Unit 11 - Dentin and Pulp

Question 1

Resistance of a material to breaking under pressure

Answer 1

Tensile strength

Question 2

Chemical characteristics of dentin

Answer 2

70% inorganic
20% organic
10% water

Question 3

Is dentin harder than bone?

Answer 3

Yes

Question 4

Is dentin vascular?

Answer 4

No

Question 5

Three types of dentin

Answer 5

Primary
Secondary
Tertiary

Question 6

When does dentinogenesis begin?

Answer 6

In the late bell stage of tooth development

Question 7

Describe dentinogenesis

Answer 7

Odontoblasts orginate from neural crest cells of the papilla. Odontoblasts are introduced by the inner enamel epithelial cells in the crown and hertwig’s epithelial cells on the root.

Question 8

Collagen fibrils in the first layer of the dentin matrix are course in texture and are laid

Answer 8

Perpendicular to the DEJ

Question 9

What are the collagen fibrils in the first layer that are laid perpendicular to the DEJ called?

Answer 9

Von Kroff’s fibers

Question 10

Collagen fibers in the remaining layers are

Answer 10

Finer and run paralell to the DEJ

Question 11

Uncalcified matrix is referred to as

Answer 11

Predentin

Question 12

During matrix production phase, unmineralized dentin remains present adjacent to the

Answer 12

Odontoblasts

Question 13

During dentin’s first phase of maturation, a membrane bound vesicle is deposited in the matrix. This vesicle contains

Answer 13

Several hydroxyappetite crystals

Question 14

Describe the first phase of maturation for dentin development

Answer 14

A membrane bound vesicle is deposited in the maxtrix. This vesicle contains several hydroxyappetite crystals.

The crystals is the vesicle will grow until large enough to rupture the membrane

Many growing crystals will coalesce with one another obsurcing the matrix

Gradually the crystals fuse to each other until the dentin is fully mineralized

Question 15

Describe the second phase of maturation during dentin development

Answer 15

New areas of crystal formation appear and expand but do not fuse completely to each other

The globules of mineralizing dentin remain visible in the predentin/dentin border

Mineralization process is now complete. Fusion during the secondary mineralization phase results in microscopic differences

Question 16

Areas of complete crystaline fusion of dentin are refered to as

Answer 16

Globular dentin

Question 17

Areas of incomplete fusion of globules of dentin are referred to as

Answer 17

Interglobular dentin

Question 18

Dentinal tubules extend through the dentin from DEJ to pulp in an _______ shape

Answer 18

S

Question 19

The tubules provide the space in which the _______________ is housed

Answer 19

Odontoblast process

Question 20

Odontoblastic processes are responsible for

Answer 20

Maintaining and repairing dentin after the caries process and dental restorative procedures

Question 21

The tubules are crowded at the ______ surfaces

Answer 21

Occulsal or incisal

Question 22

What runs off from the tubles to inter-connect tubles?

Answer 22

Lateral extensions

Question 23

What results in the permeability quality of dentin?

Answer 23

Dentinal tubules

Question 24

Type of dentin that appears as a bright halo, hypermineralized, region between the tubules is a less mineralized region.

Answer 24

Peritubular

Question 25

Type of dentin that appears between the tubules and is the majority of dentin. It is less calcified than peritubular.

Answer 25

Intertubular

Question 26

The outermost layer of dentin and the root is mostly made up of this type of dentin

Answer 26

Mantle

Question 27

The term used to describe an area of dentin

Answer 27

Circumpulpal

Question 28

Dentin formed before the apical foramen was complete

Answer 28

Primary

Question 29

Dentin formed after the apical formaen due to everyday stimuli

Answer 29

Secondary

Question 30

Dentin formed in response to trauma

Answer 30

Tertiary

Question 31

Formed during rythmic active and quiet phases which makes a difference appearance of layers. The lines run at right angles to the tubules

Answer 31

Incrimental Lines of Von Ebner

Question 32

This results from an illness or metabolic disturbance and is a band of dentin that is slightly different in composition from the rest of dentin layers.

Answer 32

Contour Lines of Owen

Question 33

These are islands of non-calcified dentin. Located in the surface layer of cementum in root dentin.

Answer 33

Tomes granular layer

Question 34

In aging dentin, the diameter narrows tubule narrows because of

Answer 34

Deposition of peritubular dentin

Question 35

When the tubules are completely calcified it is referred to as

Answer 35

Sclerotic dentin

Question 36

Functions of pulp

Answer 36

Support Sensory Nutritive Protective

Question 37

Pulp anatomy: apical foramen size

Answer 37

0.3 - 0.6 mm diameter

Question 38

What happens to the apical foramen with age?

Answer 38

Reduces in size due to cementum and dentin gradually depositing

Question 39

Extra canals which develop where the Hertwig's Epithelial Root Sheath was interrupted by blood vessels passing through it.

Answer 39

Accessory canals

Question 40

Removal of pulp chamber and pulp horns

Answer 40

Pulpectomy

Question 41

Removal of the pulp horns only

Answer 41

Pulpotomy

Question 42

Removal of the coronal and radicular pulp

Answer 42

Endodontic therapy (RCT)

Question 43

Calcified bodies in pulp that can form with the pulp or with age or if the pulp becomes ill

Answer 43

Pulp stones or denticles

Question 44

What is microscopically seen that the deposits resemble dentin by exhibiting tubules and a process? They are formed with the tooth often in the root canals but can also be in the center of the pulp

Answer 44

True denticles

Question 45

What are the three types of denticles?

Answer 45

True Denticles False Denticles Diffuse/embedded Calcifications

Question 46

What type of denticle is formed with age, usually in the coronal pulp and formed with minerals around debris in the pulpal tissue?

Answer 46

False denticles

Question 47

How are false denticles viewed under microscope?

Answer 47

Irregular concentric layers of a calcified matrix

Question 48

What type of denticle forms due to an ill pulp inducing spontaneous calcifications in a number of locations?

Answer 48

Diffuse/embedded denticles

Question 49

How are diffuse/embedded denticles viewed under a microscope?

Answer 49

Same as false denticles in structure and usually seen in the root