plaque and periodontal microbiology

Question 1

what are the classifications of plaque?

Answer 1

supragingival and subgingival

Question 2

composition of plaque as a biofilm.

Answer 2

microcolonies of bacteria and matrix or glycocalyx

Question 3

matrix is mostly what?

Answer 3

water and aqueous solutes

Question 4

the organic part of matrix is generally what?

Answer 4

mixture of exopolysacharides, proteins, salts, and cell materials

Question 5

the inorganic component of matrix is what?

Answer 5

mostly calcium and phosphorus

Question 6

what do the exopolysacharides do?

Answer 6

maintain integrity of biofilm

Question 7

whats roles does the matrix play?

Answer 7

protects microbes, prevents them from desicating, acts as a buffer

Question 8

what allows cells to aggregate?

Answer 8

fimbria, pilli, bacterial capsule

Question 9

whats quorum sensing?

Answer 9

involves regulation of expression of specific genes through the accumulation of signaling compounds that mediate intercellular communication

Question 10

3 phases of plaque formation

Answer 10

pellicle formation, initial adhesion, colonization

Question 11

aquired pellicle

Answer 11

has peptides, proteins and glycoproteins and attaches to all the hard and soft tissues( formation starts within a few minutes of oral hygiene)

Question 12

what are the 2 layers of the pellicle

Answer 12

thin basal layer, thick globular layer

Question 13

which color are the primary colonizers?

Answer 13

yellow, green, purple, blue

Question 14

can periodontal pathogens fulfill kochs postulates?

Answer 14

no!

Question 15

what are socranskys postulates?

Answer 15

association-pathogens are found in higher number in diseased people
elimination- elimination of pathogen makes disease go away
host response- there should be evidence of a host response to a specific pathogen that is causing tissue damage
virulence factors- pathogen may function to damage the host tissues
animal studies- pathogen affects animals as well

Question 16

indigenous theory of periodontal bacteria origin

Answer 16

resident flora overgrow and become opportunistic pathogens causing periodontal diseases

Question 17

exogenous theory or periodontal bacterial origin

Answer 17

plaque accumulations dont doesnt itself cause problems. The patient must also become infected with specific periodontal pathogens that are transmitted from another source

Question 18

Therapy for indigenous therapy

Answer 18

complete elimintation is impossible. You just have to suppress them so the normal host immune function can spark into action

Question 19

therapy for exogenous therapy

Answer 19

complete elimination from oral cavity via antibiotics

Question 20

non-specific plaque hypothesis

Answer 20

the quantitiy of the bacteria is what causes the problem.

Question 21

whats wrong with the non-specific plaque hypothesis?

Answer 21

it describes gingivitis but not periodontitis. ( not all gingivitis progresses to periodontitis)

Question 22

specific plaque hypothesis

Answer 22

specific bateria produce noxious products which mediate periodontal destruciton

Question 23

what about the microbial shift hypothesis?

Answer 23

falls within the specific plaque hypothesis. A shift in beneficial commensal species to an increase of specific pathogens which are associated with periodontitis

Question 24

Ecological plaque hypothesis

Answer 24

environmental changes favor the growth of gram negative and proteolytic species of bacteria which cause inflammation and tissue changes. This cause greater degree of tissue damage and periodontitis

Question 25

A. actinomycetemcomitans

Answer 25

5 serotypes, associted with LJP, important in refractory periodontitis, invades gingival connective tissue. produces leukotoxin

Question 26

p. gingivalis

Answer 26

virulence factors are fibrial adhesins, LPSs capsule, collagenase and trypsin like enzymes

Question 27

P intermedia

Answer 27

p nigrescens is a subgroup which is more virulent.