Pathology of Pulpitis Flashcards
What is acute inflammation?
-An immediate response to insult
-There is dilation & an increased permeability of microvasculature
-Exudation of fluid
-Emigration of leukocytes (particularly neutrophils)
What are the outcomes of acute inflammation?
-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
What is chronic inflammation?
-Prolonged response to persistent stimuli
-Involves lymphocytes, plasma cells & macrophages
-Co-existing injury, inflammation and repair
What is pulpitis?
Inflammation of the pulp
Describe the aetiology of pulpitis.
The most common cause is microbial
Can also be caused by thermal insult: insufficient cooling of dental hand piece
Chemical insult
How can bacteria damage the pulp?
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
How can you classify pulpitis?
Acute or chronic (from clinical & histological findings)
Reversible or irreversible (from clinical findings)
Open or closed
Subtotal or generalised
Sterile or infected
Why does pulpitis usually result in pulp necrosis with periapical periodontitis as an outcome?
-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
Which local & systemic factors affect healing?
Local:
blood supply
degree of infection
persistent irritation
mobility
Systemic:
age
nutrition
pre-existing medical condition
What factors influence the progress of pulpitis?
Host factors:
pulpal anatomy
apical blood flow
pre-existing state of pulp
Irritant:
nature
severity
duration
What happens when there’s acute inflammation of the pulp?
- 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)
What happens when there is chronic inflammation of the pulp?
- Lymphocytes, plasma cells, macrophages
- Variable necrosis
What does an inflamed pulp look like histologically:
- Dense acute inflammatory infiltrate of neutrophils
- Presence of chronic inflammatory cells such as : plasma cells and lymphocytes
What does a necrotic pulp look like histologically?
The pulp is dead
What is the main symptom of pulpitis?
-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
What are the symptoms of reversible pulpitis?
Hypersensitive to hot and cold
Pain subsides on removal of the stimulus
Positive response to vitality testing
What are the symptoms of irreversible pulpitis?
As inflammation progresses, pain becomes persistent and spontaneous
Reduced or no response to vitality testing
What’s is Vitality testing?
technique that is uses either thermal or electrical stimulation to determine where there a tooth is vital or nonvital.
What would you see in 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
What would you see in 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
How would you treat reversible & irreversible pulpitis?
Reversible pulpitis is treated by removal of the local irritant
Irreversible pulpitis treated by tooth extraction or root canal treatment
Is pulpitis usually open or closed?
The vast majority is usually closed
What is open pulpitis and where might you see it?
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
What is chronic hyperplastic pulpitis (pulpal polyp)?
-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.
