues
distribution of nn axons in intratubular dentin
most seen in lesser mineralized tissue towards to the surface (pulp horns)
less in minerlaized/apical tissues
blood vessels with same pattern
blood vessels of pulp
capillaries relative to the odontoblastic layer?
Venules have a diameter of 100 m to 150 m
Arterioles have a diameter of 50 m to 100 m
The terminal capillaries anastomose deep to the
odontoblastic layer:
capillaires of dental pulp
distribution
kinds of capillaires
Capillary loops are dense in the coronal and pulp horns
and significantly less dense in the radicular pulp
• Continuous and fenestrated capillaries and lymph vessels
are found in pulp
cholesterol with aging in pulp
With aging, blood vessels in pulp will exhibit changes such
as cholesterol plaques (atherosclerosis). If progressive
and severe, atherosclerotic plaques can result in pulpal
hypoxia due to vessel strangulation
fenestrated capillaires of pulp leakage
contribute to?
fenestrated capillaries leak serum that becomes a component of the so-called “tissue fluid”.
They also contribute to swelling and edema due to significant leakage of serum in states of inflammation.
pulpal fibrosis
possible causes
Pulpal fibrosis occurs with increasing age or persistent low-grade injury
e.g., multiple restorations in a single tooth, chronic bruxism, repeated thermal insult, etc.
