Enamel Caries Flashcards
what is dental caries
progressive destruction of tooth structure
how is dental caries initiated
by microbial activity at tooth surface
crown or exp root
what does the enviro do dental caries
dept on enviro
can progress unhindered to pulp
can remineralise
what does dental plaque dept on
plaque bac
time
substrate
susceptible tooth
what is erosion
acid demin/dissolving teeth away not same as caries as source acid of this erosion is dietary acid, saliva buffers this
what is abrasion
mechanical wear with other materials
cervical notches worn away due to tooth brush abrasion something else from enviro wearing tooth
what is attrition
mechanical tooth on tooth wear
occlusally and ncisally
grinding teeth wear
happen naturally also have approximal attrition shorten arch
what is abfraction
bite tooth slightly flexes, not flexible cause micro cracks which wear and weaken
what is the acidogenic theory
many organisms can produce acid from fermentation of sugar
many oral bac prod lactic acid
what is the prism unit
prism core - centre
prism sheath - periphery
what is the prism core
centre
tightly packed hydroxyapatite
little inter crystalline spaces
what is the prism sheath
less well packed crystals
space contains water and inorganic mat - enamelling
where does demineralisation start
prism sheath periphery
what is the clinical appearance of enamel caries
white spot lesion
clean teeth and dry teeth
matt appearance
what does the histology depend on appearance
refractive index of mounting medium
penetration of medium
what is the RI air
1
what is the RI enamel
1.62
what is the RI water
1.33
what is the RI of Quinoline
1.62 lare molecule
what are the lesion zones from the advancing front
translucent
dark
body lesion
surface zone
what is the translucent zone
1st carious change loss 1-2% mineral 50% cases few large pores due to loss of prism periphery penetrated byquinolone - appears structure less/translucent - quinolone fills prism periphery
what is the dark zone
dark brown with quinolone 90-95% lesions porosity 5-10% consists of large or small pores demineralisation and remineralisation occurring
what is the body of lesion
largest part and centre of lesion
25-50% porosity
enamel relatively translucent
strait retzius obis
what is the surface zone
relatively intact thick highly mineralised high F porous protected redeposit of mineral dissolved from deeper layers
should u probe a carious lesion
no
what is arrested caries
remineralised
changes in enviro - plaque control F, altered diet
can be brown - stain
hat are some of dentine defence mechanisms ag caries
reactionary tertiary dentine
sclerotic blocking tubules
if there is rapid progression of dentine caries what is seen
no sclerosis
odontoblasts die
possibly reparative tertiary dentin
wat is the advancing front of dentine caries
some of demineralised dentine
acid demineralisation
no bacteria
what si the zone of bacterial penetration
bac in tubules
lateral spread via branched tubules
lactobacilli
what is the zone of destruction
mixed bac pop
proteolytic enzymes
destroys organic matrix
dentine can also be describe in a simpler 2 zones method
outer superficial zone
inner deeper zone
what is the outer superficial zone
highly infected
irreversible demin dentine
proteolytic degradation of collagen matrix
what si the inner deeper zone
dentine reversibly attacked
collagen matrix not severely damaged
minimally infected
potential to repair
what are some points on occlusal caries
fissures
2 lesions
hard to detect
widening lesion
