DP07 pathology of periapical disease & radicular cysts Flashcards
(15 cards)
What is periapical disease?
Irritation of the PDL at the apex of the tooth - apical periodontitis
What does the effects of surgical exposures of dental pulps in gnotobiotic (germ-free) and conventional lab rats cause show?
Micro-organisms have an essential role in the pathogenesis of periapical lesions
Absence or presence of a microbial flora is the major determinant of healing
What are some causes of periapical irritation?
Pulpitis with pulp infection
Trauma
Iatrogenic
What causes of pulpitis with pulp infection are there?
Bacteria infecting the pulp subsequence to injury
Caries, fractured tooth, pulpal exposure during cavity prep
What things can cause trauma to the teeth?
Occlusal - high restoration, bruxism, biting on hard object unexpectedly
Orthodontic tooth movement
Direct blow to tooth
What things can cause iatrogenic periapical irritation?
Overinstrumentation during root canal preparation
Chemical irritation from medicaments and root filling materials
Failed endodontic treatment
Root perforation
What are the sequelae to a non-vital tooth?
Acute apical periodontitis –> acute alveolar abscess –> 1. cellulitis 2. chronic abscess
Chronic apical periodontitis –> periapical granuloma –> radicular cyst
Periapical granuloma –> acute alveolar abscess
Chronic abscess –> radicular cyst
What does the response to periapical inflammation depend on?
Type of irritant
Severity of irritant
Duration of irritant
Host defence
Usually bacteria responsible for AP are not able to establish themselves in a lesion because they are held back and eliminated by host defence. How is AP normally initiated?
AP normally initiated and maintained by release of bacterial by-products produced during growth and disintegration of bacteria within confines of root canal space
What are the exceptions to when bacteria might be found in the infective area?
Periapical abscesses - bacteria may be found within the exudate.
Bacteria may invade and survive long term causing external root colonisation, periapical actinomycosis, yellow sulphur granules
What is transient AAP?
Inflammation of short duration initiated within healthy periapical tissues in response to irritants
What is the histology of transient AAP?
Acute inflammation at the apex, vascular dilation, oedema, infiltration of inflammatory cells
How does transient AAP present clinically?
Pain to external pressure, tooth feels elevated in socket
How does transient AAP present radiographically?
Normal or slight PDL widening
