Pathology of pulpitis Flashcards
When does acute inflammation happen and what happens?
It happens immediately in response to an insult/stimuli.
Dilation and increased permeability of microvasculature.
Exudation (oozing) of fluid
Emigration of leukocytes (particularly neutrophils)
What are the potential outcomes of acute inflammation? (3)
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 and what cells are involved?
Prolonged response to persistent stimuli
Involves lymphocytes, plasma cells and macrophages
Co-existing injury, inflammation and repair
What is pulpitis?
Inflammation of the pulp
What can lead to pulpitis? (3 ways)
Microbial
Thermal (e.g. insufficient cooling of handpiece)
Chemical
How may bacteria gain access to the pulp? (5)
- Carious cavitation
- Attrition/abrasion/erosion
- Fracture, cracked tooth
- Perio-endo lesion
- Iatrogenic (caused by the clinician)
Name the 5 ways pulpitis can be classified
- Acute or Chronic (clinical and histological)
- Reversible or irreversible (clinical)
- Open or closed
- Subtotal or generalised
- Sterile or infected
Why is inflammation in the pulp chamber different to inflammation in other parts of the body? (2)
- Pulp chamber enclosed in dental hard tissue with limited blood supply through the narrow opening of mature apical foramen
- Increase in pulpal pressure due to oedema:
Venous stasis > Ischemia > Necrosis
What is usually the result of pulpitis?
- Pulpitis usually results in pulp necrosis with periapical periodontitis as an outcome
What local factors affect healing in terms of pulpitis?
Blood supply
Degree of infection
Persistent irritation
Mobility
What systemic factors influence healing in terms of pulpitis?
Age
Nutrition
Pre-existing medical conditions
What HOST FACTORS influence the progress of pulpitis? (3)
Pulpal anatomy
Apical blood flow
Pre-existing state of pulp
What IRRITANT FACTORS influence the progress of pulpitis? (3)
Nature
Severity
Duration
Why is necrosis more common in pulp that other parts of the body?
Due to the local anatomy
What happens in acute inflammation in the pulp? (8)
- Initial constriction THEN dilation of vessels
- Increased blood flow
- Formation of exudate
- Neutrophils
- Oedema
- Destruction of odontoblasts and adjacent pulpal tissue
- Variable necrosis
- Variable abscess formation
What is in an abscess that may be formed in acute inflammation of the pulp?
Collection of exudate consisting of neutrophils, the liquefied debris of necrotic cells and oedema fluid
What happens in chronic inflammation in the pulp?
Presence of lymphocytes, plasma cells, macrophages
Variable necrosis
Why is it hard to diagnose which tooth may have pulpitis?
Because pulps of individual teeth are not precisely represented in the sensory cortex - so it is hard to localise and pain may refer.
Pain not provoked by pressure to tooth surface as infection/inflammation not spread to periapical tissues
What may indicate that the patient is suffering from reversible pulpitis? (3)
- Hypersensitive to hot AND cold
- Pain subsides on removal of stimulus
- Positive response to vitality testing
What may indicate that the patient is suffering from irreversible pulpitis? (2)
Pain is persistent and spontaneous.
Reduced or no response to vitality testing.
Describe the histology of reversible pulpitis (5)
- Hyperaemia
- Oedema
- Chronic inflammatory cells underlying the area of affected dentinal tubules
- scattered acute inflammatory cells are found occasionally
- Can see reparative secondary dentine
Describe the histology of irreversible pulpitis (3)
- often congestion of venules that results in focal necrosis
- Surrounding pulp tissue can show fibrosis
- Mixture of neutrophils, plasma cells, lymphocytes and macrophages
What is the treatment for reversible pulpitis?
Removal of local irritant
What is the treatment for irreversible pulpitis?
Tooth extraction or RCT
Is the vast majority of pulpitis open or closed?
Closed
What happens in open pulpitis?
Pulp survives chronically inflamed beneath a large exposure.
This is despite heavy infection.
Often associated with open apices giving a good blood supply (seen in children)
What is chronic hyperplastic pulpitis (pulpal polyp)?
- 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 - may or may not be covered with stratified squamous epithelium (that has migrated from adjacent gingiva)
[granulation tissue can develop its own blood vessels] - 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)
In pulpal polyps, what may reduce the chance of pulpal necrosis?
If the apex is open
Where are pulpal polyps most likely to develop?
In deciduous molars or first permanent molars in children
they have large pulpal chambers
Outline some pulpal changes that may occur (3)
- Fatty change
- Fibrosis
- Calcified material (e.g. pulp stones, metaplastic ossification.)
