biofilm and diet

Question 1

what are the early colonizers

Answer 1

streptococcus salivarius, streptococcus mitis, streptococucs oralis

Question 2

with time gram-negative anaerobes appear what are they

Answer 2

prevotella melaninogenica, fusobacterium nucleatum, veillonella spp.

Question 3

resident microflora prevent overgrowth of pathogenic organisms by

Answer 3

-saturation of microbial attachment sites
-effective competition w essential nutrients
-creating unfavorable conditions to invading microbes
-production of inhibitory factors

Question 4

pellicle formation what time

Answer 4

within minutes

Question 5

attachment of early colonizers what time

Answer 5

0-24hrs

Question 6

microcolony formation by co-adhesion and growth

Answer 6

4-24hrs

Question 7

species diversity through microbial succession

Answer 7

1-7 days

Question 8

mature biofilm

Answer 8

1 week or older

Question 9

what is the bridging organism between early and late colonizers

Answer 9

F. nucleatum

Question 10

predominance by what gram is in 5 days

Answer 10

gram -

Question 11

rapid colonization by pioneer species are what

Answer 11

gram + cocci and rods

Question 12

biofilm composed of microcolonies (how much volume) distributed in shaped matrix (how much volume)

Answer 12

microcolonies (15-20% volume)
shaped matrix (75-80% volume)

has voids and water channels also

Question 13

what is the backbone of biofilm

Answer 13

exopolysaccharides (EPS)

Question 14

normal microflora of fissures is sparse or dense, and favored metabolism is derived from what

Answer 14

sparse
sugar breakdown (saccharolytic metabolism)

Question 15

what dominates in fissures

Answer 15

streptococci, w few gram - or anaerobic organisms

Question 16

where is more diverse microflora and there is a lot of what there

Answer 16

gingival crevice
many gram - anaerobic and proteolytic species

Question 17

what is the intermediate combination of microflora of fissures and gingival revices

Answer 17

approximal surfaces

Question 18

streptococcus mutans are what type of bacteria

Answer 18

facultative anaerobic

Question 19

what are the species associated w sever caries

Answer 19

s mutans
actinomyces gerencseriae
bifidobacterium spp
s salivarius
lactobacillus fermentum
veioolonella spp

Question 20

what are 3 cariogenic features of bacteria

Answer 20

-ability to transport fermentable sugars PEP-PTS system
-acidogenic and aciduric
-produce extracellular polysaccharides (EPSs) - glucans and fructans

Question 21

who noted sugar was detrimental to teeth and gingiva

Answer 21

Pierre fauchard

Question 22

what are the monosaccharides and disaccharides

Answer 22

mono - glucose, fructose, galactose
di - sucrose, maltose, lactose

Question 23

caloric bulk sweetener sorbitol

Answer 23

6 carbon sugar alcohol that cannot be utilized by microorganisms that dominate dental plaque

but strains of mutans streptococci, lactobacilli, and other oral microorganisms do ferment sorbitol

Question 24

caloric bulk sweetener xylitol

Answer 24

5 carbon sugar, cannot be fermented by most oral streptococci
exterts bacteriostatic effect on mutans streptococci (creates cell degradation, intracellular vacuoles, and other damages to cell)

Question 25

PEP-PTS does what

Answer 25

sugar (glucose) into membrane of bacteria

Question 26

pyruvate yields

Answer 26

lactic acid accetic acid ethanol formaic acid (decreases pH in biofilm)

Question 27

on cell membrane, have glucosyltransferase and fructosyltransferase which produces what molecules and what for the biofilm

Answer 27

produce glucan and fructan (produces sticky matrix in the biofilm out of sucrose)

Question 28

villanelles species what special about it

Answer 28

do not use glucose or sugar, uses lactic acid from other bacteria, to make acetic acid, formic acid, propionic acid (which lowers pH)

Question 29

can bacteria use xylitol?

Answer 29

bacteria use PEP-PRS system for xylitol to bring it in the cell membrane, but cannot be used by bacteria so it spits out and cannot create ATP xylitol creates vesicles, and vacluoes that promotes destruction of the cell/bacteria