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2012-11-30 19:04:50

endo micro
Show Answers:

  1. When is bacterial infection irreversible?
    Once it hits the pulp
  2. How do bacteria invade the pulp?
    Bacteria advance through the dentinal tubules
  3. What are some portals of entry for bacteria to the pulp?
    • Caries
    • cracks
    • trauma
  4. where are the microbes located in endodontic infections?
    • Resorption lacunae
    • periodontal plaque
    • necrotic pulp tissue (major site)
    • Dentinal tubules
  5. What is the etiologic agent of pulpal infection and periradicular lesion formation?
  6. What caused necrosis of the pulp?
    The severance of  blood supply (no metabolic activity)
  7. What do all teeth with periapical osteitis have?
    • They all harbor bacteria.
    • No bacteria were isolated from teeth without it
    • Most samples had more than one bacterial strain
  8. which bacteria are prevalent in pulpal infection?
    • Obligate anaerobic bacteria
    • Fusobacterium, Bacteroides, Peptococcus, Peptostreptococcus
  9. When does a periapical immune response occur?
    • When the infection overwhelms pulpal defenses and destroys the pulp tissue
    • The periapical respnse is the second line of defense
  10. What causes a periapical lesion?
    The accumulation of inflammatory cells and bone destruction
  11. Which bacteria are associated with caries? Deep caries?
    • Streptococcus mutans
    • Streptococcus sobrinus
    • Actinomyces
    • Deep: mostly strict anaerobes
  12. What did the necrotic dental pulp study of 1976 show?
    • 1. Most samples had more than one bacterial strain
    • 2. Predominance of obligate anaerobic bacteria
    • fusobacterium, bacteroides, eubacterium, peptostreptococcus
  13. What is the root canal flora of noncarious but necrotic teeth with a diseased apex?
    • It is dominated (90%+) by obligate anaerobes
    • fusobacterium, porphyromonas, prevotella, eubacterium
  14. What is the microbial composition of carious teeth with necrotic pulp and diseased periapex?
    It is less dominated (<70%) by strict anaerobes
  15. What are some species of polymicrobial endodontic infections?
    • 1. Porphyromonas, black-pigmented (gingivalis, endodontalis)
    • 2. Prevotella, black-pigmented (denticolla, intermedia, nigrescenst)
    • 3.Prevotella, non-pigmented (buccae)
  16. Can fungi be present at the foramen of a root canal with a periapical granuloma?
  17. Possible nutritional relationships between bacteria inthe root canal
  18. What is the active component of Lipopolysaccharide (LPS) implicated in bacterial virulence?
    Lipid A is the active component. It also has an O-specific chain
  19. How can you maximize endodontic prognosis?
    By eliminating the microorganisms from infected root canals
  20. What is the core concept of endodontic treatment?
    chemomechanical debridement  and biomechanical preparation, followed by an obturation of the root canal system
  21. How do we treat vital pulp?
    with a pulpectomy
  22. How do we treat necrotic pulp?
    We treat by disrupting the microbial ecosystem by bacterial removal, as well as their byproducts and substate, from the canal system
  23. What do you do for emergency treatment of necrotic pulp?
    • Multifaceted approach
    • 1. Debridement of pulp space
    • 2. Drainage of canal or soft tissue
    • 3. Pharmacotherapeutics
  24. What do you do during an average endo treatment?
    • 1. endo access
    • 2. Determine working length
    • 3. disinfect root canal
    • 4. intracanal medication
    • 5. place root filling
    • 6. restoration
    • 7. observation and follow up
  25. Tooth and rubber dam disinfection materials
    • 1. 30% H202
    • 2. 5% iodine tincture or .5% CHX
    • 3. 6% Sodium Hypochlorite
  26. Root canal irrigants/disinfectants
    Sodium hypochloride, Chlorhexidine
  27. Removal of smear layer compounds
    • Irrigate with distilled water, then..
    • Citric Acid, EDTA, MTAD
  28. What do you use to medicate between appointments? What does it do?
    • calcium hydroxide
    • Hydrolyzes lipid moiety of bacterial LPS, alters properties
  29. What usually happens to periapical lesions after treatment is complete?
    The lesions absolve through repair and regeneration
  30. Which has a higher success rate after RCT, + or - cultures?
    - cultures (88.6%) have more than + (75%)
  31. What complicates the success of root canal therapies?
    • The presence of bacteria can greatly affect the sucess
    • The micro flora of failed RCT is different from untreated teeth
  32. What is the most commonly recovered bacteria in failed root canals?
    Enterococcus faecalis
  33. Which factors of microbes have a negative impact on prognosis of treatment?
    • Infection at time of root filing
    • Size of preperative periapical lesion
  34. Which medical condition reduces the success of endo treatment?