Term
What percent of dentin is mineralized? Organic? Water? |
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Definition
70 % mineralized 20% organic 10% water |
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Term
What is dentin's main job? |
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Definition
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Term
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Definition
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Term
What is predentin(Mantle dentin) laid down by? |
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Definition
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Term
What is predentin initially made of? |
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Definition
collagen fibers and ground substance |
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Term
What remains behind as odontoblasts retreat away from the DEJ? |
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Definition
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Term
As more dentin is made what happens to the pulp chamber? |
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Definition
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Term
What is the only sensation we have in our teeth? |
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Definition
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Term
When does mineralization or maturation of dentin occur? |
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Definition
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Term
What are the two phases of mineralization for dentin? |
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Definition
1.primary phase 2.secondary phase |
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Term
What happens in the primary phase of mineralization of dentin? |
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Definition
calcium hydroxyapatite crystals form as globules in the collagen fibers of the predentin, they expand and fuse |
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Term
What happens in the secondary phase of mineralization of dentin? |
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Definition
new crystals form layered on the initial crystals. They expand but don't fuse completely to one another |
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Term
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Definition
areas where primary and secondary mineralization occurred, complete crystalline fusion |
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Term
What is interglobualr dentin? |
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Definition
areas where only primary mineralization occurred, less mineralized |
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Term
What are the components of mature dentin? (4) |
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Definition
1.dentin tubules 2.dentinal fluid 3.odontoblastic process 4.afferent neurons |
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Term
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Definition
extend from DEJ or DCJ to outer wall of the pulp |
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Term
What is the dentinal fluid? |
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Definition
tissue fluid surrounding the cell membrane of the odontoblastic process |
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Term
What are odontoblastic processes? |
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Definition
long, cellular extension of the odontoblasts cell body occupying the tubule |
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Term
What are afferent neurons? |
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Definition
associated with odontoblastic process, involved in pain sensation |
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Term
What are the two types of dentin? |
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Definition
1.peritubular dentin 2.intertubular dentin |
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Term
What is peritubular dentin? |
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Definition
highly mineralized, creates the wall of the tubules |
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Term
What is intertubular dentin? |
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Definition
found betweek the tubules, not as mineralized as the peritubular. |
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Term
Which type of dentin makes up the bulk of dentin? |
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Definition
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Term
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Definition
the 1st dentin formed, closest to enamel or cementum |
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Term
What is circumpulpal dentin? |
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Definition
dentin around the pulpal wall |
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Term
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Definition
forms before tooth erupts, more mineralized |
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Term
What is secondary dentin? |
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Definition
forms after eruption and throughout life, less mineralized |
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Term
What is reparitive(tertiary) dentin? |
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Definition
forms in response to injury like recession |
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Term
What is sclerotic dentin? |
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Definition
a form of tertiary dentin seen in response to chronic injusy |
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Term
WHat happens to odontoblastic process when sclerotic dentin is formed? What fills tubules? |
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Definition
it dies, substances like peritubular dentin fill the tubules |
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Term
What are inbrication lines of von Ebner? |
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Definition
incremental lines that show the daily apposition of dentin formation |
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Term
What are contour lines of Owen? |
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Definition
a number of inbrication lines that demonstrate a disturbance in formation(neonatal line) |
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Term
What is Tome's granular layer? |
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Definition
poorly calcified dentin found near the DCJ |
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Term
What changes in dentin as we age? |
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Definition
-Tubules become narrorer as deposition of peritublar dentin continues -continued deposition of secondary dentin -stimuli not transmitted as well when we get older |
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Term
What does pulp form from? |
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Definition
the central cells of the dental papilla |
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Term
What percentaage organic is pulp? |
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Definition
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Term
What is pulp's functions? |
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Definition
1.nourishment 2.sensory 3.protective(contains white blood cells) 4.formative(odontoblasts) |
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Term
What is the shape of the pulp chamber? |
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Definition
corresponds to the shape of the tooth |
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Term
Where is the coronal pulp located? |
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Definition
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Term
Where is the radicular pulp located? |
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Definition
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Term
What is the apical foramen? |
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Definition
the opening at the pulp apex |
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Term
What are accessory canals? |
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Definition
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Term
How many pulp horns do teeth have? |
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Definition
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Term
What are the most numerous types of cell in the pulp? The second most? Other types? |
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Definition
1.fibroblasts 2.odontoblasts
also have WBC's, nerves, collagen fibers |
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Term
What are the microscopic zones of pulp? (4) |
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Definition
1.odontoblastic layer 2.cell-free zone 3.cell-rich zone 4.pupal core |
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Term
How does pulp change with age? |
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Definition
pulp fills more with collagen, decreasing the amount of water, intracelular substance, and cells |
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Term
What happens to the pulp chamber and canal as we age? Why? |
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Definition
the become smaller because of secondary dentin formation |
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Term
What can develop in the pulp with age? |
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Definition
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Term
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Definition
dentin+tubules and odontogenic processes |
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