W9 - Endodontic Bacteriology - Stoll

Question 1

Usual ways of tooth infection (3)

Answer 1

1. Pulp exposition by attrition or trauma
2. Caries
3. Periodontal Disease

Question 2

What are the stages of biofilm development?

Answer 2

A. Pellicle Formation

B. Initial Adhesion

C. Maturation

D. Dispersion

Question 3

Describe how the bacterial species change as the biofilm ages

Answer 3

Spectrum of species changes from aerobic to anaerobic bacteria

• AA Increase

Question 4

What is the primary way for bacteria to progress through tooth

Answer 4

Through dentinal tubules

Question 5

How do bacteria travel thru tubules? (sizes and method)

Answer 5

Tubule diameter → 1-2 um, thus 5-20 bacteria (0.1 um) can fit in

Propagation happens through adhesion and multiplication

Question 6

What type of bacterial species are in deep dentine lesions

Answer 6

• Inside of tubules = very low O2
• Facultative and strict anaerobes remain
• Streptococci and Lactobacilli (moreso than streptococci)

Question 7

What is the first reaction when bac approaches pulp

Answer 7

Formation of secondary dentine

Question 8

What is the second reaction when bac approaches pulp

Answer 8

Pulpitis occurs → First step is hyperaemia

• Blood vessels are widened and filled with erythrocytes

Question 9

What happens histologically during pulpitis (6)

Answer 9

1. Hyperaemia → blood vessels are widened and filled with erythrocytes
2. Acute pulpitis → spaces between cells are filled with serum
3. Acute pulpitis → Blood vessels become permeable for leukocytes
4. Acute pulpitis → Microabscesses
5. Necrobiosis
6. Necrosis

Question 10

Answer 10

Formation of tertiary dentine

Question 11

Answer 11

Hyperaemia

Question 12

Answer 12

Spaces between cells are filled with serum

(part of acute pulpitis)

Question 13

Answer 13

Blood vessels becoming permeable for leukocytes

Question 14

Answer 14

Microabscesses from pulpitis

Question 15

Answer 15

Necrobiosis → Bacteria has invaded pulp

Question 16

Answer 16

Necrosis

• necrotic and infected pulp
• complete destruction of pulpal tissue

Question 17

Answer 17

Development of biofilm in the canal walls

• Necrotic tooth

Question 18

What can happen once tooth is necrotic and biofilm has formed in canal?

Answer 18

Bacterial will travel outwards through tubules

• Must chemo-mechanically remove and then use EDTA for smear layer

Question 19

Chronic vs acute apical periodontitis

Answer 19

Chronic - Low virulence, good defence

Acute + abscess - High virulence, low defence

Question 20

How must periapical abscesses be diagnosed?

Answer 20

Presence of pus in bone

• Almost impossible to diagnose clinically → will most likely be called acute periapical periodontitis

Question 21

How does chronic apical periodontitis differ from acute apical periodontitis (NOT abscess)?

Answer 21

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

Question 22

What occurs when there is equilibrium between virulence and defense

Answer 22

Chronic apical abscess

• May present with or without sinus tract

Question 23

Answer 23

Chronic apical abscess

Question 24

Can there be a vaccine against endodontic bacteria?

Answer 24

No - cannot create vaccine due to large spectrum of bacterial species present

Question 25

How do retreated and problematic endo cases differ in terms of bacteriology in the canal?

Answer 25

Increase in gram-positive streptococci

Question 26

What are the 2 problematic species in endo

Answer 26

E Faecalis

C Albicans

Question 27

Why is E Faecalis a problematic species

Answer 27

Has a correlation to increased failures

Question 28

Why is E faecalis and C Albicans problematic? (3)

Answer 28

Resistant to CaOH

High penetration rate into tubuli

Forms biofilms