An inflammatory disease of microbial aetiology caused by infection of the root canal system which results in bone resorption around the roots
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what is the cause of bone resorption in apical periodontitis
When the pulpal tissue becomes necrotic and infiltrated by micro-organisms which produce toxins to cause inflammatory immunological reactions and end up causing bone resorption
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what is an apical lesion
Represents a protective activity of the host response that is successful most of the time. Attempt to prevent highly pathogenic bacteria present in infected root canals from spreading into adjacent bone and to other more remote places in the body
This pr
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how does a vital pulp offer protection?
Outward movement of dentinal fluid
Tubular contents= act as a blocking mechanism
Tertiary dentine production
Host defence molecules (within the pulp tissue)
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when does dentinal exposure represent a significant route of infection?
when dentine thickness is reduced or dentine permeability increased
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what causes pulpal inflammation?
Micro-organisms (majority of cases)
Mechanical trauma
Chemical irritation
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what are the 2 things needed for apical periodontitis to occur?
necrotic pulp and microbial infection
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what do caries allow (in terms of routes of root canal infection)
Bacterial penetration of tubules and destruction of dentine
Bacterial invasion of dentinal tubules occurs more rapidly with a non-vital (necrotic) pulp compared to a vital pulp
Pulp becomes inflamed when the bacteria is 0.5mm away
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give some examples of mechanical injury to the pulp
a. Traumatic accident (patients falls and damages their teeth)
b. Iatrogenic damage during dental procedure
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give some examples of traumatic accident which may lead to apical periodontitis
trauma to crown
- Impact injury:
Crown remains intact
Microcracks in the enamel allow bacteria to reach the pulp
Blood flow damaged
- fracture of crown: can result in pupal exposure
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give some examples of iatrogenic damage which may lead to apical periodontitis
Excessive orthodontic procedures (if the tooth is moved too quickly through the bone which may disrupt its blood supply and cause damage)
Sub-gingival scaling
Attrition/ abrasion
how does chemical irritation lead to apical periodontitis?
o From erosion
o Inappropriate use of acidic dental materials
Unbound components of resin materials and preparative agents such as acid etchants and bonding agents can affect the subjacent pulp by inducing an inflammatory response
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once the pulp is exposed, it becomes infiltrated with A to form an area of liquefaction necrosis at the side of the exposure. B then persist and C at the side of the necrosis
A= PMNs
B=microbes
C=colonise
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once the pulp is exposed and colonised by microbes it can A or B
A= remain inflamed for a long time
B= undergoes necrosis slowly or rapidly
- Most located in suspension (planktonic bacteria) within the root canal
- Some live in biofilms on canal walls, dentinal tubules, lateral/ accessory canals, isthmi, apical delta
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Other cards in this set
Card 2
Front
what is the cause of bone resorption in apical periodontitis
Back
When the pulpal tissue becomes necrotic and infiltrated by micro-organisms which produce toxins to cause inflammatory immunological reactions and end up causing bone resorption
Card 3
Front
what is an apical lesion
Back
Card 4
Front
how does a vital pulp offer protection?
Back
Card 5
Front
when does dentinal exposure represent a significant route of infection?
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