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DR. SAMIHA J. SAMAR

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- Substantia adamantia

- Ectodermal derivative- Covers the entire

anatomical crown oftooth

- Provides contour andshape to the crown

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- Hardest tissue in thebody

- Brittle- Acellular

- Permeable

- Thickness (!microns"#$% mm&

- Color (yellowish

white"'rayish white&

- translucent

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- )* inor'anic material (hydro+yapatite)

trace minerals (strontium,magnesium, lead, fuoride)

- ,* or'anic material

water

amelogeninsenamelins

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$Enamel rods

#$-od sheath

.$/nterrodsubstance

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• Ma !ar "rom #-$%min num&er

• Has t'ree arts thebody or head0 theneck and the tail

• *ollows wavy course "rom D+J to sur"ace o"enamel

• In cross section maaear as 1sh scale,paddle shaped orma 'a!e a keyhole

pattern

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section# teeth teeth

/ncisal2occlusal !erticalo&liue same

3iddle 'oriontal same

Cervical aical 'oriontal

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- Boundary ofenamel rodand interrod

substance- 4ess calci1ed

area

- Cements or holds

to'ether the enamel rods

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- /ntertwinin' ortwistin' o"

enamel rods atincisal or cuspalre'ion

- Aids in resisting

'ig' masticatorloads wit'out"racture

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- Series o" alternatin'dark and li'htbands in t'e enamel

- Due to chan'e indirection o" t'eenamel rods

- Dar/ &ands 0

dia5ones- 1ig't &ands 0

para5ones

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- Brownish bands t'at

illustrate t'eincremental pattern o"laing down o" enamel

- 2omara&le to 'rowth

rin's o" t'e tree

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- 1ine o" boundary o" renatal andostnatal enamel(in deciduous

teet' onl)- Accentuated

incrementallines of -et5ius

- 3rominent incer!ical areas

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- 4'in, lea6ikestructures t'at

e5tends "rom enamelsur"ace towards D+Jand e!en towardsdentin

- 7r'anic in nature andhypominerali5ed

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- Aear as tufts of'rass t'at ro6ect into

t'e enamel- 7arrow ribbonlike

structure

- Hypocalci1ed enamel

rods andinterrismaticsu&stances t'atoriginates "rom D+J to

at least $8 o" t'eenamel

- 4ess minerali5ed0 wea/ened lanes

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- 89 microns t'ic/

- 3resent in all $ teet'

and :9 ; o" % teet'- 8o prism outlines

- More heavilyminerali5ed area t'an

underling enamel

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- E+ternalmanifestation o"incremental lines

o" Retius-

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- 2onca!e and !arin det' and s'ae

- Ma contri&ute toad'erence o"laue material

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- 7arrow 1ssurelikestructures w'ic' areactuall outer ed'es ofthe enamel lamellae

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- Primary enamelcuticle

- 8asmyth9smembrane

- Delicate mem&ranet'at covers theentire crown of

newly eruptedtooth

- Deri!ed "rom t'eamelo&lasts

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- 3embranapreformativa

-  :unction between

dentin andenamel

- Scalloped or has apitted aearance

- Hypominerali5ed5one

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- 4'ic/ened end o"odontoblastic process t'at crosses t'e D+J and

is entraed in t'eenamel

- Pain receptors

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- a$k$a$ Enameldroplets

- HE-S t'at &ecomesdetac'ed and

di=erentiate intoameloblasts and"orms enamel in t'e&i"urcation or

tri"urcation o" teet'

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$. +namel is incapable o" reairand relacement.

%. +namel undergoes attrition0abrasion and erosion$

8. As t'e toot' ages t'ere is loss ofrod ends and 6attenin' ofperikymata.

>. +namel &ecomes darker in color.#. +namel &ecomes lesspermeable wit' ad!ancing age.

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$ The course or direction of enamelrods is an important consideration

in cavity preparation.

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#$ Enamel isbrittle and

must besupported bysound dentin$

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.$ Presence ofdeep pits and

1ssurespredispose teethto dental caries$

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,$ ;ental lamellaeand enamel tufts

are predisposin'location fordental caries$

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%$ Enamel is permeable to6uoride and other substances$

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6. Keep the cervical surface ofenamel well polished and smooth.

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