Biofilm

Question 1

features of biofilm on fissures

Answer 1

streptococci
sacchrolytic
few gram -ve
low anaerobe 
high redox
neutral- acid pH
influenced by saliva

Question 2

features of biofilm on gingival crevice

Answer 2

spirochaetes, and 'unculturables'
proteolytic
many gram-ve
many obligatory anaerobic 
neutral-alkaline pH
influenced by gingival or crevicular fluid

Question 3

dental biofilms are heterogenous. why?

Answer 3

nutrient/ oxygen/ metabolic gradients develop in various environments within mouth

Question 4

define the 4 properties of dental plaque as a biofilm

Answer 4

1. spatial organisation
2. altered gene expression (direct/ indirect)
3. increased TOLERANCE to antimicrobial agents
4. increased RESISTANCE to antimicrobial agents (gene transfer)

Question 5

what is meant by ‘tolerance’ to antimicrobial agents

Answer 5

penetration
inactivation 
novel phenotype
slow growth rate of bacteria in biofilms 
community interactions

Question 6

generally we have a balance, symbiosis, with microbes in dental plaque community. what pressures can cause dysbiosis

Answer 6

immunological: sigA deficiency, neutrophil dysfunction, chemotherapy induced myelosuppression, infection induced myeolosuppression

non-immunologica: xersotima, antibiotics, medication, dietary carbohydrates, increased GCF flow, oral contraceptives?

Question 7

low redox =

Answer 7

anaerobic