microbio of RCS Flashcards
what necrosis occurs in the RCS
liquefactive
is there patholgy without bac in the RCS
NO
RCS provides? why?
The root canal system provides an ideal environment for bacterial colonization
The RCS is warm, moist & nutritious (has lots of substrate) and has a variable but largely anaerobic climate.
This area is now largely protected from the host defenses
bac invasion of pulp initally forms? progresses to?
microabscess progressing to necrosis
basic science most closely associated to endo?
microbio
remaining bac after RCT can cause?
apical periodontitis
first cells to respond to bac at the apex
PMN
chronic inflammation of the apical tissues will form?
periapical granuloma
periapical granuloma formation used to protect bone
what is this? what is happening to the root?
periapical granuloma with resorbtion occuring at the apex
how can RCT alleviate periapical lesions?
removal of the bacteria allows healing to occur
pus of RCS
due to PMN invasion/death, must be drained
most RC infection are caused by?
gram -, anaerobic bac
what do the bacteria of endo infections release? can cause what effects?
LPS/endotoxins, can cause fever, osteolysis and collegenolysis
spp involved with RC infections, most frequent spp?
Gram -, anaerobic
Porphyromonas sp. ( Bacteroides previously)
• Prevotella nigrescens (Bacteroides previously) most frequent in endo infections
• Peptostreptococcus,
• Fusobacterium
• Eubacterium
• Actinomyces
canal walls/ spaces conducive to the formation of?
biofilm
formation of biofilm, responsible for what dx?
Planktonic “floating bacteria” adhere to surface and begin adhesion to one another
Biofilm is adhered to the root canal walls
Formation of biofilm is responsible for apical periodontitis
can only one organism cause infection?
NO, no single spp is repsonsible (polymicrobial dx)
Progression of RC infections
- Carious Lesion or Trauma opens tubules to bacterial invasion
- Bacteria inflame pulp locally
- Inflammation may overcome pulpal defenses and localized abscesses may form in coronal
pulp - Infection increases in pulp and necrosis begins
- Necrosis involves entire RC System
- Infection uses “portals of exit” (apical foramen and lateral canals) to invade peri-radicular tissues (apical periodontitis)
- Periradicular infection occurs beyond apex ( apical abscess )
ludwing angina
medical emergency
due to cellulitis which has spread through fascial planes (sublingual/mandibular)
can eventually increase size and obstruct airway leading to suffocation
BIOFILM must accomplish 6 things to cause disease within the RC System
- MO must adhere to host surfaces
- Obtain nutrients from the host
- Multiply
- Invade tissue
- Overcome host defenses
- Induce tissue damage
BIOFILM
Think complex, variable & constantly changing bacterial infection
BIOFILM may be defined as a multicellular microbial community characterized by cells that are firmly attached to a surface and enmeshed in a self produced matrix of extra cellular polymeric substance (EPS), usually polysaccharide.
_________bacteria appear to be the most common microorganisms in primary
endodontic infections.
gram-, anaerobic
common genera of endo infections
-Porphyromonas
- Prevotella
- Peptostreptococcus
- Streptococcus
- Actinomyces
- Olsenella
- Propionibacterium