Histology Flashcards
Can you name of cells of the pulp?
- Odontoblasts
- Fibroblasts
- Undifferentiate mesenchymal cells
- Inflammatory cells (lymphocytes & macrophages) also (plasma cells & mast cells)
- Intercellular matrix
- Connective tissue
- Collagen = Type I, III, IV
- Vascular tissues
- Neural tissues
Can you name the five layer starting from the Dentin to the Pulp Proper?
What do undifferentiated mesenchymal cells do?
Replace irreversibly damage odontoclasts
What germ layer does the pulp originate from?
Pulp derived from cephalic neural crest - neural crest cells arise from ectoderm
What is the first type of Dentin Formed?
Mantle Dentin
What is development dentin?
Formed during tooth development
What is Circumpulpal Dentin?
- Major part of development dentin
- Intertubular dentin
- Peritubular dentin
Is Predentin mineralized or unmineralized?
Unmineralized Dentin
What is Secondary Dentin?
Physiologically formed after root development is complete
How does Tertiary Dentin form?
Response to irritation
Under the umbrella of Tertiary Dentin, you have reactionary and reparative dentin - how do they differ?
- Reactionary: Produced by original odontoblasts
- REparative: Produced by recruited underrentiated mesenchymal cells as the original odontoblasts have been destroyed
How many dentinal tubules are present at the DEJ/CEJ relative to the Pulpal Wall?
- DEJ.CEJ = 10,000 - 25,000 per sq mm
- Pulpal Wall = 30,000 - 52,000 per sq mm
What is the diamter of dentin tubles at the DEJ/CEJ relative to the Pulpal Wall?
- Diameter at DEJ/CEJ = 1 - 2 microns
- Diamaeter at Pulpal Wall = 3 - 4 microns
*Bacteria < 1 nm in diamter
What is the brakdown of dentin?
- 45% inorganic - hydroxyapatite crystals
- 33% organic - collagen and ground tissue
- 22% dentinal fluid
Can you describe the Hydrodynamic Theory?
- Exposed dentinal tubules
- Rapid fluid movement…in—out
- Caused by heat, cold, air, probing, hyper-osmotic solution
- A-delta fibers stimulated
- Result - dentinal hypersensitivity
*Inward flow of heat - outward flow - cold, air blasts; produces stronger nerve response
What are some examples of Afferent Sensory fibers of the pulp?
- A Delta
- A Beta
- C Fibers
What is an example of a an Efferent sensory fiber of the pulp?
- C: sympathetic fibers - vasoconstriction
- No proprioceptive fibers
Describe A Delta Fibers?
- Large
- Myelinated
- Quick
- Sharp
- Shooting pain
- Full formed 3 - 5 years post eruption
Describe A beta fibers…
- Myelinated, but few in #
Describe Afferent C fibers…
- Small
- Unmyelinated
- Delayed
- Dull
- Aching
- Burning Sensation
Describe the circulatory system of the pulp…
- Arterioles, capillaries, vanules
- A-V anastomoses
- Lymphatics
- Unyielding denin walls
- Irreversible Damage
- Poor collateral circulation
- Degenerative inflammation
- Lymphatics abosr the larger molecules that canno be absorbed by the capillaries
How close does a carious lesion need to be to elicit a significant increase in the extent of the inflammation?
0.5 mm
What cells make up the “chronic” reponse to pulpal inflammation?
Lymphocytes and Macrophages
Describe the pulpal response to caries…
- Inflammatory reaction preceds bacteria
- Chronic response: lymphocytes/macrophages
- “Acute response” 0.5 mm
- Edem - localized
- Microabscess
- Pressure - loalized
- Degeneration
- Pulp becomes necrotic when # of bacteria out number inflammatory response
What is the change in microbes from healthy to pathogenic?
Aerobic to Anaerobic (facultative anaerobes (can grow with or without oxygen) to obligate anaerobes (which cannot use oxygen for growth and can even be harmed by it)
What causes periapical pathosis?
Bacteria
