W9 - Endodontic Bacteriology - Stoll Flashcards
Usual ways of tooth infection (3)
- Pulp exposition by attrition or trauma
- Caries
- Periodontal Disease
What are the stages of biofilm development?
A. Pellicle Formation
B. Initial Adhesion
C. Maturation
D. Dispersion
Describe how the bacterial species change as the biofilm ages
Spectrum of species changes from aerobic to anaerobic bacteria
- AA Increase
What is the primary way for bacteria to progress through tooth
Through dentinal tubules
How do bacteria travel thru tubules? (sizes and method)
Tubule diameter → 1-2 um, thus 5-20 bacteria (0.1 um) can fit in
Propagation happens through adhesion and multiplication
What type of bacterial species are in deep dentine lesions
- Inside of tubules = very low O2
- Facultative and strict anaerobes remain
- Streptococci and Lactobacilli (moreso than streptococci)
What is the first reaction when bac approaches pulp
Formation of secondary dentine
What is the second reaction when bac approaches pulp
Pulpitis occurs → First step is hyperaemia
- Blood vessels are widened and filled with erythrocytes
What happens histologically during pulpitis (6)
- Hyperaemia → blood vessels are widened and filled with erythrocytes
- Acute pulpitis → spaces between cells are filled with serum
- Acute pulpitis → Blood vessels become permeable for leukocytes
- Acute pulpitis → Microabscesses
- Necrobiosis
- Necrosis
Formation of tertiary dentine
Hyperaemia
Spaces between cells are filled with serum
(part of acute pulpitis)
Blood vessels becoming permeable for leukocytes
Microabscesses from pulpitis
Necrobiosis → Bacteria has invaded pulp
Necrosis
- necrotic and infected pulp
- complete destruction of pulpal tissue
Development of biofilm in the canal walls
- Necrotic tooth
What can happen once tooth is necrotic and biofilm has formed in canal?
Bacterial will travel outwards through tubules
- Must chemo-mechanically remove and then use EDTA for smear layer
Chronic vs acute apical periodontitis
Chronic - Low virulence, good defence
Acute + abscess - High virulence, low defence
How must periapical abscesses be diagnosed?
Presence of pus in bone
- Almost impossible to diagnose clinically → will most likely be called acute periapical periodontitis
How does chronic apical periodontitis differ from acute apical periodontitis (NOT abscess)?
Chronic is the balance of virulence and defense in favour of defense
Acute is the balance in favour of virulence
- Chronic will have granuloma with lymphocytes, plasma cells, monocytes & macrophages
What occurs when there is equilibrium between virulence and defense
Chronic apical abscess
- May present with or without sinus tract
Chronic apical abscess
Can there be a vaccine against endodontic bacteria?
No - cannot create vaccine due to large spectrum of bacterial species present
How do retreated and problematic endo cases differ in terms of bacteriology in the canal?
Increase in gram-positive streptococci
What are the 2 problematic species in endo
E Faecalis
C Albicans
Why is E Faecalis a problematic species
Has a correlation to increased failures
Why is E faecalis and C Albicans problematic? (3)
Resistant to CaOH
High penetration rate into tubuli
Forms biofilms
