Oral Microbes in Health and Disease

Question 1

what is the microbiome

Answer 1

how the bateria interact with both each other and their surroundings
the sum of microbes, their genetic information and the environment in whcih they interact

Question 2

what holds together the chains of cocci on strep mutans

Answer 2

exopolysaccharide

Question 3

what are the virulence factors of strep mutans

Answer 3

acid production
acid tolerance
extracellular polysaccharide synthesis
biofilm formation

Question 4

describe the critical pH

Answer 4

The critical pH is the pH below which the enamel starts to dimineralize. Gradually over the following 30 minutes the pH of the mouth begins to return to neutrality and the dissolving of enamel ceases and the products of saliva begins to remineralize any dissolved portions of the enamel. Conditions below 5.5 pH favour strep mutans.

Question 5

describe symbiosis

Answer 5

the microbiome is in harmony with the host and there is ecological balance
associated with good health

Question 6

describe dysbiosis

Answer 6

higher net acid production leading to enamel demineralisation
catastrophe as it leads to disease

Question 7

describe symbiotic dental caries

Answer 7

plaque is dominated by commensal bacteria, the net acid production is low
there is no net demineralisation

Question 8

describe dysbiotic dental caries

Answer 8

plaque dominated by pathogenic bacteria
net acid production is high
enamel demineralises

Question 9

describe prophrymonas gingivalis

Answer 9

gram negative bacilli with black pigmenting anaerobe
susceptible to metronizadole and pencillin antibiotics

Question 10

what are the virulence factors of porphyromonas gingivalis

Answer 10

increased resistance to phagocytosis
ability to cause an inflammatory reaction