1. Anatomy

Question 1

What is the difference between parakeratinized and orthokeratinized nuclei

Answer 1

Parakeratinized has nuclei

Orthokeratinized does not

Question 2

Name the clear cells

Answer 2

1. Merkel - Sensory
2. Langherhan - Defense cells & present antibodies
3. Melanocytes - Produce melanin

Question 3

What is the normal radiographic width of PDL space

Answer 3

0.01 - 0.25 mm

Question 4

What is the turnover of Junctional Epithelium

Answer 4

1 - 6 days.

Question 5

What are the 2 layers of the basement membrane

Answer 5

1. Papillary

2. Reticular

Question 6

What is the blood supply to the PDL

Answer 6

Superior and Inferior Alveolar Arteries

Question 7

What is the difference between woven bone and lamellar bone

Answer 7

Woven Bone: Immature bone with osteoblasts and calcified collagen fibers

Lamellar: More mature bone

Question 8

Where is Lamellar bone found

Answer 8

Cortical Bone

Question 9

Where is bundle bone found, what does it belong to?

Answer 9

Around the tooth, it belongs to the tooth
It is 1 mm thick
It resorbs following extraction of teeth no matter what

Question 10

What type of collagen is present in bone

Answer 10

Type I

Question 11

What are the stages of tooth development

Answer 11

1. Bud
2. Cap
3. Bell

Question 12

What are ameloblasts derived from

Answer 12

Enamel Organ / Dental Organ

Question 13

What is formed from the dental papilla

Answer 13

1. Pulp

2. Dentine

Question 14

What is derived from the dental follicle

Answer 14

1. PDL
2. Bone
3. Cementum

Question 15

Discuss how root structure develops starting at the bell stage

Answer 15

IEE + REE combine to form cervical loop
Cervical loop divides into Hertwigs Epithelial Root Sheath
Papilla contacts HERS - forms osteoblast
Follicle brakes down, causing cementoblast to differentiate exposing dentine
Further away fibroblast between collagen form PDL

Question 16

How does active eruption occur

Answer 16

Oblique orientated fibers pull down the tooth

Question 17

How does attachment of JE to tooth surface develop

Answer 17

Primarily from OEE and REE

Question 18

Discuss cementum

Answer 18

Acellular / Cellular
Made of type I and III collagen
Primary acelluar cementum laid down first, has intrinsic fibers
As this thickens it meets the PDL and traps fibers called extrinsic fibers

Question 19

What are Sharpeys fibers

Answer 19

Fibers trapped in bone

Question 20

What is secondary cementum

Answer 20

Cellular cementum in the apical 1/3

Question 21

What is Afibrillar cementum

Answer 21

Thin layer at the enamel junction

Question 22

What forms intrinsic fibers

Answer 22

Cementum

Question 23

What forms extrinsic fibers

Answer 23

Bone

Question 24

How does enamel meet cementum

Answer 24

1. Gap - 5%
2. Butt - 30%
3. Overlay - 65%

Question 25

What are the main PDL fiber groups

Answer 25

``` Apical Oblique Radicular Trans Septal Alveolar Horizontal ``` AORTA H

Question 26

What are the gingival fiber groups

Answer 26

1. Dentogingival 2. Dentoperiosteal 3. Alveologingival 4. Circumferential 5. Semi Circular 6. Transgingival 7. Intergingival 8. Trans Septal

Question 27

What type of collagen in PDL

Answer 27

Type 1 - 80% | Type 3 - 20%

Question 28

What other fibers in PDL apart from collagen

Answer 28

Eutectin | Oxytalin

Question 29

What is between the PDL fibers

Answer 29

1. Ground Substance 2. Fibronectin 3. Glycosaminoglycans 4. Water

Question 30

Where are osteoclasts derived from

Answer 30

Monocytes / Macrophages in the presence in RANKL

Question 31

How does the JE attach to the tooth

Answer 31

Hemi Desmosomes

Question 32

What are the tissues of the periodontium

Answer 32

Gingiva CT attachment PDL Alveolar Bone

Question 33

What are the 3 zones of epithelium in the periodontium

Answer 33

1. Oral Epithelium 2. Crevicular / Sulcular Epithelium 3. Junctional Epithelium

Question 34

What are the layers of the epithelium from inferior to superior

Answer 34

1. Basale 2. Spinosum 3. Granulosum 4. Corneum

Question 35

Discuss the stratum basale

Answer 35

Cuboidal Cells Lots of mitochondria LMW keratin High mitotic activity

Question 36

Discuss the stratum spinosum

Answer 36

Polyhedral in shape Less cell division Higher molecular weight proteins present

Question 37

Discuss the stratum granulosum

Answer 37

Cells flatten out Lots of keratohyaline granules Not present in NON KERATINIZED EPITHELIUM

Question 38

Discuss the stratum corneum

Answer 38

Keratohyaline granules disappear

Question 39

Describe the oral epithelium

Answer 39

All 4 epithelium stem cells present Most parakeratinized Prominent Rete pegs Slower turnover - 6 to 12 days

Question 40

Describe the sulcular epithelium

Answer 40

Basal, Spinous and Granular layers present Thinner Non Keratinized From gingival crest to junctional epithelium Few Rete Pegs

Question 41

Discuss the Junctional Epithelium

Answer 41

Non keratinized Thin ( 3 -4 Cells thick) Short turnover

Question 42

What is the lamina densa

Answer 42

The attachment adjacent to enamel

Question 43

What is the lamina lucida

Answer 43

Where hemidesomosomes of the epithelium cell BM attach

Question 44

At what level do JE attach to the tooth

Answer 44

At or slightly coronal to the CEJ

Question 45

What is the blood supply to the cancellous bone

Answer 45

- PDL - Periosteum - Bone itself

Question 46

What is the lamina dura

Answer 46

A radiographic term for the radio dense line along the socket wall

Question 47

How does passive eruption occur

Answer 47

Migration of the gingiva due to the splitting of tje secondary epithelial attachment Splitting stops at CEJ

Question 48

What does the secondary epithelium attachment become

Answer 48

Junctional Epithelium

Question 49

How are cells bound to tthe basement membrane

Answer 49

Type 4 collagen - basal lamina | Type 7 Collagen - papillary layer

Question 50

Why is the JE vulnerable to bacterial insults

Answer 50

Wide intracellular spaces | So bacteria can penetrate