Dentin Pulp Complex II Flashcards
What is the endgame of dentistry?
KEEP THE PULP HAPPY
What is the dental pulp?
Living, highly cellular core of the tooth
What is the primary cell type of the pulp?
Fibroblasts
—Maintain pulp matrix
*Next most numerous are the odontoblasts
The dental pulp arises from>
ECTOMESENCHYMAL
—Dental papilla
What does the pulp do>
Support the mineralized components of the tooth
Includes:
- Blood vessels
- Innervation
- Fibroblasts
- Immune cells
- Progenitor cells for replacement and repair
What are the 4 histological zones of the pulp from outer to inner?
OD Layer
Cell FREE Zone of Weil
Cell RICH Zone
Pulp Core
The extracellular matrix of the dental pulp is comprised of 2/3rds what and 1/3rd what?
2/3rds - Collagen III
1/3rd - Collagen I
T/F - With age, collagen content increases, and fibrils aggregate into larger bundles, with the greatest concentration apically.
TRUE
The ground substance of the pulp is made of what 3 things?
Proteoglycans
Glycoproteins
Water
*On a non-mineralized collagen matrix
What are odontoblasts (ODs)?
POLARIZED cells
Elongated nucleus at the pulpal side of cell
Secretory components (Golgi bodies) —Toward the dentinal side
ODs form a layer of cells held together by what?
Junctional complexes
ADHERANS JUNCTIONS, NOT ZONULAR
ODs can form gap junctions with what?
Pulpal fibroblasts
Fx of ODs?
Creation and maintenance of dentin
Supported by the rest of the pulp
Collagen and non-collagenous protein production and secretion
Key growth factors
Vesicular release from the OD process forms peritubular dentin
T/F - Tertiary dentin has NO tubules.
TRUE
What do fibroblasts do?
Support odontoblasts and help to hold things in place
Produce and maintain the supportive matrix of the pulpal tissue
Where are fibroblasts found?
Pulp core and cell rich zone
What are the dental pulp progenitor cells?
Mesenchymal progenitor cells present in the pulp
They are recruited to form new odontoblast-like cells in response to the dentin
—Involved in reparative dentin formation
Tell me about the immune cells in the pulp.
Macrophages
IL-1beta, TNFalpha
Dendritic cells
What is the vascular supply to the pulp?
Arise from external carotid aa and sup/inf alveolar aa
T/F - 4-8 arterioles/root access the pulp thru the apical foramen.
TRUE
Progression: Arterioles, capillaries, venules
Capillaries present in the cell free zone
Tell me about the lymphatic supply to the dental pulp.
Drain vascular exudate, and interstitial fluid out of the pulp
- Lymph flow is equal to arterial interstitial flow
- Lymphatic vessels have thinner walls, epithelial lining, and thin smooth muscle layer
T/F - The pulp is highly innervated by nerve (nociceptive nerve endings).
TRUE
T/F - Nerve fibers branch out thru the coronal pulp, forming the PLEXUS OF RASCHKOW.
TRUE
In the root pulp, are there plexuses of RASCHKOW?
No
-Branches of nerve fibers
Incoming nerve fibers consist of afferent nerves from the _________, and sympathetic branches from the ______ _______ ________.
Trigeminal
Superior cervical ganglion
Nerve bundles consist of what 2 types of axons?
Alpha-delta - myelinated
C - unmyelinated
T/F - Myelination decreases as fibers proceed toward the coronal pulp.
TRUE
T/F - Some unmyelinated nerves pass into the tubules and are closely associated with odontoblasts.
TRUE
Walk me thru the chart on slide 17.
Infection/breakdown of matrix -Vasculature, immune cells, nerves —Progenitor cells —-Fibroblasts —-Odontoblasts
Fibroblasts lead to pulp matrix repair
Odontoblasts lead to tertiary dentin
What are the 3 models of dentin sensitivity?
Direct innervation
Odontoblast nociception
Tubule fluid conductance
What are pulp stones?
Mineralized tissue formed inappropriately in the pulp
-True
—Tubules and OD-like cells (rare)
-False
—Atubular mineralized tissue, sometimes with necrotic tissues at the center
Why does the pulp recede as we grow older?
Secondary dentin formation
-Reduction in cell number
Tell me more about age related changes in pulp.
Decrease in pulp permeability (peritubular occlusion), but more brittle teeth
Loss of nerve axons, decrease in sensitivity
