Tooth Tissues

Question 1

What is the hardest tissue in the body?

Answer 1

Enamel

Question 2

What is enamel made from?

Answer 2

Ameloblasts produce enamel proteins.

Question 3

What characteristic of enamel increases with mineralisation?

Answer 3

Transparency.

Question 4

Where does enamel develop from in the early stages?

Answer 4

Intrauterine glands.

Question 5

Enamel is formed as a..?

Answer 5

Matrix.

Question 6

What is Tomes process?

Answer 6

Establishes the crystals in which enamel rods are formed from.

Question 7

What are enamel rods composed of?

Answer 7

Crystallites.

Question 8

Enamel is formed outwards from what junction?

Answer 8

The amelo-dentinal junction.

Question 9

Describe the variations in enamel thickness.

Answer 9

Thicker and more mineralised at the incised edge/occlusal surface, decreases as you approach the cervical margin.

Question 10

How are enamel rods deposited?

Answer 10

Deposited at right angles to the ameloblast membrane.

Question 11

What do the rods contain?

Answer 11

Hydroxyapatite crystals.

Question 12

What makes the Hydroxyapatite crystals more stable?

Answer 12

Replacing the OH with Fluoride.

Question 13

Name the 2 features of the crystallite structure.

Answer 13

Head and tail.

Question 14

Hydroxyapatite makes up what percentage of the enamel weight?

Answer 14

95%

Question 15

Water makes up what percentage of the enamel weight?

Answer 15

4%

Question 16

The organic matrix makes up what percentage of the enamel weight?

Answer 16

1%

Question 17

What happens to a tooth if the water is removed?

Answer 17

Becomes extremely brittle.

Question 18

Dentine is the supporting tissue beneath..

Answer 18

Enamel.

Question 19

Why is dentine permeable?

Answer 19

It contains dentinal tubules.

Question 20

What colour is dentine?

Answer 20

Yellow(ish)

Question 21

Where is dentine thickest?

Answer 21

In the areas that receive the greatest force.

Question 22

Hydroxyapatite makes up what percentage of the dentine weight?

Answer 22

70%

Question 23

Water makes up what percentage of the dentine weight?

Answer 23

10%

Question 24

Organic matrix makes up what percentage of the dentine weight?

Answer 24

20%

Question 25

When is primary dentine present?

Answer 25

When the tooth is forming.

Question 26

When is secondary dentine present?

Answer 26

Once the tooth has been formed.

Question 27

When is tertiary dentine present?

Answer 27

In repair.

Question 28

What direction does dentine grow in?

Answer 28

Inwards.

Question 29

What shape is primary dentine?

Answer 29

'S' shape

Question 30

What shape is secondary dentine?

Answer 30

Wavy shape.

Question 31

Describe the relationship between caries and the dentinal tubules.

Answer 31

Caries follow the shape of the tubules inside the tooth and can affect the deeper layers.

Question 32

What processes from the pulp extend into dentine?

Answer 32

Odontoblast projections.

Question 33

Where is the dental pulp and dentine formed?

Answer 33

The dental papilla.

Question 34

The pulp is..

Answer 34

Vascular and innervated with unmyelinated nerve ending)

Question 35

What does the pulp mainly consists of? What is its function?

Answer 35

Odontoblasts. Produce dentine.

Question 36

Describe blood vessels in relation to dentine.

Answer 36

Blood vessels are close to dentine but never embedded in the dentine.

Question 37

What is the purpose of cementum?

Answer 37

Covers root dentine

Question 38

What does cementum provide attachment for?

Answer 38

The periodontal fibres

Question 39

Name the 2 types of cementum.

Answer 39

Cellular and Acellular.

Question 40

What is the first cementum to be formed?

Answer 40

Acellular cementum

Question 41

What cementum contains Sharpey fibres?

Answer 41

Acellular cementum

Question 42

What is the function of the sharpey fibres?

Answer 42

Attach the tooth to the alveolar bone.

Question 43

What cells does the cellular cementum contain?

Answer 43

Cementocytes.

Question 44

Where is cellular cementum found?

Answer 44

At the apical parts of the root and furcations.

Question 45

Name the 3 ways the cementum sits in relation to dentine.

Answer 45

Touch, overlap or expose the dentine.

Question 46

What type of fibre cementum are sharpey fibres?

Answer 46

Acellular extrinsic fibres.

Question 47

What does cellular intrinsic fibre cementum lack?

Answer 47

Sharpey's fibres

Question 48

What does cellular intrinsic fibre cementum not have a role in?

Answer 48

Tooth attachment

Question 49

What is the rule in relation to fibres and cellular tissue.

Answer 49

The more cellular the tissue the less fibres are present.

Question 50

What is the function of the periodontal ligament?

Answer 50

Transfers biting forces to the bone.

Question 51

What cells are present in the periodontal ligament?

Answer 51

Fibroblasts, cementoblasts, osteoclasts and debris of malassez.

Question 52

What sensory cells are present in the periodontal ligament?

Answer 52

Nociceptors: Initiates reflex to protect teeth. Mechanoreceptors: Detect the pressure on teeth.

Question 53

What are true periodontal fibres?

Answer 53

Connects tooth to the bone

Question 54

What is the gingival ligament?

Answer 54

Connective tissue that provides support to the fibres.

Question 55

Name the principal fibre groups of the periodontal ligament.

Answer 55

Alveolar crest: (Similar to horizontal) Horizontal: Limits lateral movement and rotation Oblique: Resist vertical and intrusive movement. Apical: Provides cushioning. Inter-radicular: Found between the roots of multi-rooted teeth.

Question 56

What is the purpose of trans-septal fibres? Why are these fibres unique?

Answer 56

Keep teeth aligned. Do not have and osseous attachment.