test 2 cariology histology Flashcards
whats the intercrystaline space?
the space between the enamel rods that usually is filled with water.
can you feel pain in enamel?
no, theres no nerve endings
Can you feel pain in dentin?
yes,
how can dentin defend against toxins?
by forming sclerotic and reparative (tertiary) dentin
is dentin hard, stiff or flexable?
flexible
whats the process of the formation of the “white spot:?
enamel exposed to acids causes enamel crystal rod to shrink which increases the intercrystaline space which then becomes more porous. The increase in porosity causes the white spot
to see the white spot what must you remove?
the overlying plaque, it should feel matt and rough.
white spots are dissolution of the enamel surface or …..( what)
perikymata
the body of a lesion is directly under what zone?
surface zone
whats under the body of the lesion?
dark zone, this is where demineralization occurs.
is the surface zone or body porus?
the body, the surface zone remains intact and is the last to cavitate
whats a good way to remove plaque to check for lesions?
air and water, the probe is to risky. it could poke through.
do occlusal caries or smooth surface caries start narrow and widen pulpally?
occlusal, smooth surface caries start wide and thin out like a pyramid.
how does the dentin defend itself from caries?
by forming sclerotic dentin at the DEJ.
by forming reparative/reactive/tertiary dentin at the pulpal dentin border
what 2 things are occuring during tubular sclerosis?
- Deposition of mineral within the tubule due to irritation of a vital odontoblast.
- When the enamel demineralizes-there is an increase in porosity and permeability-stimulates the odontoblasts in the center of the lesion which corresponds to the highest level of biofilm activity
what happens at the DEJ and is important in maintaing a stain free DEJ?
the caries spread like crazy
from superficial to deep, name all the different histological zones
surface ,body, dark, translucent, dead tract, reactionary dentin zone
whats the surfce zone?
enamel area that is directly over the caries
whats the body zone
where the caries are
whats the Dark zone?
where active demineralization is occuring via bacteria. Has affected and infected bacteria.
whats the transulcent zone?
no bacteria, this is the first visible sign of caries, (artilieary firing infront to soften it up for the troops)
whats the dead tract zone
dentin odontoblasts are “dead” degenerated. The dentin tubule no longer has a odontoblast. (basically the bacteria worked so fast the dentin didnt have time to lay down a mineral to protect it)
whats the reactionary/ reparative dentin zone?
where teritiary dentin is layed down to protect from further damage.
besides bacteria what can cause dead tracts of the dentinal tubules?
trauma
whats the last thing to happen in the caries process?
cavitation- this is the breakdown of the outer enamel.
what happens during cavitation?
break down of enamel, biofilm gets protected within the cavity, a shift towards acid-producing bacteria, demineralization of DEJ, undermining of enamel
after cavitation whats the Zone of destruction
most superficial part of the dentin and is decomposed by the action of acids and proteolytic microorgs
after cavitation whats the zone of penetration
tubular invation of bacteria
after cavitation whats the translucent zone
demineralized dentin that is not penetrated by bacteria
whats a liquefaction foci?
when dentinal tubules are invaded by bacteria and groups of tubules coalesce
whats a transverse cleft?
destruction advances in incremental lines of growth which are at right angles to the tubules
how is sclerotic dentin and tertiary dentin helpful?
they reduce the permeability of the tubules
after becoming dead tracts, can the odontoblast come back?
yes, new odontoblasts can be formed via fibroblasts in the pulp and lay down dentin, these are the teriary dentins
inflamation of the pulp is called…
pulpitis, this will happen if the destruction of the dentin tubules continues to occur
define chronic pulpitis
a low grade long lasting stimulus
define acture pulpitis
severe sudden stimulus
if you have a carious exposure and its not taken care of what will happen
it will spread to periapical tissues causing a apical abscess.
whats reversible pulpitis
when the pain is evoked by hot, cold, or sweet simuli and is of short duration , disappearing when the stimulus is removed.
whats irreversible pulpitis
when pain lasts for hours after removal of stimulus. This may require endodontics or extraction
define necrosis
painless because all nerves are no longer iable. Once it spreads to periapical tissues new symptoms develope.
define chronic ( asympomatic) abcesses
painless, but usually will have a draining sinus tract on and off
define acute ( sympotmatic) abcess
very painfull and can raise the tooth causing occlusal tenderness. Can also have painfull swelling.
both these abscesses are….. and can be…..
cellulitis and can be life threatening
