Enamel

Question 1

Enamel

Answer 1

most calcified tissue in the body, semipermeable, NOT STATIC and non-vital
mostly hydroxyapatite crystals

Question 2

What secretes the enamel matrix?

Answer 2

Tome’s process, 1 rod for 1 process

Question 3

Is Tome’s process a true process?

Answer 3

NO

Question 4

What is an enamel rod?

Answer 4

functional unit of enamel, aka prism
enamel made of millions of rods

Question 5

enamel is what kind of product?

Answer 5

ectodermal/epithelium

Question 6

Describe the makeup of enamel

Answer 6

from IEE of enamel organ, NO
collagen product, contains ameleogins (controls growth and organization of crystals)

Question 7

Where is the enamel matrix first formed?

Answer 7

incisal/occlusal part of crown near DEJ, moves to future outer enamel surface

Question 8

When does the enamel matrix mineralize to fully matured?

Answer 8

apposition and maturation stages of tooth development
mineralization continues after eruption of tooth due to deposition of minerals such as fluoride and calcium

Question 9

Gubernacular canal

Answer 9

ameloblasts becomes part of REE and create this canal for enamel cusps tip to erupt through, then tissue disintegrates

Question 10

Keyhole effect

Answer 10

each rod has head and tail end

Question 11

Crystals in head

Answer 11

parallel

Question 12

Crystals in tail

Answer 12

starts to diverge, increase masticatory strength
ameleoblasts and Tome’s process affect crystal pattern

Question 13

Where are rods thickest?

Answer 13

near cusp or incisal

Question 14

Hunter-Schreger Bands

Answer 14

curved rods due to movement of ameloblasts during enamel production, dark or light colored bands

Question 15

Interprasmatic/Interrod

Answer 15

associated with Tome’s process, different crystalline orientation, rod sheath less mineralized

Question 16

DEJ

Answer 16

scalloped, formed by basement membraned, concavity faces dentin, convexity faces enamel

Question 17

Lines of Retizus

Answer 17

incremental lines, bands of enamel rods like growth rings of tree
raised=perikymata*
lost through tooth wear

Question 18

Lamellae

Answer 18

uncalcified vertical sheets of organic material, entire width of enamel, eventually worn down, narrower and longer than tufts

Question 19

Enamel spindles

Answer 19

defects at DEJ, more prone to caries, extension of odontoblasts process of dentin into enamel

Question 20

Enamel tufts

Answer 20

defect of calcification, appear as bundles of small dark brushes, hypo calcification of enamel prisms

Question 21

What does the prism arrangement do?

Answer 21

gives direction to path of penetration for dental caries

Question 22

Smooth surface caries

Answer 22

straight line direction

Question 23

Which type of fluoride can cause fluorosis, topical or systemic?

Answer 23

systemic (during mineralization phase)

Question 24

Acid etching

Answer 24

structure of enamel allows acid to penetrate surface and leave a rough surface, allows bonding materials to adhere more easily

Question 25

Cavity preparation

Answer 25

it is important that unsupported enamel prisms are not left when removing decay and prepping cavities

Question 26

Tetracycline staining

Answer 26

if taken during mineralization phase, most notable stains in dentin, darkest near cervix

Question 27

Pits and fissures

Answer 27

less calcified area, more susceptible to caries, ameloblast become crowded between cusps and die forming weak spots, cuts off nutritional source