Pathology of Pulpitis

Question 1

What happens in term of acute inflammation and what are the outcomes for this?

Answer 1

Acute inflammation:

• Immediate and response to insult
• Dilation and increased permeability of microvasculature
• Exudation of fluid
• Emigration of leukocytes (particularly neutrophils)

Outcomes:
Complete resolution occurs with regeneration of native cells and restoration to normalcy
Healing by connective tissue replacement (fibrosis) occurs after substantial tissue destruction and in non-regenerating tissues
Progresses to chronic inflammation

Question 2

What happens in terms of chronic inflammation with pulpitis?

Answer 2

Prolonged response to persistent stimuli
Involves lymphocytes, plasma cells and macrophages
Coexisting injury, inflammation and repair

Question 3

What are the 3 main causes of pulpitis?

Answer 3

• Microbial
• Thermal
• Chemical

Question 4

Explain how microbiology causes pulpitis?

Answer 4

Bacteria can damage the pulp through toxins or directly though extension.
They gain access through:
Carious cavitation (most common)
Attrition/abrasion/erosion
Fracture
Perio-endo lesion
Iatrogenic (caused by dental instruments)

Question 5

What are the 5 ways that pulpitis is classified?

Answer 5

1. Acute or chronic
2. Reversible or irreversible
3. Open or closed
4. Subtotal or generalised
5. Sterile or infected

Question 6

Why is inflammation in the pulp different to that in the skin?

Answer 6

Pulp cannot expand as surrounded by hard tissue

Not many blood vessels meaning limited bloody supply through apical foramen

Increase in pulpal pressure is then due to swelling. This is venous stasis leading to ischemia leading to necrosis

Pulpitis usually results in pulp necrosis with periapical periodontitis as an outcome.

Question 7

What are the local and systemic factors that influence the healing of pulpitis?

Answer 7

Local

• Blood supply
• Degree of infection
• Persistant irritation
• Mobility

Systemic

• Age
• Nutrition
• Pre-existing medical condition

Question 8

What factors affect the progress of pulpitis?

Answer 8

Host factors:

• Pulpal anatomy
• Apical blood flow
• Pre-exisiting state of pulp

Irritant:

• Nature
• Severity
• Duration

Question 9

Give the two details on acute and chronic pulpitis

Answer 9

Similar to inflammation in other parts of the body.

Necrosis is more common here due to the local anatomy

Question 10

Give the names of things that occur during acute inflammation in the pulp

Answer 10

• Initial constriction then dilation of vessels
• Increased blood flow
• Formation of exudate
• Neutrophils (lots)
• Oedema
• Destruction of odontoblasts and adjacent pulpal tissue
• Variable necrosis
• Variable abscess formation

Question 11

Give the details of 2 extra things that occur in chronic inflammation

Answer 11

• Lymphocytes, plasma cells, macrophages

- Variable necrosis of pulp

Question 12

What are some pain symptoms of pulpitis?

Answer 12

Pain
•Pulps of individual teeth not precisely represented in the sensory cortex. Therefore pain can be poorly localized. Can be felt in the upper or lower jaw or more rarely distant sites such as the ear
•Pain not provoked by pressure to surface of tooth (biting, percussion) as infection/inflammation not spread to periapical tissues

Question 13

What are the differences in symptoms between reversible and irreversible pulpitis?

Answer 13

• Reversible pulpitis: Hypersensitive to hot and cold. Pain subsides on removal of the stimulus. Positive response to vitality testing.
• Irreversible pulpitis: As inflammation progresses pain becomes persistent and spontaneous. Reduced or no response to vitality testing.

Reversible pulpitis
•Hyperaemia, oedema,
•Chronic inflammatory cells underlying the area of affected dentinal tubules
•Scattered acute inflammatory cells are found occasionally
•Can see reparative secondary dentine

Irreversible pulpitis
•Often congestion of venules that results in focal necrosis
•Surrounding pulp tissue can show fibrosis
•Mixture of neutrophils, plasma cells, lymphocytes and macrophages

Question 14

What are the typical treatments which are reversible and irreversible?

Answer 14

Reversible = removal of local irritant (usually caries removal)

Irreversible = tooth extraction or root canal treatment

Question 15

Give some details on open/closed pulpitis?

Answer 15

Open or closed pulpitis
•Vast majority of pulpitis closed
•In open pulpitis, pulp survives chronically inflamed beneath a large exposure despite heavy infection
•Often associated with open apices (see in children) giving a good blood supply

Question 16

What is chronic hyperplastic pulpitis? (pulpal polp)

Answer 16

• Deciduous molars or first permanent molars in children (have large pulp chambers)
• Large carious exposures of the pulp in which entire dentinal roof often missing
• Chronic inflammation produces hyperplastic granulation tissue that extrudes from the pulp chamber
• The apex may be open and reduces the chance of pulpal necrosis
• Tooth is asymptomatic except for a possible feeling of pressure when it is placed into masticatory function
• The surface of the polyp may or may not be covered with stratified squamous epithelium that can migrate from adjacent gingiva

Can get fat, fibrosis or calcified material in pulp.