Dental Pulp

Question 1

The pulp is often referred to as the dentine-pulp complex because the odontoblast processes extend at least —- into the dentinal tubules. Therefore drilling dentine can potentially —- the pulp.

Answer 1

1/3

damage

Question 2

What does the dental pulp contain?

Answer 2

Cells 
Fibres 
Ground substance 
Blood vessels 
Nerves

Question 3

What are the cells of the dental pulp?

Answer 3

Odontoblasts
Stem cells
Fibroblasts
Schwann cells
Defence cells (antigen presenting cells, macrophages, fibroblasts)

Question 4

What are the four functions of the dental pulp?

Answer 4

1. Forms the dentine
2. Eruption of the tooth/root formation
3. Dentine repair
4. Defence against infection and systemic dissemination

Question 5

Hard connective tissue of —–origin, formed by odontoblast cells of dental —-.
Dentine provide the bulk and form of tooth
Dentine forms —- enamel: it determines the —- of the crown, including cusps and ridges and the number and size of the roots.
Dentine is covered by enamel on the anatomic crown and —- on the anatomic root.
Internally, dentine forms the walls of the pulp of the pulp cavity (pulp chamber and pulp canal).
As a living tissue, dentine contains within its —- the process of specialised cells, the odontoblasts.

Answer 5

Mesodermal

papilla

before

shape

cementum

tubules

Question 6

What are the physical properties of dentine?

light and colour

Answer 6

• Varies from light yellowish in deciduous teeth to pale yellow in permanent dentition
• Becoming darker with age
• Because light can readily pass through thin, highly mineralised enamel and be reflected by the underlying dentine, the crown of the tooth has a yellowish appearance
• Thicker enamel does nit permit light to pass through as readily, and in such teeth the crown appears whiter
• Teeth with pulp disease or without a dental pulp show discolouration of the dentine, which causes a darkening of the clinical crown

Question 7

Explain the hardness of dentine:

Answer 7

• Less hard than enamel
• The hardness of dentine averages 1/5 of enamel and its hardness near the EDJ is about three times greater than near the pulp
• Dentine becomes harder with age, primarily due to increase its mineral content
• The lower content of mineral salts in dentine renders it more radiolucent than enamel
• Physically, dentine has an elastic quality, which is important for the proper functioning of the tooth because it provides flexibility and prevents fracture of the overlying more brittle non-resistant enamel.

Question 8

What is the chemical composition of dentine?

What does each part contain?

Answer 8

70% organic, 20% organic, 10% water.

Hydroxyapatite and the organic phase is type 1 collagen with rational inclusions of glycoproteins, proteoglycans and phosphoproteins.

It contains a small amount of phosphates, carbonates and sulphates, insoluble protein and lipids.

Question 9

What content increases with age?

Answer 9

Mineral content.

The inorganic phase makes dentine slightly harder than bone and softer than enamel.

Question 10

How can organic and inorganic substances be separated?

What happens in the process of decalcification?

Answer 10

• decalcification
• incineration

Organic consistents can be retained and maintain the shape the dentine.

Question 11

Why is dentine highly permeable?

Answer 11

Presence of dentinal tubules.

Question 12

Is intratubular or intertubular more mineralised?

Answer 12

Intratubular

Question 13

Structure of dentine:
Odontoblasts, project their —- processes inside the dentinal tubules, up to 1/3 of dentinal thickness.
Dentine tubules are found throughout —-.
Tubules from pulp towards the periphery and join enamel at —-.
Tubules join the cementum at the dentino-cementum junction at —-level.
The dentinal matrix of —- fibres is arranged in a random network.
As dentine —-, the hydroxyapatite crystals mask the individual collagen fibres.

Answer 13

Cytoplasmic

Dentine

EDJ

Root

Collagen

Calcifies

Question 14

What are the two types of tubule?

Where is the S shaped curvature least pronunced?

Answer 14

Straight and S tubules

In the cervical third of the root and between the incised edges&cusps.

Question 15

Where do tubules have the largest diameter?

Where are there more tubules? Crown or root?

Answer 15

Near the pulp

Crown

Question 16

What are canaliculi?

What are enamel spindles?

Answer 16

Lateral branches off tubules in dentine.

Tubules which extend through the EDJ to the enamel.

Question 17

What is intratubular dentine?

Answer 17

The dentine that immediately surrounds the dentinal tubules.

This dentin forms the walls of the tubules in all but the dentin near the pulp.

It is more highly mineralised (about 9%) than intertubular dentine.

Question 18

What causes the size of tubular lumen?

Which type of dentine forms first?

Answer 18

Continuous deposition of peritubular dentine.

Intertubular forms before intratubular.

Question 19

Give details on intertubular dentine

Answer 19

• Main body of dentine is compose of intertubular dentine
• It is located between the dental tubules more specifically, between the ones of intertubular dentine
• About one half of its volume is organic matrix, specifically collagen fibres which are randomly orientated around the dentinal tubules
• Hydroxyapatite crystals, which average 0.1um in length, are formed along the fibres with their long axis orientated parallel to collagen fibres

Question 20

When does dentine become sensitive?

Answer 20

covering of either enamel or cementum is lost due to attrition, abrasion. erosion, caries, fracture, gingival recession

Question 21

Sensitivity in dentine:
What happens with moderate stimuli?
What happens with severe stimuli?

Answer 21

• Pulp responds defensively forming tertiary dentine and sclerotic dentine
• It may damage the pulp (reversible or irreversible). Irreverisible leads to necrosis of pulp and periapical lesions.

Question 22

Give the details on predentine

Answer 22

First formed dentine, not mineralised. Located adjacent to the pulp tissue and 2-6um wide depending on the activity of the odontoblast.
As the collagen fibres undergo mineralisation at the predentine-detnine from the predetnine then becomes dentine and a new layer or predentine forms circus pulpally.
It is the inner most portion of dentine.

Question 23

What type of dividing cells are odontoblasts?

What is their shape in the crown and root?

Answer 23

Post-mitotic cells (cannot divide).

Tall and columnar in crown and cuboidal in root.

Question 24

What are two specials things that an odontoblast cell has?

Answer 24

Cilia and Microtubules

Question 25

What are the two fibres of the dental pulp?

Answer 25

Type 1 collagen, Type 3 collagen

need to dissolve the collagen to remove the pulp

Question 26

What are the 3 ground substances of the dental pulp?

Answer 26

Glycosaminoglycans
Proteoglycans
Glycoproteins

Question 27

6 vessels of the dental pulp?

Answer 27

• Arterioles
• Capillaries
• Venules
• Arteriovenous shunts
• Lymph vessels
- Capillaries more abundant in the odontoblastic layer where they are more needed to support with nutrients the dentinogenesis

Question 28

3 nerves of the dental pulp?

Answer 28

Myelinated sensory
Unmyelinated sensory
Sympathetic

Question 29

What are the causes of pulptis? (inflammation of pulp)

Answer 29

• caries
• traumas leading to fractures
• cavity preparation
• dental materials
• bacterial leakage at the interface between tooth and restoration
• brushing too much

Question 30

What things need to be done before diagnosing pulptis?

Answer 30

• history
• clinical exams
• special tests
• radiograph examination

Question 31

Where does the dental pulp go down to?

Answer 31

Apical Constuction

Question 32

What special tests can be done for pulpitis?

Answer 32

• pulp vitality (hot GP or endo frost - normal reaction will be sensation which disappears but abnormal is lack of response or bad pain immediately
• radiology test
• electric pulp tester to look at health of vascular supply

Question 33

2 ways to treat pulpitis?

Answer 33

Vital pulp therapy: preserve the pulp by adding restoration to seal pulp
Root canal treatment:
Need to know the length of it (where it ends and touches the periodontal ligament). We have an apex locator to do this. The working length is an instrument which does this).

Question 34

What symptoms are there for irreversible pulpitis?

Answer 34

• pain from cold and hot
• no stimulus for pain
• pain lingers
• awake at night
• pain delayed after stimulus if there is one

Question 35

What are 4 non-odontogenic causes of pulp pain?

Answer 35

Musco-skeletal pain (TMJ disfunction)

Neuropathic pain (trigeminal neuralgia)

Neurovascular pain (migraine, headache)

Autonomic pain (Atypical facial pain)

Question 36

What results in the development of lateral canals?

Answer 36

Vessels of dental pulp

Question 37

5 things on lateral and accessory canals?

Answer 37

Size ranges between 20 and 200um
Are very frequent in the furcation of molars 
Are formed during dentinogenesis 
Amy allow the passage of bacteria 
Sustain endo-perio lesion

Question 38

What is the pulp like in elderly patients?

Answer 38

• has decreased in size (as regular secondary dentine is laid down)
• Is more fibrous
• Remains functional
• Can respond to stimuli
• Can form dentine

Question 39

Is a younger or older patient more at risk in cavity preparation?

Answer 39

Younger patient

Question 40

What are the two types of pulp mineralisation?

Answer 40

• Partial

- Complete

Question 41

Give details on what happens to the pulp in each:

• Type 2 dentinogenesis imperfecta
• Coronal dental dysplasia

Answer 41

Type 2 dentinogenesis imperfecta:
Radiographs demonstrate teeth throughout the dentition have narrow spindly root, rapid sclerosis of the pulp chamber and root canal and bulbous crowns.
Coronal dental dysplasia:
Teeth demonstrate apical extension of pulp chamber producing a flame shape.