ORAL BIOLOGY Flashcards
DESCRIBE ENAMEL
an epithelial product, translucent, hard, brittle, non-vital
what is the makeup of an enamel prism
this is the basic unit of enamel (microscopically) - there is a CORE which is tightly packed and a SHEATH which is loosely packed. (packed hydroxyappatite crystals)
describe the meaning of aprismatic
this is the last and first formed enamel, it has NO PRISMS
what is the job of the gnarled enamel at the cusps of the teeth
provides strength as that is where most of the load is eg masrticatory force!
where the direction of the enamel prisms point out towards?
the PDL
enamel spindles are extensions of what?
they are extensions of dentinal tubules
what are the perikymata
these are the inward bumps
pickerill ridges
the outward bumps
enamel is best developed at where on the tooth
the cusps
what are the striae of retzius
incremental growth lines, if these are accentuated it means that there is a sign of illness etc etc
what are the different lesion zones of enamel caries
translucent zone, dark zone, body of lesion, surface zone
describe what happens at the translucent zone in enamel caries
it is the 1st carious change, few large pores, prism loss structure
what happens at the dark zone of enamel caries
quoline cant penetrate, demineralisation and remineralisation occuring here
what is happening at the body of the lesion in enamel caries
largest part of the zones and it is translucdent
surface zone - what is happening here in enamel caries
intact, highly mineralised
describe what happens to arrested enamel caries
there may have been a diet change, good plaque control, fluoride varnish placed. these are usually brown and wide
describe what happens during occlusal caries in enamel
due to the fissures in the teeth, these are usually hard to detect, 2 lesions whcih follow the prism direction.
describe dentine
collagen matrix, specialised connective tissue, strong and hard, tubules
describe dentine
collagen matrix, specialised connective tissue, strong and hard
what is in dentinal tubules
can depend in which direction they go, we can have no cells only dentinal fluid, can have odontoblasts or odontoblasts AND nerves
we can have primary curvature dentine tubules following onto what…….
secondary curvatures, within these we have lines of owen (following the curvatures)
what do the collagen fibres play a role in within dentine
these run parallel to the ADJ and provide STRENGTH! - they also show the incremental lines of von ebner
what are the 3 classifications of dentine
1) developmental dentin, 2) primary secondary and tertiary dentine, 3) peri and inter tubular dentine
describe developmental dentine
2 parts = mantle - this is the 1st formed, adjacent to enamel, large collagen fibrils
2nd is circumpulpal - this makes up the REST of dentine, small collagen fibrils
