Histology 12

Front 1

Crystalline material that is hardest calcified tissue in human body

Back 1

mature Enamel

Front 2

Mature state, noted for its almost total absence of --- matrix.

Back 2

organic

Front 3

-----, surrounding -----, along with hardness of enamel, produces a cushioning effect of tooth’s differing structures = enabling it to endure pressures of -----

Back 3

Dentin, periodontium, mastication

Front 4

Mature enamel is --- inorganic (or mineralized) material, ---- organic material and ---- H2O

Back 4

96%, 1%, 3%

Front 5

Crystalline formation of mature enamel consists of mainly -------

Back 5

calcium hydroxyapatite

Front 6

calcium hydroxyapatite chemical formula

Back 6

Ca10(PO4)6(OH)2

Front 7

Enamel is ----, not renewable; therefore can be lost forever. However, it is not a static tissuebecause it can undergo ----- changes

Back 7

Nonvital, mineralization

Front 8

Radiographically enamel differences in ----- of different parts of tooth & surrounding periodontium can be noted

Back 8

mineralization

Front 9

Enamel appears more----- than dentin and pulp, both of which appear more radiolucent

Back 9

radiopaque

Front 10

What is the only part of a tooth that is seen clinically in a healthy mouth because it covers the anatomical crown?

Back 10

enamel

Front 11

Enamel is ---- in thickness in cervical areas & --- in masticatory surfaces such as at incisal/occlusal edges and cusps where impact can be greater

Back 11

thin, thicker

Front 12

Enamel of primary teeth has amore ---- crystalline form, thus appears ---- than on permanent teeth

Back 12

opaque, whiter

Front 13

Because overall shade of enamel varies in each person and possibly within a dentition, a ---- is taken when integrating tooth-colored restorative materials or artificial teeth or crowns within an individual dentition. Goal is to match with inrestorative dental work, as closely as possible, color of patient’s other teeth

Back 13

shade value

Front 14

Process of enamel matrix formation

Back 14

Amelogenesis

Front 15

Amelogenesis occurs during the ---- of tooth development

Back 15

apposition stage

Front 16

Ameloblasts produce enamel matrix from their -----

Back 16

Tomes’ processes

Front 17

Six-sided projection of basal/secretory surface of each ameloblast that faces the dentinoenamel junction (DEJ)

Back 17

Tomes’ process

Front 18

Tomes’ process is responsible for the way the enamel matrix is laid down; thus serves as a ----factor

Back 18

guiding

Front 19

Enamel matrix is first formed in ---- part of future crown near ---- = this is the ---- wave of enamel apposition, which moves to the future outer enamel surface

Back 19

incisal/occlusal, DEJ, 1st

Front 20

2nd wave of enamel apposition ---- 1st wave,and entire process then moves ---- to cementoenamel junction (CEJ). This pattern is repeated during the maturation ofenamel

Back 20

overlaps, cervically

Front 21

Wave patterns of enamel matrix formation in the crown during -----

Back 21

apposition

Front 22

After ---- are finished with both enamel apposition and maturation, they become part of -----, along with other parts of the compressed enamel organ

Back 22

ameloblasts, reduced enamel epithelium (REE)

Front 23

reduced enamel epithelium (REE) fuses with the oral mucosa,creating a ---- to allow enamel cusp tip to erupt through oral mucosa into oral cavity

Back 23

canal

Front 24

Ameloblasts are lost foreveras fused tissue ----- during tooth eruption, preventing any further enamel apposition. The tissue can become partof -----

Back 24

disintegrates, Nasmyth’s membrane

Front 25

Residue on newly erupted teeth that may become extrinsically stained

Back 25

Nasmyth’s membrane

Front 26

After the tooth erupts into the oral cavity; however, the ---- of enamel continues.

Back 26

mineralization

Front 27

This posteruptive maturation is due to a depositing of ---- such as fluoride and calcium from ---- into hypomineralized areas of enamel

Back 27

minerals, saliva

Front 28

The ----- is the basic unit of enamel; thus enamel is composed of millions of enamel rods

Back 28

enamel rod (enamel prism)

Front 29

enamel rods vary in length because---- of enamel varies in different locations of the crown area

Back 29

width

Front 30

Rods near cusps or incisal edges,where the enamel is the thickest, are quite ---- compared with those near the CEJ

Back 30

long

Front 31

Surrounding the outer partof rod bundle is the ------. Has a different crystalline orientation; therefore, it appears different from the rod core on cross sections

Back 31

interprismatic region (interrod enamel)

Front 32

Portion of enamel that discolors when teeth become stained

Back 32

interprismatic region

Front 33

Microscopic appearance of the dentinoenamel junction (DEJ) is ----, with the ---- side of the DEJ toward the enamel and --- side toward the dentin

Back 33

scalloped, concave, convex

Front 34

Incremental lines in mature enamel

Back 34

Lines of Reitzius

Front 35

Hypothesized to represent metabolic rhythm of the ameloblasts producing the enamel matrix, which consists of an active secretory work period followed by an inactive rest period during tooth development

Back 35

imbrication lines

Front 36

Thus each band on the enamel rod demonstrates the ---- pattern of the ameloblasts

Back 36

work/rest

Front 37

apronounced line of Retzius, that corresponds to the birth of the individual. It demarcates the enamel formed prenatally and afterbirth

Back 37

Neonatal line

Front 38

Grooves associated withthe lines of Retzius present on the nonmasticatory surfaces of some teeth in oral cavity

Back 38

Perikymata

Front 39

Ridges associated with Lines of Retzius that extend mesiodistally in cervical 3rd

Back 39

Imbrication lines

Front 40

Loss of enamel and other hard tissue of the tooth as result of tooth-to-tooth contact

* Mastication

* Parafunctional habits

Back 40

Attrition

Front 41

Attrition Increases with --- common in --- areas, Permanent 1st molars wear more than 2nd ; 2nd more than 3rd

Back 41

age, anterior.

Front 42

Enamel loss from friction caused by excessive toothbrushing and abrasive toothpaste

Back 42

Abrasion

Front 43

Abrasion is common in ----- areas

Back 43

facial cervical

Front 44

Loss of enamel by chemical means (acids)

Back 44

Erosion

Front 45

Erosion Does not involve ----

Back 45

bacteria

Front 46

Erosion is Commonly seen associated with:

Back 46

Bulimia

Gastric reflux

Overusing acidic drinks

Recreational drugs(meth)

Front 47

Loss of enamel caused by tensile and compressive forces during tooth flexure, which possibly occurs during parafunctional habits

Back 47

Abfraction

Front 48

“Notching”, V-shaped notch, Occurs in cerical 3rd

Back 48

Abfraction

Front 49

Demineralization, or loss of minerals, in enamel caused by acid production by cariogenic bacteria

Back 49

Enamel Loss by Caries

Front 50

Complex pit & groove patterns on occlusal surface of permanent posterior teeth can make them susceptible to ----

Back 50

caries

Front 51

Increased dental biofilm retention and weakness of enamel forming the walls of pits & grooves

Back 51

?

Front 52

All pits & grooves should be evaluated for decay
with an ----- and -----

Back 52

explorer, mirror

Front 53

Both incipient caries in pits &
grooves and on smooth surfaces are first noted in many cases clinically as a -----, with the involved enamel appearing whiter and rougher as a result of slight surface ----- of the enamel

Back 53

white-spot lesion, demineralization

Front 54

Thin, plastic (resin) protective coating placed on
pit & grooves of teeth to prevent caries

Back 54

sealants

Front 55

Posterior teeth with deep pit and groove patterns but without incipient decay should have enamel sealants placed on the occlusal surface shortly after -----

Back 55

eruption

Front 56

------ are highly effective in
preventing pit and groove caries

Back 56

Enamel sealants

Front 57

Effectiveness of dental sealants in prevention of
----- has been demonstrated in a variety of research findings covering a span of 16 years

Back 57

tooth decay

Front 58

Sealants should be applied as soon as these teeth appear in the mouth and before they have a chance to -----.
Research shows that sealants actually stop decay when placed on top of a incipient caries by sealing off the supply of ----- that cavity-causing bacteria need.

Back 58

decay, nutrition

Front 59

Photomicrograph showing the enamel rods
after acid etching, which ----- the interprismatic region of enamel surface to allow the flow of the enamel sealant into the enamel for greater ------

Back 59

demineralizes, strength

Front 60

can enter the enamel systemically
through the ----- of developing teeth, by ----- of fluoride in drops, tablets, or treated water, all of which are considered ----- methods

Back 60

blood supply, ingestion, pre-eruptive

Front 61

Fluoride can also enter ------ by direct contact on exposed teeth surfaces by ingestion of fluoridated water or professional application or directed use of prescription or over-the-counter rinses, gels, foams, chewable tablets, and fluoridated toothpastes, all of which are considered ------ methods

Back 61

topically, post-eruptive

Front 62

Excess systemic fluoride during tooth development can occur, which can occur in areas where the water naturally has a higher than normal level of fluoride
Can cause a type of enamel dysplasia, -----, with intrinsic staining, giving effected teeth a mottled ------

Back 62

dental fluorosis, discoloration

Front 63

Autoimmune disorder that can occur in
genetically predisposed people where the ingestion of gluten leads to damage in the small intestine

Back 63

Celiac Disease

Front 64

Dental enamel problems Celiac Disease Involves the ------ dentition

Back 64

permanent

Front 65

Dental enamel problems with Celiac Disease causes ------ which cause white, yellow, or brown spotson the teeth

Back 65

Tooth discoloration

Front 66

Dental enamel problems with Celiac Disease cause -----, pitting or banding of teeth,and mottled or translucent-looking teeth

Back 66

Poor enamel formation

Front 67

Dental enamel problems with Celiac Disease cause imperfections are ----- and often appear on ----- and ------

Back 67

symmetrical, incisors, molars

Front 68

------ that result from celiac disease mayresemble ----- or a maternal or early childhood illness

Back 68

Tooth defects, fluorosis

Front 69

Teeth tend to absorb----- and -----

Back 69

discoloration & stain

Front 70

Tooth Staining occurs in------ internally on the enamel, which causes the tooth to appear darker or more yellow overall

Back 70

interprismatic region

Front 71

(bleaching) ofteeth to remove staining that has occurred due to lifestyle choices

Back 71

Whitening

Front 72

The degree to which aperson's teeth will darken can often be related to the amount of repeated exposure they have had to --------

Back 72

chromogenic agents

Front 73

Working chemically, a whitening orbleaching agent is used to carry out an ------- in the enamel & dentin

Back 73

oxidation reaction

Front 74

The agents most commonly used tointrinsically change the color of teeth are ---------- and --------

Back 74

hydrogen peroxide, carbamide peroxide

Front 75

Oxygen radicals from peroxide in whitening agents contact stains in ------ within enamel layer. When this occurs, stains will be ---- andteeth now appear lighter in color

Back 75

interprismatic region, bleached

Front 76

Teeth not only appear whiter but also ----- in increased amounts, which makes teethappear brighter as well

Back 76

reflect light

Front 77

Enamel can endure crushing pressure of around ----- pounds per square inch.

Back 77

100,000

Front 78

Enamel in a healthy state, without trauma or disease, can be removed only by ----- or ------.

Back 78

rotary cutting instruments or rough files.

Front 79

Enamel is ----- and has no ----- in it.

Back 79

avascular, nerve supply

Front 80

Enamel provides a hard surface for ----- and -----; it is able to withstand the masticatory impact of ---- to ----- pounds of pressure per tooth.

Back 80

mastication and speech, 20 to 30

Front 81

Thickness of enamel can range per tooth, from --- to ---- mm for incisors and ----mm for molars.

Back 81

0-2mm, 2.6mm

Front 82

Enamel alone is various shades of -----, but it turns various shaded of yellow-white because of underlying -----.

Back 82

bluish white, dentin

Front 83

What surfaces of the teeth are eroded by acid content of vomit when a patient has bulimia?

Back 83

the lingual surface of maxillary anterior teeth and occlusal surface of maxillary posterior teeth

Front 84

Is it necessary to polish the teeth to remove dental biofilm before topical fluoride application or, before enamel sealant.

Back 84

No

Front 85

Enamel matrix is produced by ameloblast during its ---- phase.

Back 85

secretory

Front 86

The ameloblast are columnar cells that differentiate during the ---- stage in the crown area. Ameloblast are not differentiated in the ---- area; thus, the enamel is usually just confined to the anatomic crown.

Back 86

apposition, root

Front 87

Ameloblast produce approximately ---- of enamel matrix daily during tooth development.

Back 87

4 um

Front 88

Tomes process

First the body of the cell between the processes deposit ----- between ameloblast, which will become the periphery of the enamel rods, forming an outside mold for the enamel between the enamel rods.

Back 88

enamel matrix

Front 89

Tomes process

Secondly, the Tomes process of individual ameloblast will infill the future main body of the -----. Thus there is a one-to-one relationship between the secretory face of Tomes process and each enamel rod produced. However, multiple ameloblast contribute to the enamel between the enamel rods.

Back 89

enamel rod

Front 90

Enamel matrix is an ----- product, because ameloblast are derived from the inner enamel epithelium of the enamel organ which was originally deriveed from the ectoderm of the embryo.

Back 90

ectodermal

Front 91

Enamel does not contain -----. It has two unique classes of protein ----- and ----- as well as ----

Back 91

collagen protien, amelogins, ameloblastin, enamelins

Front 92

Because it only has a small amount of calcium, the initial enamel matrix is therefor only -----, as compared with fully matured and mineralized enamel.

Back 92

partially mineralized

Front 93

Ameloblast are responsible for the partially mineralized state of the enamel matrix, beaus they actively pump ----- into the forming enamel matrix as it is being secreted by each of the the Tomes processes.

Back 93

calcium hydroxypatite p. 150