Perio Microbio

Question 1

What are the stages of biofilm development?

Answer 1

Adhesion of pioneer bacteria

Colonisation

Accumulation

Complex community formed

Dispersal

Question 2

Important MO’s in healthy oral cavity?

Answer 2

Oral streptococci

Actinomyces

Fusobacterium

Veillonella

Question 3

Important MOs in gingivitis?

Answer 3

Actinomyces

Prevotella intermedia

Fusobacterium nucleatum

Question 4

Important MO’s in periodontitis?

Answer 4

Porphyromas gingivalis

Treponema denticola

Tannerella forsythia

Prevotella intermedia

Question 5

Socransky model red species for perio?

Answer 5

P gingivalis

T denticola

T forsythia

Question 6

What is p gingivalis?

Answer 6

Gram negative

Non-motile rod

Strict anaerobe

Question 7

P gingivalis virulence factors?

Answer 7

Host tissue adherance and invasion
- with fimbrillar adhesions
- long fimbriae = initial attachment
- short fimbriae = cell to cell adhesion

Elaboration of proteases - degradative enzymes
- collagen are
- fibrinolytic etc

Endotoxins - LPS

Capsular polysaccharide
- protection vs host immune cells

outer membrane vesicles
- deliver virulence factors / toxins to host cell

Tissue toxic metabolic by-products
- ammonia
- fatty acids

Question 8

How does p gingivalis evade and manipulate host defences?

Answer 8

Formation of biofilm

Gingipains
- degrade innate immune cell receptors
- degrades cytokines

Induce tissue destruction
- activation of MMPs