DAO 2
Terms
undefined, object
copy deck
-
95 inorganic
1 organic - enamel
- organic matric of enamel
-
=proline
mainly protein -
begins -DEJ
extends-outer surface of crown - enamel rod
- rods/crown
- 5-12 million
- flare out from DEJ
- rods increase in diameter
- oldest enamel
-
DEJ
under cusp/cingulum - 96 mineralized
- enamel
- inorganic matter =
- hydroxyapatite
- histo X-sec of Enamel=
- translucent bc high inorganic
- with time inorganic content of enamel
- increase
- selectively permeable membrane
-
enamel
allows water/ions to pass via osmosis - formed in increments by ameloblast
- enamel rod
- traverses uninterrupted thru enamel
- rod
- alternating light/dark lines in enamel that begin at DEJ
- hunter schreger bands
- end before reach E
- hunter schreger bands
- begins at future cusp
- enamel formation
- lines retzius
- ameloblasts retreat in incremental steps
- neonatal line
- division btw enamel formed before birth/after birth
-
tiny valley on tooth surface
cirucumferentially around crown - perikymata
-
hypocalcified enamel rods
project from DEJ into enamel proper -
enamel tufts
fxn unknown - pain receptors
- enamel spindles
- elongated odontoblastic processes
- enamel spindles
-
defects in the enamel
looks like cracks/fx
-traverse entire lenght of crown from surface to DEJ - enamel lamellae
-
organic material
provide area for bacteria to enter - enamel lamellae
-
elongation >
differentiation >
deposition of D >
depostion of E - histogenesis
- elongation of
- inner enamel epi of enamel organ
- differentiation
- odontoblasts
-
cellular interaxns btw
epithelial/mesenchymal components of tooth germ - tooth dev
- rope like fibers in periph of pulp
- korff fibers
- formation/dev of tissues in body
- histogenesis
-
elongation
differentiation
deposition of D
deposition of E - histogenesis of tooth
- elongation >
- inner enamel epi cells
- elongation influences
-
mesencymal cells on periph of dental papilla to differentiate >
odontoblasts - differentiation>
- odontoblasts
- tooth dev=
- cellular interaxns btw epi and mesenchymal of tooth germ
- ectomesenchyme influences oral epi >
- epi grows down into ectomesenchyme > tooth germ
-
rope like fibers in periph of pulp
a/w formation of dentin matrix - korff fibers
- layers of enamel organ
-
OEE
IEE
stratum intermedium
stellate reticulum - cell > ameloblast > E
- IEE
- essential to initiation of D formation once E is formed
- IEE
- lateral to IEE
- stratum intermedium
- essential to enamel formation
- stratum intermedium
- central core of enamel organ
- stellate reticulum
- after enamel formation all of enamel organ >
- reduced enamel epi
- enamel and epi come together as tooth in mouth erupts
- dentoging jxn
- dental pulp from
- dental papilla
- mesodermal tissue
- dental papilla
- communicated with PDL
- apical foramen
- pulp proper=
- central zone
- nerves/BV
- pulp proper
- like cell rich zone
- pulpal core
- contains fibroblasts
- cell rich zone
- capillary nerve plexus
-
zone of Weil=
cell free zone - plexus of raschkow
-
zone of weil
cell free zone -
next to :
predentin
mature dentin - odontoblastic layer
-
70 inorganic
20 organic
10 water - dentin
- organic substance in dentin
- collagen
-
more mineralized than
cementum
bone - dentin
- calcium hydroxyapatite
- mineral phase
- mineral phase=
- inorganic matter
- dentin like
- bone
- main cell type of dentin
- odontoblast
- odontoblast from
- ectomesenchyme
- harder than bone
-
dentin
enamel - lower modulus of elasticity
-
dentin
=more flexible - cellular component
- dentin
- dental papilla >
-
dentin
pulp -
avascular
calcified - dentin
- greatest abundance in tooth pulp
- fibroblast
- newly erupted tooth
- pulp is large
- physiological process of differentiation
- bell
-
initiation
bud
cap
bell
appositional
maturation -
odontogenesis
tooth dev - induction
- initiation
- initiation
- 6th wk
- initiation stage=
-
interaxn
epi and mesenchyme>
dental lamina - proliferation
- bud stage
- 8th week
- bud
- growth of dental lamina 10 buds/arch
- bud stage/prolif
- bud stage> mesenchyme prolif>
- shape of tooth
- enamel organ starts to form
- bud stage
- prolif and differentiation
- cap stage
-
morphodifferentiation
histodifferentiation> - cap stage
- 9th-10th week
- cap stage
- tooth germ complete
-
end of cap stage=
initiation
bud
cap
bell
appositional - differentiation to its fullest extent
- bell
- enamel organ
- bell
- 4 different cell types
- bell
- cuboidal
- OEE
- columnar
- IEE
- star shaped
- stellate reticulum
-
dental papilla >
1-outer cells
2-cental cells - bell stage
- dental sac
- bell
- dental sac >
- increase in collagen
- 11-12th wk
- bell
- deposit the specifif dental tissue
- appositional stage
- takes 2 yrs to complete
- maturation stage
- dental pulp fxn
- form dentin
- odontoblasts >
- dentin
- mesenchyme >
- dentin pulp
- pulp capping good for kids bc
-
1-apical foramen large
2-more odontoblasts
3-very vascular
4-less fibrous
5-more tissue fluid - lack a collateral circulation
- young pulp
- cementum fxn
- rough surface anchorage for attachment of sharpey's
- terminal portions of principal fibers of PDL
- sharpey's
- bone like rigid CT
- cementum
- compensates for loss of tooth surface due to occlusal wear by apical deposition
- cementum
- reparative fxn
- cementum
-
collagen fibers
cellular components - cementum
- periph layer of dev cementum that is uncalcified
- cementoid
- coronal 2/3 of root
- acellular
-
contains cementoblasts
fibroblast form PDL
cementoclasts - cellular cementum
- apical 1/3
- cellular cementum
- thickest to compensate for attritional wear on occlusal
- cellular cementum
- response to irritants >
- reparative dentin
-
attrition
erosion
abrasion
dental caries
trauma >>>>> - reparative dentin
- aging
- sclerotic dentin
- dentin tubules calcified/obliterated
- sclerotic dentin
- forms initial shape of tooth
- primary dentin
- deposited before completion of APICAL FORAMEN
- primary dentin
- dentin that is formed after completion
- secondary dentin
- regular uniform layer of dentin around pulp cavity
- secondary dentin
- sharp change in direction of dentinal tubules
-
jxn btw
primary/secondary dentin -
perip layer of dentin
first layer of dentin depositted - mantle dentin
-
adjacent to
DEJ
CEJ - mantle
- korff fiber
- mantle
- circumpulpal dentin
- remaining dentin
- lines each dentinal tubule
- peritubular dentin
- more mineralized than intertubular dentin
- peritubular dentin
- surrounds peritubular dentin
- intertubular dentin
- less mineralized
- intertubular dentin
- imperfectly calcified matrix
- interglobular dentin
-
btw
calcified globules
near periph of dentin - interglobular dentin
- tomes fiber
- cytoplasmic cell process of odontoblast
- each dentinal tubule contains
- tomes fiber
- coagulated cytoplasmic processes of dentinal tubules
- dead tracts
- aging process of dentinal tissue
- dead tracts
-
caused by
caries
erosion
cavity prep
odontoblastic crowding - dead tracts
- remnant of enamel formation
- DEJ
- first layer of dentin formed >
- ameloblasts enter first formative state
- secrete enamel matrix as retreat away from DEJ
- ameloblasts
- begin dentin formation immediately before enamel formation
- odontoblasts
- odtontoblasts lay down a collagen matix
- dentinogenesis
- move from DEJ inward towards pulp
- dentinogenesis
- adjacent to pulpal surface
- new layer of dentin
- calcification of tooth begins
- DEJ
- morphology of DEJ determined at
- BELL stage
- free nerve endings
- only type of nerve ending
-
myelinated
unmyelinated - pulp
- pulp nerves
-
afferent
sympathetic - sensory=
- myelinated
- motor
- unmyelinated fibers
- not found in pulp
- proprioceptors
- decrease reticulin fibers>
- aged pulp
- secondary/tertiary dentin >
- aged pulp
- increase collagen fibers
- aged pulp
-
denticles
pulp stones - aged pulp
- lie within PDL
- cementicles
- fused with cementum
- cementicles