histopathology of caries

Question 1

what things leave in early carious lesion

Answer 1

calcium
phosphate
carbonate

Question 2

what helps remineralization

Answer 2

saliva
calcium
phosphate
carbonate
fluoride
pH control

Question 3

does enamel erupt fully mineralized? y/n

Answer 3

yes

Question 4

enamel breakdown by % by weight

Answer 4

95% mineral, 5% water

Question 5

enamel consist of what

Answer 5

hydroxyapatite

Question 6

enamel is derived from what

Answer 6

ectodermal component

Question 7

enamel is formed by what

Answer 7

ameloblast (lost as tooth erupts)

Question 8

is enamel vascular and cellular

Answer 8

it is avascular and acellular, cannot be regenerated

Question 9

enamel structure organization

Answer 9

rods (prism) and interrod enamel (interprismatic substance)

Question 10

enamel is build from closely packed and long, ribbon like and separated by neighbor by what spaces

Answer 10

carbanatoapatite crystals
tiny intercrystalline spaces

Question 11

crystal dimensions (width and thickness) and what symmetry

Answer 11

60-70nm in width, 25-30 nm in thickness
hexagonal symmetry

Question 12

hydroxyapatite formula

Answer 12

Ca10(PO4)6(OH)2

Question 13

what else does enamel consist of

Answer 13

carbonate, sodium, fluoride

Question 14

hydroxyapatite knoop hardness number

Answer 14

430 KHN

Question 15

enamel knoop harndess number

Answer 15

370 KHN

Question 16

ranking of hardness

Answer 16

enamel > dentin = cementum > bone

Question 17

dentin derived from what original

Answer 17

mesenchymal

Question 18

what quality of dentin prevents fracture of enamel

Answer 18

elastic

Question 19

Dentin breakdown

Answer 19

70% inorganic (HA in form of small plates)
20% oranic (90% collage (type I, III, V), proteins and lipids)
10% water

Question 20

critical pH of enamel

Answer 20

5.5

Question 21

critical pH of dentin

Answer 21

6.2

Question 22

critical pH of enamel changes to what w fluoroapatite

Answer 22

4.5

Question 23

what was used to show dentin is permeable

Answer 23

H2O2

Question 24

what is the protected area

Answer 24

area on tooth surface where dental plaque is allowed to accumulate undisturbed by mechanical forces days and weeks

Question 25

1 week change

Answer 25

increase porosity 20-100um deep (microscopically) dissolution of outer enamel surface increase in intercrystalline spaces

Question 26

2 week change

Answer 26

enamel changes visible after air-drying further increase in enamel porosity

Question 27

3-4 weeks

Answer 27

whitish opaque change chalky change visible w/o air drying subsurface lesion starts to form extensive loss of mineral beneath the outer surface

Question 28

white spot lesion surface zone mineral loss

Answer 28

<5% mineral loss

Question 29

white spot lesion surface body of lesion mineral loss

Answer 29

5-30% mineral loss

Question 30

white spot lesion dark zone mineral loss

Answer 30

2-4% mineral loss

Question 31

white spot lesion translucent zone mineral loss

Answer 31

1% mineral loss

Question 32

relative protection against dissolution of outer enamel what dimension

Answer 32

10-50um

Question 33

what protein is rich in the saliva that helps prevent breakdown

Answer 33

proline

Question 34

white spot to cavitation timeline

Answer 34

1-2 week ultrastructural 3-4 weeks white spot then cavitation

Question 35

what does sclerotic dentin do

Answer 35

make dentinal tubules smaller so acid cant enter (defense mechanism)

Question 36

reactive dentin helps protect

Answer 36

pulp

Question 37

what shape is the smooth surface enamel lesion

Answer 37

board area of origina, conical or pointed extension towards DEJ V shape from external enamel to DEJ

Question 38

what is an integral part of the pulpodentinal organ

Answer 38

odontoblast

Question 39

what is teh most common defense mechanism

Answer 39

tubular sclerosis, which is deposition of mineral along and within the dentinal tubules, resulting in gradual occlusion

Question 40

outer lesion

Answer 40

bacteria penetrated, most of structure lost to demineralization produced by bacterial acids

Question 41

turbid inner lesion

Answer 41

no bacteria present lost peritubular dentin and the intertubular dentin mostly demineralized

Question 42

transparent inner lesion

Answer 42

retains peritubular dentin and the tubule may be partially filled w minerals (whitlockite crystals)

Question 43

sub transparent inner lesion

Answer 43

presents granular-shapped crystals and normal dentin is found beneath

Question 44

what does the inner lesion consist of

Answer 44

turbid, transparent, sub-transparent

Question 45

when may varying inflammatory reactions be seen in the subodontoblastic regions

Answer 45

when demineralization approaches the pulp between 0.5-1mm

Question 46

for pulp reactions, the inflammatory cell reactions are the result of what

Answer 46

bacterial byproducts

Question 47

if bacteria invade the pulp, acute inflammatory response is created with what

Answer 47

neutrophil leukocyte accumulation

Question 48

composition of root surface

Answer 48

70% inorganic 20% organic 10% water

Question 49

do early lesions on root surfaces appear as white spots

Answer 49

no

Question 50

root surface caries factors

Answer 50

root exposed poor oral hygiene xerostomia salivary gland hypofunction dietary habits location (plaque retentive areas)