Dental, Pulp & Enamel

Front 1

Hard protective layer of tooth

Back 1

Enamel

Front 2

Interlocking rods that resist masticatory forces

Back 2

Enamel rods

Front 3

Deposited perpherally from DEJ in key-hole shape by ameloblast & grows 4 micrometers a day

Back 3

Enamel rods

Front 4

Dark lines showing age of enamel rods

Back 4

Straie of Retzius

Front 5

Rods are clinically evident as

Back 5

Perikymata

Front 6

enamel has _______, dentin has _________

Back 6

- rods
- tubules

Front 7

The enamel rod configuration viewed in incidental light appears as light and dark bands of rod groups termed

Back 7

Hunter-Schreger bands

Front 8

hypocalcified zones caused by bending of adjacent groups of rods

Back 8

Tufts

Front 9

The termination of the dentinal tubules in enemal are

Back 9

Spindles

Front 10

When rods bend in an exaggerated, twisted manner at the cusp tips, they are called

Back 10

gnarled enamel

Front 11

Enamel contains

Back 11

96% hydroxyapatite
4% water & organic matter

Front 12

The organic component of enamel is the protein

Back 12

enamelin

Front 13

enamelin is similar to the protein _______, which is found in the skin

Back 13

keratin

Front 14

Enamel is ___________ in color and dentin is ___________

Back 14

- grayish-white
- yellowish

Front 15

Enamel is thickest on the _____

Back 15

tip (occlusal & incisal surface)

Front 16

Enamel is composed of rods that extend from _______ to enamel outer surface

Back 16

DEJ

Front 17

_____ ameloblast forms enamel rod

Back 17

4 : 1 forms head
part of 2 forms neck
1 forms tail

Front 18

enamel rods are ________ shaped

Back 18

key-hole

Front 19

Enamel rods curve slightly to

Back 19

cusp tip

Front 20

______ are the result of the rhythmic recurrent deposition of the enamel

Back 20

Incremental lines

Front 21

"growth lines"

Back 21

striae of Retzius
(lines of Retzius)

Front 22

Environment and nutrition changes that occur abruptly at time of birth cause a noticeable line of Retzius known as

Back 22

neonatal line

Front 23

Enamel defect filled with organic material located at a right angle to DEJ is

Back 23

Enamel Tuft

Front 24

Ridges on enamel are a result of termination of ____________ on enamel surface

Back 24

Straie of Retzius

Front 25

Perikymata is also known as

Back 25

imbrication lines

Front 26

protects Dentin from trauma

Back 26

Enamel

Front 27

Imbrication lines are more prominent on the ________ surface

Back 27

facial

Front 28

Enamel is impermeable but can be permeable if:

Back 28

- faulty restorations
- tooth decomposition by dental caries
- pathways such as lamellae, cracks, tufts, spindles

Front 29

The minute spaces between or around enamel rods and through crystal spaces within rods are called

Back 29

microlamellae

Front 30

etching is done with ______ acids

Back 30

- dilute
such as 35-40% phosphoric acid

Front 31

True or False:
Dentin is a living tissue.

Back 31

True

Front 32

Root dentin is covered by

Back 32

cementum

Front 33

Crown Dentin is covered by

Back 33

enamel

Front 34

what are the different kinds of dentin

Back 34

- Primary
- Secondary
- Tertiary (AKA reparative)

Front 35

Dentin that is laid down first

Back 35

Primary Dentin

Front 36

Also known as reparative dentin

Back 36

Tertiary dentin

Front 37

this dentin is the major component of crown & root

Back 37

Primary Dentin

Front 38

Primary dentin is composed of

Back 38

- Mantle Dentin
- Circumpulpal dentin

Front 39

_______ dentin is closest to pulp

Back 39

Circumpulpal

Front 40

___________ dentin underlies _________ dentin

Back 40

- circumpulpal
- Mantle

Front 41

Primary Dentins tubules are _____ shaped to withstand force

Back 41

"S"

Front 42

Mantle dentin has ___________ with enamel at DEJ

Back 42

interdigitation

Front 43

Dentin that is nearly free of developmental defects

Back 43

Mantle Dentin

Front 44

Mantle dentin is seperated from circumpulpal dentin by _________ dentin

Back 44

globular

Front 45

A zone of disturbed dentin formation

Back 45

globular dentin

Front 46

globular dentin is noted by the hypomineralized spaces between the globules termed

Back 46

interglobular spaces

Front 47

_________ are not true spaces but are less mineralized areas between the calcified globules.

Back 47

interglobular spaces

Front 48

Interglobular dentin is especially noticeable with a

Back 48

Vitamin D defciency, which affects mineralization of teeth and bones

Front 49

forms internally and occurs as a reaction to a lot of pressure (chewing & other habits)

Back 49

Secondary dentin

Front 50

Secondary dentin is deposited more ________ than primary dentin

Back 50

slowly

Front 51

results from pulpal stimulation and forms only at the site of odontoblastic activation

Back 51

Tertiary or reparative dentin

Front 52

Deposited to to protect pulp near caries or trauma

Back 52

Tertiary Dentin (reparative dentin)(response dentin)

Front 53

Reparative dentin at times resembles bone more than dentin and is termed

Back 53

osteodentin

Front 54

newly formed dentin before calcification and maturation at pulpal border

Back 54

Predentin

Front 55

Predentin is composed of ________ fibers that calcify in 24 hours

Back 55

collagen

Front 56

Predentin is evidence that Dentin forms in two stages:

Back 56

- first the organic matrix is deposited
- second an inorganic mineral substance is added

Front 57

Incremental lines are due to

Back 57

Appositional growth

Front 58

The odontoblasts may die because of trauma or old age, and ________ then develop in dentin

Back 58

dead tracks

Front 59

as minerals fills the tubules and later calcify, _________ is formed, closing the end of the tubule

Back 59

Sclerotic dentin

Front 60

Dentin appears _________ after endontic therapy (RCT - root canal therapy)

Back 60

darker

Front 61

Dentin is made up of

Back 61

- 70% hydroxyapatite crystals
- 20% organic collagen fibers, other proteins
- 10% water

Front 62

Dentin is _______ than enamel. slightly _______ than bone or cementum.

Back 62

- softer
- harder

Front 63

Dentin is more __________ than enamel, and more ___________ than pulp.

Back 63

- radiolucent
- radioopaque

Front 64

Dentin is _______ likely to fracture

Back 64

less

Front 65

Primary dentinal is the ______ tube, and the secondary dentinal ___________ the primary tube

Back 65

- main
- branches off

Front 66

Intratubular dentin are _________ tubes and peritubular dentin _______ the tubes

Back 66

- in between
- circles

Front 67

Sclerotic dentin is also called

Back 67

transparent dentin

Front 68

Imbrication lines are also called

Back 68

Lines of Von Ebner

Front 69

Neonatal line reflects the

Back 69

abrupt nutritional change that occurs at birth

Front 70

Juntion between dentin & enamel

Back 70

DEJ

Front 71

Loss of odontoblastic process reveals ___________ in dentin

Back 71

dead tracks

Front 72

the spindles that are extensions of the odontoblastic process extend a short distance into the

Back 72

enamel

Front 73

Once the spindles of the odontoblastic process extend to the enamel, the odontoblastic process then forms an _____ which extends to the ______

Back 73

- S curve
- pulp

Front 74

cytoplasmic extensions of cell body that are postitioned at pulp/dentin border

Back 74

odontoblastic process

Front 75

Odontoblastic process is largest in diameter near ______ and taper toward _____

Back 75

- pulp
- DEJ

Front 76

________ are found near odontoblastic cell body

Back 76

nerve endings

Front 77

______ surface of dentin is about 5 times in surface area than ________ surface

Back 77

- outer
- inner

Front 78

Tubules are farthest apart at

Back 78

DEJ

Front 79

Tubules are closest together at

Back 79

pulp

Front 80

Peritubular dentin is ________ calcified than intertubular dentin

Back 80

more

Front 81

fine particles of cut dentinal debris that are produced by cavity preperation

Back 81

smear layer

Front 82

Dentin is laid down ___________ life

Back 82

throughout

Front 83

Patholgic effects cause

Back 83

- Odontoblastic degeneration
- dead tract formation
- calcification of tubules leading to sclerosis
- tertiary formation

Front 84

soft CT located in central portion of each tooth

Back 84

dental pulp

Front 85

two parts of pulp

Back 85

- coronal portion (crown)
- radicular portion (root)

Front 86

pulp space contains

Back 86

blood vessels, nerves, & nerve endings enclosed in dentin

Front 87

Pulp enters periodontium through

Back 87

apical foramen

Front 88

within coronal or radicular portion of pulp, there are two parts: the

Back 88

- central zone
- peripheral zone

Front 89

the central zone is

Back 89

the center

Front 90

the peripheral zone is

Back 90

around the central zone

Front 91

central zone contains

Back 91

-arteries, veins, nerve trunks from apical foramen
- fibroblasts (most common) & odontoblasts (2nd most common)

Front 92

most popular theory of dental pain perception

Back 92

hydrodynamic theory

Front 93

pulp functions

Back 93

- initiative
- formative
- protective
- nutritive
- reparative

Front 94

stones can be ______, _______, or ________ in pulp tissue

Back 94

- attached
- embedded
- free

Front 95

humans have ____ dental pulps: ____ primary dentition & _____ permanent dentition

Back 95

- 52
- 20
- 32

Front 96

all dental pulps have similar characteristics:

Back 96

- soft, gelatinous
- surrounded by dentin

Front 97

coronal pulp is ______ than radicular pulp

Back 97

larger

Front 98

_______ in age = ________ coronal pulp size

Back 98

- older
- smaller

Front 99

______ in age = ________ radicular pulp size

Back 99

- older
- smaller

Front 100

smaller apical canals are referred to as

Back 100

accessory canals

Front 101

_____ the pulp is composed of large veins, arteries, nerve trunks surrounded by fibroblasts & collagen fibers

Back 101

centrally

Front 102

________ along the dentin in both coronal and radicular pulp are formative cells of dentin, odontoblasts.

Back 102

Peripherally

Front 103

includes the odontoblasts, the cell-free zone, & the cell rich zone

Back 103

odontogenic zone

Front 104

the cell free zone is also known as

Back 104

zone of Weil or Weil's basal layer

Front 105

adjacent to the cell free zone is a zone of high cell density called the

Back 105

cell rich zone

Front 106

pulpal to the cell rich zone is the

Back 106

parietal layer of nerves

Front 107

_______ line the perimeter of the pulp

Back 107

odontoblasts

Front 108

most numerous cells in pulp because they are located throughout pulp

Back 108

fibroblasts

Front 109

Odontoblast are small and ________ shaped when they first differentiate but soon become _________ shaped.

Back 109

- oval
- columnar

Front 110

Once the odontoblast become column shaped, they develop ______ or extensions around which dentin form

Back 110

processes

Front 111

The active cell has a large ______ in its basal part and a _________ in its apical part

Back 111

- nucleus
- golgi apparatus

Front 112

There is abundant __________ and numerous ________ scattered through the cell body

Back 112

- rough Endoplasmic Reticulum (RER)
- mitochondria

Front 113

Three types of junctional complexes ar found between adjacent ondontoblasts:

Back 113

- tight (zonula occludens)
- gap
- intermediate

Front 114

openings bewtween odontoblasts for communication of cell electrical impulses and passage of small molecules

Back 114

Gap juntions

Front 115

with age, ___________ appear smaller and shaped like a spindle with few organelles

Back 115

Fibroblasts

Front 116

In young pulp, fibroblasts produce _________ fibers and ______________

Back 116

- collagen
- ground substance

Front 117

collagen type I is from _______ and collagen type III is from __________

Back 117

- odontoblasts (because found in dentin as well)
- fibroblasts

Front 118

nerve cells in the pulp include

Back 118

Schwann's cells

Front 119

Schwann cells form the

Back 119

myelin sheath of nerves and are associated with all pulp nerves

Front 120

endothelial cells line the

Back 120

- capillaries, veins and arteries of the pulp

Front 121

Accompanying most vessels are ______ and numerous _________ cells found in normal pulp

Back 121

- pericytes
- undifferentiated

Front 122

________ are also found in pulp free spaces and probably function in an immune system of pulp

Back 122

Lymphocytes

Front 123

Erythrocytes, lymphocytes, leukocytes, eosinphils and basophils are als found in the pulp ____________

Back 123

blood vessels

Front 124

Collagen fibers exist in the __________ matrix which surrounds the cells.

Back 124

extracellular

Front 125

the pulp organ is highly vascularized, with vessels arising from the ___________ to the _________ and __________ alveolar arteries

Back 125

- carotid arteries
- superior
- inferior

Front 126

The vessel lining consist of Three layers:

Back 126

- Intima (inner)
- Media (middle)
- Adventitia (outer)

Front 127

the initma layer consists of

Back 127

oval or squamous shaped enothelial cells surrounded by a closely associated fibrillar basal lamina

Front 128

the middle layer of the vessel linning consists of

Back 128

muscle cells from one to three cell layers thick

Front 129

the outer layer or adventitia of the vessel linning consitst of

Back 129

a sparse layer of collagen fibers forming a loose network around the larger arteries

Front 130

Blood pressure and blood flow is _________ in dental pulp compared to the rest of the body

Back 130

high

Front 131

Several large nerves enter the ______ end of each molar and premolar, and single nerves enter the anterior teeth

Back 131

apical

Front 132

Nonmyelinated axons also enter with ____________ axons, but they are smaller

Back 132

myelinated

Front 133

the large nerve trunks are invested with

Back 133

Schwann's cells

Front 134

This network, comprising both myelinated and nonmyelinated axons, is known as the

Back 134

parietal layer of nerves or nerve Plexus of Raschkow

Front 135

parietal layer of nerves is also known as

Back 135

Plexus of Raschkow

Front 136

Most pulpal nerve endings are in the _____________ region of the pulp horn

Back 136

odontogenic

Front 137

other nerve endings found in the predentinal tubules, usually in the region of pulp horns or

Back 137

roof of the coronal area

Front 138

the nerve endings are presumed to function in

Back 138

pain reception

Front 139

pulp is highly sensitive to

Back 139

- temperature changes
- electrical and chemical stimuli
- pressure as applied to the inner enamel, dentin or pulp

Front 140

Theories of pain perception are

Back 140

- Direct innervation Theory
- Transduction Theory
- Hydrodynamic Theory

Front 141

Direct Innervation theory is the _______ accepted theory

Back 141

least

Front 142

Direct Innervation theory is based on

Back 142

the belief that the nerves extend to the DEJ.

Front 143

The transduction theory is based on the belief

Back 143

that the odontoblastic process is the receptor and that it conducts the pain to nerve endings in the peripheral pulp and in the dentinal tubules

Front 144

The hydrodynamic theory was developed to explain the

Back 144

transmission of pain throught the thickness of dentin

Front 145

The hydrodynamic theory is based on the premise

Back 145

that when dentin is stimulated, fluid and the odontoblastic process move within the tubules, making contact with the nerve endings in the inner dentin and adjacent pulp. When these nerve endings are contacted, they deform and act as mechanoreceptors to produce an impulse.

Front 146

Inductive function of pulp

Back 146

in early development the pulp interacts with the oral epithelium and initiates tooth formation

Front 147

Formative function of pulp

Back 147

odontoblasts of the pulp form the dentin that surrounds and protects pulp

Front 148

Protective funtion of pulp

Back 148

responds to stimuli, such as heat, cold, pressure, and ooperative cutting procedures. the formation of sclerotic dentin

Front 149

nutritive function of pulp

Back 149

it carries oxygen and nutrition to the developing and functioning tooth

Front 150

reparative function of pulp

Back 150

response to operative cutting or dental caries by the formation of reparative dentin

Front 151

regressive changes in the pulp and surrounding dentin are related to

Back 151

environmental stimuli and aging

Front 152

fibrous changes in the pulp is believed to be caused more by

Back 152

injury than aging

Front 153

pulp stone are also known as

Back 153

denticles

Front 154

pulp stones (denticles) are

Back 154

round to oval calcified masses appearing in either the canal or coronal portions of the pulp organ

Front 155

pulp stones appear in teeth that have

Back 155

suffered injury such as microtrauma as well as in otherwise normal pulps

Front 156

true denticles have

Back 156

dental tubles like dentin

Front 157

false denticles are

Back 157

concentric layers of calcified tissue

Front 158

most denticles are

Back 158

false stones that are free in the pulp

Front 159

free denticles are

Back 159

floating

Front 160

attached denticles are

Back 160

touching dentin

Front 161

embedded denticles are

Back 161

half in dentin and half in pulp space

Front 162

majority of primary dentin is

Back 162

circumpulpal dentin