ID 3 Tooth anatomy and tooth supporting structures

Question 1

What are the 3 main dental tissues

2) What surrounds the roots

Answer 1

1) Enamel, Dentine, Pulp

2) Cementum

Question 2

What are the functions of the teeth

Answer 2

Mastication
Appearance
Speech
Maintaining vertical position and jaw guidance

Question 3

Describe the following for Enamel:

1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving

Answer 3

1) White
2) 95%
3) Extremely hard
4) Brittle
5) Nonliving

Question 4

Describe the following for Enamel

6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential

Answer 4

6) Ameloblast
7) none
8) no
9) no
10) no

Question 5

state the following for Enamel:

1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving

Answer 5

1) White
2) 95%
3) Extremely hard
4) Brittle
5) Nonliving

Question 6

state the following for Enamel

6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential

Answer 6

6) Ameloblast
7) none
8) no
9) no
10) no

Question 7

state the following for Dentine:

1) Colour
2) Mineral Content
3) Hardness
4) Resilience
5) Living or nonliving

Answer 7

1) cream
2) 70%
3) hard
4) very resilient (not brittle)
5) living

Question 8

state the following for Dentine

6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential

Answer 8

6) Odontoblast
7) Odontoblast
8) Yes
9) Yes-pain
10) yes

Question 9

state the following for Cementum:

1) Colour
2) Mineral Content
3) describe Hardness
4) Resilience
5) Living or nonliving

Answer 9

1) cream
2) 61%
3) softer than dentine; harder than bone
4) tough
5) living; may die in maturity

Question 10

state the following for Dentine

6) Formative cell
7) nutritive cell
8) Requirements for nourishment
9) Sensitivity
10) Repair Potential

Answer 10

6) cementoblast
7) none or cementocytes
8) no
9) no
10) yes

Question 11

What compound does enamel mainly consist of?

Answer 11

calcium hydroxylapatite

Question 12

What is the crystalline structural unit of enamel?
How many of these can an ameoblast make?
How are they linked together?

Answer 12

enamel prism
1
Many rods come together with complex interconnecting structures along their length, they form a long curve in vertical plane of sections and undulate up and down in the plane of the section

Question 13

What are ameloblasts

Answer 13

cells present only during tooth development that deposit tooth enamel, which is the hard outermost layer of the tooth forming the surface of the crown

Question 14

What is decussation ( when applied to enamel)

Answer 14

The way in which the enamel prisms come together form a long curve in vertical plane of sections and undulate up and down in the plane of the section

Question 15

What is predentine?

Answer 15

a band of newly formed, unmineralised matrix of dentine at the pulpal border of the dentine

Question 16

What is _________ dentine?

1) Primmary
2) secondary
3) tertairy

Answer 16

1) formed before completion of root
2) Formed after after root formation
3) Formed due to damdge

Question 17

what are the 2 types of tertiary dentine, what is the difference between them?

Answer 17

1) 3’ reactionary dentine- formed by original odontoblasts, in reaction to small stimulus/ injury
2) 3’ reparative dentine- formed by newly recruited odontoblasts when repair is required as big injury

Question 18

What is present in the pulp?

Answer 18

1) Fibrous connective tissues (collagen)
2) Blood vessels and nerves
3) some cells
4) sometimes pulps stones

Question 19

Where do Blood vessels and nerves enter the tooth?

Answer 19

apical foramen and accessory canals

Question 20

What cells are present in the pulps?

Answer 20

odontoblasts, fibroblast, undifferentiated cells & defence cells

Question 21

What are the causes of pulp stones?

Answer 21

• injury

- Age-related, older pulp are less vascular (fewer blood vessels) and get mineralised in the form of pulp stones

Question 22

Why is fissure sealant applied to molars and premolars?

Answer 22

To fill in occlusal fissures as as frequent site of carries since it cannot be kept clean with toothbrush bristles

Question 23

What 4 tissues make up the periodontium?

Answer 23

1) Gingiva
2) Periodontal ligament
3) Alveolar bone
4) Cementum

Question 24

What is the function of the periodontium?

Answer 24

1) attach teeth to jaws

2) Support teeth during chewing- loads create lateral & horizontal movements

Question 25

What is attached gingiva attached to? what polymer does it contain?

Answer 25

attached to underlying bone, keratinized (has keratin- makes things tough)

Question 26

What is the free gingiva?
Where is it?
What colour is it?
What polymer is present in it?

Answer 26

• not free but movable
• Extends from gingival margin to bottom of gingival sulcus
• light pink
• both keratinized and non-keratinized

Question 27

What is the function of the junctional epithelium?
Where is it in healthy teeth?
What is a property of the junctional epithelium?

Answer 27

• attaches gingiva to enamel
• apically (bottom of) at cemento-enamel junction
• permeable or “leaky” - less tight junctions between cells- allow crevicular fluid to flow into sulcus (crevice) with immune defence cells

Question 28

What is the function of keratin?

Answer 28

keratin protects the tissue from damage due to abrasive forces during mastication

Question 29

What is the function of keratin?

Answer 29

keratin protects the tissue from damage due to abrasive forces during mastication

Question 30

What is the function of the periodontal ligament?

Answer 30

connect Cementum and alveolar bone

Question 31

What cells does the periodontal ligament contain and for what function:

Answer 31

1) Cementoblast- form cementum
2) fibroblasts- form fibres
3) Osteoblasts - form bon

Question 32

What is the periodontal ligament?

Why is it important it has this strucuture?

Answer 32

-Dense, fibrous connective tissue where the collagen fibres are orientated in groups (bundles) for maximal strength, This is important as it means fibre bundles can resist intrusion (moving of tooth into alveolus) of tooth during mastication.

Question 33

What are sharpey’s fibres?

Answer 33

principle fibres embedded in bone and cementum that are a part of periodontal ligaments

Question 34

What are the properties of Periodontal ligament or membrane?

Answer 34

• stong: due to orientation of fibres in bundles
• high rate of cell turnover
• heals quickly: due to rich vascular supply
• sensory & pain response: rich innervation

Question 35

What are the properties of Periodontal ligament or membrane?

Answer 35

• stong: due to orientation of fibres in bundles
• high rate of cell turnover
• heals quickly: due to rich vascular supply
• sensory & pain response: rich innervation

Question 36

What are the 2 tooth supporting structures (so are part of periodontium) that are mineralised connective tissue?
Where are they in relation to the periodontal ligaments?

Answer 36

1. Cementum
2. Alveolar Bone
   attached either side of it

Question 37

Cementum

1) Where is the acellular cementum?
2) Where is the cellular cementum?
3) How fast does it grow?

Answer 37

1) covering roots, at the top as Aces everything
2) around apex of tooth (got a C so is at bottom of class)
3) Grows slowly and accumulates throughout life

Question 38

What is the alveolar bone? what does it do?

Answer 38

Its part of maxilla & mandible that supports roots of teeth

Question 39

whats the alveolar bone called on a radiograph?

Answer 39

lamina dura

Question 40

What happens to alveolar bone if it receives no stimulus from functional teeth?

Answer 40

resorbed by osteoclasts if no stimulus from functional teeth

Question 41

How big is the pocket in moderate periodontal disease?

Answer 41

4-5.5mm

Question 42

How big is the pocket in severe periodontal disease?

Answer 42

+6mm