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19 Cards in this Set
- Front
- Back
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What is in the pulp
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fibroblasts, collagen
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When are enamel forming cells lost?
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as tooth erupts
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when are the root and apical foramen completed
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2-3 years after eruption
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enamel
physical? Vascualr? Permeable? Regenerate? Remin? |
-96% HA
-Little organic material which surrounds enamel rods -Hard but brittle -Avascular -Permeable to acids/bacteria -no Regenerating -Some remin |
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Undermined Enamel
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Need to remove enamel not supported by dentin
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Dentin
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70% HA-softer
Odontoblast in adjacent pulp -->send processes into dentinal tubules -carries persist faster due to d-tubes -innervated via nerves in pulp -yellow -As long as pulp is present, new dentin can form |
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Why is Dentin sensitive
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Hydrodynamic Theory
-Layer of fluid which is present in dentinal tubules transmits changes in temperature and osmotics to nerves |
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Dentin-Pulp Complex
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Both come from Neural Crest Cells
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Progression of carries, dentin vs. enamel?
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carries widen in dentin due to tubules and softer material
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Pulp histology
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-Loose Ct w/ collagen fibers
-extensive vacularity -axons of sensory neurons(cell free zone) -fibroblast, odontoblasts, WBCs, undifferentiated msenchymal cells |
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Dentin-Pulp Complex in Injury
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Primary Dentin: all teeth have, no repairative potential
2ndary Dentin: produced during occlusion Tertiary: Reparative! |
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Primary Dentin
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fromed during tooth development priory to closure of apical foramen
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Secondary dentin
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formed post eruption after closure of apical foramen
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Reparative/tertiary
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Formed in response to injury
-->older age = smaller pulp cavity, more dentin due to constant occlusion |
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Cementum
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65% HA
Fibrous Matrix Embedded in Sharpey's Fibers of PDL(b/w cementum and bone) |
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Acellular/primary cementum
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Acelluar/primary: first layers deposited at DCJ, No cementocytes, thickness never increases
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Cellular/secondary cementum
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Additional layers deposited over acellular cementum primary at apical 1/3 of root.
Retains cementoblasts so thickness can increase |
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Hypercementosis
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a repair response of cellular cementum
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Repair Potential
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Enamel: some remin
Cementum: cellular cementum can increase thickness Dentin: odontoblast make new dentin and undifferentiated mesenchyme-->odontoblast Dentin best anidate but difficult to generate entire structure as different origins and hard to make similar shape. |
