CAP Flashcards
(16 cards)
Cause of Apical Periodontitis
Microorganisms colonizing the root canal system play an essential role in the pathogenesis of periradicular lesion.
Kakehashi – germ free rat study directly linked AP to bacteria
Moller – monkey study repeated findings of Kakehashi
Sundqvist – human study further confirmed findings of Kakehashi
Host immunological mechanisms mediate tissue destruction and bone resorption in response to bacterial infection. IL 1,2,6 TNFά
In previously treated cases, bacteria may be present due to missed canal or coronal leakage.
Bacteria involved in initial necrotic case – Gram -, anaerobes
Provotella Lactobacillus
Porphyromonas
Fusobacterium Peptostreptococci
Veillonella Streptococci
Eubaterium *mixed infection, polymicrobial
Propionibacter 3-17 species, symbiotic relationship
Actinomyces
Sundqvist – redirected understanding of canal flora – predominantly anaerobic but mixed with facultative anaerobes.
Baumgartner – apical 5 mm, predominantly anaerobic, BPB found in both coronal and apical area, most common found was P. nigrescens.
Fabricus – number of anaerobes increases with time and apical position
Bacteria involved in previously treated cases – Gram+, facultative anaerobes – treatment resistant
Moller – high incidence of Enterococcus Faecalis (Gr+, facultative) – few or mono species infection
Sundqvist – also found E. Faecalis, frequently as a single species microorganism.
Retreatment success rate ~74%
Nair – found yeast-like microorganisms, therapy resistant
Waltimo – Candida (resistant to many medicaments)
Gomes – Predominantly found same bacteria but also noted that symptomatic cases had anaerobes (pepto, porph., provet, fusos)
Haapasalo – unsealed cases during treatment or multiple appts reveal higher frequency of E. Faecalis.
Species associated with refractory cases
Strep
Enterococci
Staph
Lactobacillus
Proprionibacter
Eubacterium
Actinomyces
Prevotella, Fusobaterium
Causes of E. Faecalis Resistance
Love – because the hide in the tubules
Distel – because they form biofilms
Evans – because the have a proton pump
Haapasalo – Ca(OH)2 – does not kill E. Faecalis / smear layer removal facilitates bacterial invasion into dentinal tubules.
Orstavik – dentin buffers Ca(OH)2
Baumgartner – 2% CHX kills E. Faecalis
Is HIV found in the root canal or apical lesion ?
Torabinejad 1994 JOE – found HIV in the periradicular lesion w/ PCR
Trope 1991 OOO – found HIV in pulp tissue fibroblasts w/ DNA hybridization
Sebeti 2004 JOE – found Herpes simplex, Epstein-Barr & human Cytomegalovirus in periapical lesions. Large lesions showed higher levels.
Are Bacteria associated with symptoms?
YES
- Newton – Bacteroides Melanogenicus are associated with pain, sinus tract and odor
- Hahn – Gr+ cocci & Gr- rods = cold sensitivity
- Sundqvist - >6 species = pain, 5 or less = no pain
NO
1. Baumgartner – no relationship of BPB w/ symptoms
Are bacteria found in periapical lesions? Controversy
YES
1. Iwu – homogenized study
2. Siqueira – Biofilm colonys
3. Sunde –
NO
1. Walton – inflammation resists spread of bacteria, confined to root
2. Nair – bacteria confined to root except
a. Abscess
b. Therapy resistant – actinomyces
c. Infected cysts
3. Holland – bacteria are present when pushed out during RCT
Sjogren – isolated P. propionicum extraradicularly
Waltimo – no candida in AP and is resistant to Ca(OH)2
Torabinejad & Trope – found HIV in AP
Discuss bacterial flora in acute PA abscesses
Langeland – found facultative and anaerobic bacteria/ fuso & streptococcus
Siqueira – described flora as polymicrobial
Sundqvist – BPB’s in abscess – associated with purulence
Bacteremia from RCT
Baumgartner – very low incidence (3.3%) / none if inst. kept w/in canal
Tronstat - ~25% even when instrument is confined to canal
Antibiotic Susceptibility
Baumgartner –
- Pen VK 1st choice – 85% effective
- Amoxicillin – 91% effective
- Amox + Clavulanic acid 100% effective
- Clindamycin 96% effective
- Metronidazole – 45%*
*due to effect only on anaerobic bacteria
Antibiotic effect on Oral Contraceptives
Hersch – only effected by Rifampin, but still advise patient to use alternate BC due to legal issues.
Are bacteria present in traumatized teeth with intact crowns?
YES – Bergenholtz found bacteria 64% of the time/ mixed anaerobic infection, got in through tubules or cracks.
Do Bacteria grow into the tubules?
YES –
Haapasalo – E. Faecalis survived in tubules 10days w/out nutrients
Sen – bacteria penetrate 10-150 microns into the tubules
Oguntebi – bacteria in tubules is a reservoir for future infections
Does anachoresis occur?
YES
- Robinson – 2 requirement – inflammation & bacteria
- Gier – Bacteria are attracted to inflamed pulps
NO
- Doyle
- Moller
Coronal Leakage
- Ray/ Trope – coronal seal more important than quality of RCT
- Siqueira – loss of coronal seal led to contamination w/in 3 days
- Torbinejad – complete contamination of entire length w/in 30 days of loss of seal.
- Newton – recommends retreatment if exposed for 3 months
- Walton – post prepared canals susceptible to endotoxin penetration even faster than bacteria / recommends immediate restoration
Ricucci – 3 year study – no effect from exposure to oral environment, questions role of coronal leakage.
