NEW MD OPERATIVE Flashcards
what is the main component of enamel and dentin?
CHA ( carbonate substituted hydroxyapetite)
cha makes more soluble
what is critical PH of teeth?
5.5
what ph is demineralization?
below 5.5
after applying fluoride, what is the critical pH of teeth?
4.5
how long does dimenralization remineralization take?
10 minute dimeneralization
30 minutes
which ion causes dimeneralization
H+
what does MI paste due to remineralize tooth?
releases
Ca+
PO4-
3 components of how flupride works?
remineralization of tooth structure
dec. enamal solubility
interfere with caries metabolic activity
what are the pH of
Dentin and Cementum
Enamel
Enamel FA
D and C: 6.2-6.7 ( most susceptible)
enamel: 5.5
FA: 4.5
what is keyes-Jordan diagram
results of cariogenic oral flora (biofilm) with ( carbs) sugar on tooth surface overtime (host)
what is the shape of decay on smooth surface lesions?
V-shape
shape of decay on puits and fissures ??
inverted V shape
what is affected dentin?
deep, dry, leathery, demineralized decay
what is infected dentin
superficial, wet, soft, necrotic decay
dry, leathery dentin known as what?
affected dentin
T or F decay is irreversible
true
how long does it take for enamel cavitation
1-2 years
what are the steps of lesion progression to cavitation?
enamel demineralization -> dentin demineralization -> enamel cavitation (1-2 years) - > dentin cavitation
cavitation steps irreversible !!!
upon evaluation of tooth we see smooth surface is opaque white when air dried and disappear when wet
incipent !!!! reversible
what is a complex restoration?
3 surfaces MOD
what is a simple resotration
1 surface (O)
what is a compound restoration
2 surfaces MO
what is residual caries?
caries remain after tooth is prepped
what is secondary caries?
occur at junction of tooth and restoration (microleakage)
rapidly damaging decay that is light-colored, soft infectious called
chronic decay
acute decay
arrested decay
acute / fast
demineralized tooth structure that is almost remineralized is called what
chronic decay
acute decay
arrested decay
chronic / slow
what type of bacteria is in dentin?
Lactobacilus
what type of bacteria in enamel decay
strep mutans
what type of decay in root caries
actinomyces
what type of bacteria (+/-) is inenamel and what is the enzyme that helps it stick to a tooth
G+
GTF ( converts SUCROSE to glucans and fructans)
what carb in human body is mostly responsible for caries
SUCROSE
what are the salivary antibodies that fight against bacteria
sigA
what protein does saliva use to elimnate bacteria ?
GLYCOPROTEIN:
large molecules that elimante bacteria through agglutination and causes swallowing
this enzyme in saliva destroys cell walls
lysozyme
this protein in saliva activerly binds iron
lactoferrin ( iron inactivator)
caries that dissapear while wetting are caleld what?
incipient
T or F hypocalcification does not dissapear after wetting
T
a patient with 20% mineral loss comes to clinic for tooth #14. Radiographs are not showing anything. why is that?
tooth needs 30-40% loss ot be seen radiographically !!!
transillumination is used to detect what?
contact areas of anterior teeth
craze lines
fractures
a patient walks in. after examining his amalgam restoration it is found that their is a gap that is >.5 mm. does it need to be restored?
yes.
anything amalgam >.5 is deemed carious or caries- prone
amalgam looks bluish. does it need to be re-restored?
no. this is due to corrosion. it is not classified as defective.
natural tooth occluding against crown is started to become defected. what is this called>
abrasian
hypersensitivity of tooth is resukt of exposure of what?
dentinal tubules in root surface
a patient complains about sensitivty. what can you guve them to help occlude dentinal tubules?
GLUMA
what is hydrodynamic theory?
pain from dentinal fluid movement stimulates mechanoreceptors near predentin
criteria for resotring a tooth is when lesion extends where?
to DEJ !!!!
the purpose of preventitive dentistry is to encourage what?
REMINERALIZATION of incipient SMOOTH surface lesions
what is a smooth surface lesion?
lesion where there is no pits or grooves
preventitive dentistry for pits and fissures?
sealants
excavators used for what part of tooth?
enamel
dentin
calculus
dentin ( spoon)
chisels used for what part of tooth?
enamel
dentin
calculus
enamel
10-90-7-14
what does the 10 tell you?
width of blade ( 10=1mm)
10-90-7-14
what does the 90 tell you?
cutting angle
sometimes 90 is missing