Pathology of Pulpitis

Question 1

What is acute inflammation?

Answer 1

-An immediate response to insult

-There is dilation & an increased permeability of microvasculature

-Exudation of fluid

-Emigration of leukocytes (particularly neutrophils)

Question 2

What are the outcomes of acute inflammation?

Answer 2

-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 3

What is chronic inflammation?

Answer 3

-Prolonged response to persistent stimuli

-Involves lymphocytes, plasma cells & macrophages

-Co-existing injury, inflammation and repair

Question 4

What is pulpitis?

Answer 4

Inflammation of the pulp

Question 5

Describe the aetiology of pulpitis.

Answer 5

The most common cause is microbial

Can also be caused by thermal insult: insufficient cooling of dental hand piece

Chemical insult

Question 6

How can bacteria damage the pulp?

Answer 6

They can damage the pulp through toxins or directly after extension

They gain access through:

Carious cavitation
Attrition/Abrasion/Erosion
Fracture, cracked tooth
Perio-endo lesion
Iatrogenic

Question 7

How can you classify pulpitis?

Answer 7

Acute or chronic (from clinical & histological findings)

Reversible or irreversible (from clinical findings)

Open or closed

Subtotal or generalised

Sterile or infected

Question 8

Why does pulpitis usually result in pulp necrosis with periapical periodontitis as an outcome?

Answer 8

-Because the pulp chamber is enclosed in dental hard tissue with limited blood supply through narrow opening of mature apical foramen

-So an increase in pulpal pressure due to oedema can result in venous stasis which can lead to ischaemia which can lead to necrosis

Question 9

Which local & systemic factors affect healing?

Answer 9

Local:

blood supply
degree of infection
persistent irritation
mobility

Systemic:
age
nutrition
pre-existing medical condition

Question 10

What factors influence the progress of pulpitis?

Answer 10

Host factors:

pulpal anatomy
apical blood flow
pre-existing state of pulp

Irritant:
nature
severity
duration

Question 11

What happens when there’s acute inflammation of the pulp?

Answer 11

• Initial constriction and then dilation of vessels

-Increased blood flow

-Formation of exudate

-Neutrophils (moving from blood vessels to surrounding tissues)

-Oedema

-Destruction of odontoblasts and adjacent pulpal tissue

-Variable necrosis

-Variable abscess formation (look at pic for more info)

Question 12

What happens when there is chronic inflammation of the pulp?

Answer 12

• Lymphocytes, plasma cells, macrophages
• Variable necrosis

Question 13

What does an inflamed pulp look like histologically:

Answer 13

• Dense acute inflammatory infiltrate of neutrophils
• Presence of chronic inflammatory cells such as : plasma cells and lymphocytes

Question 14

What does a necrotic pulp look like histologically?

Answer 14

The pulp is dead

Question 15

What is the main symptom of pulpitis?

Answer 15

-Pain

-Pulps of individual teeth are not precisely represented in the sensory cortex, therefore pain can be poorly localised.

-Can be felt in the upper or lower jaw or more rarely distant sites such as the ear

-Pain is not provoked by pressure to surface of tooth (biting, percussion) as infection/inflammation not spread to periapical tissues

Question 16

What are the symptoms of reversible pulpitis?

Answer 16

Hypersensitive to hot and cold

Pain subsides on removal of the stimulus

Positive response to vitality testing

Question 17

What are the symptoms of irreversible pulpitis?

Answer 17

As inflammation progresses, pain becomes persistent and spontaneous

Reduced or no response to vitality testing

Question 18

What’s is Vitality testing?

Answer 18

technique that is uses either thermal or electrical stimulation to determine where there a tooth is vital or nonvital.

Question 19

What would you see in reversible pulpitis?

Answer 19

-Hyperaemia

-Oedema

-Chronic inflammatory cells underlying the area of affected dentinal tubules

-Scattered acute inflammatory cells are found occasionally

-Can see reparative secondary dentine

Question 20

What would you see in irreversible pulpitis?

Answer 20

-Often congestion of venules that results in focal necrosis

-Surrounding pulp tissue can show fibrosis

-Mixture of neutrophils, plasma cells, lymphocytes and macrophages

Question 21

How would you treat reversible & irreversible pulpitis?

Answer 21

Reversible pulpitis is treated by removal of the local irritant

Irreversible pulpitis treated by tooth extraction or root canal treatment

Question 22

Is pulpitis usually open or closed?

Answer 22

The vast majority is usually closed

Question 23

What is open pulpitis and where might you see it?

Answer 23

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 24

What is chronic hyperplastic pulpitis (pulpal polyp)?

Answer 24

-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 hyper plastic 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.