Lecture 6&7- Role of antibiotics in Periodontal therapy

Question 1

when is it reasonable to consider use of antibiotics to treat chronic periodontitis

Answer 1

poor response to SRP and contin. att loss

patients whose subgingival biofilm tests positive for P.g. or A.a

severe cases with generalized deep pocket depths

Question 2

rationale for using antibiotics

Answer 2

some perio pathogens invade soft tissue (a.a., p.g., p.i.)

difficult to remove biofilm from deep pockets or furcations

Question 3

why is chronic periodontitis not routinely treated with antibiotics?

Answer 3

SRP can elim most subgingival bacteria

innate and acquired host defense mechanisms are usually effective in coping with bacteria

small benefit might not be worth the risks (resistance)

Question 4

bacteria in biofilm are resistant to antibiotics so subgingival biofilm MUST be ….. by …. prior to using antibiotics

Answer 4

disrupted

SRP

Question 5

antibiotics used in perio therapy

Answer 5

penicillins
metronidazole
tetracyclines
clindamycin
macrolides

Question 6

tetracycline is a … inhibitor which works on ….

Answer 6

30S

protein synthesis

Question 7

Erythromycin (macrolides) and clindamycin are … inhibitors that work on…

Answer 7

50S

protein synthesis

Question 8

bactericidal agents .. bacteria

Answer 8

kill

Question 9

bacteriostatic agents …

Answer 9

slow bacterial growth

Question 10

narrow spectrum antibiotics are effective against specific families and is spares …. an example is …

Answer 10

gut microbiota

metronidazole

Question 11

broad spectrum acts against a wide range of clinically important bacteria, an example is …

Answer 11

tetracycline

Question 12

are penicillins bactericidal or bacteriostatic?

Answer 12

bactericidal

Question 13

penicillins are inactivated by…

Answer 13

beta-lactamases

Question 14

penicillins don’t inhibit all … strains and they dont penetrate … very well

Answer 14

a.a.

epithelial cells

Question 15

amoxicillin has a … spectrum, enhanced tissue penetration and good activity against gram neg. bacteria

Answer 15

broad

Question 16

Augmentin is …. combined with ….

Answer 16

amoxicillin
beta-lactamase inhibitor

(gets around the weakness of penicillins)

Question 17

metronidazoles is a … spectrum … agent that is active against ….

Answer 17

narrow
bactericidal
strict anaerobes

Question 18

metronidazole inhibits ..

Answer 18

DNA synthesis

Question 19

metronidazole’s activity against a.a.

Answer 19

less potent (not ideal)

Question 20

are penicillins and metronidazoles cheap or expensive

Answer 20

cheap

Question 21

tetracyclines (minocycline and doxycycline) are … agents against most periodontal pathogens and have a …. spectrum of activity

Answer 21

bacteriostatic

broad

Question 22

tetracyclines (doxy and mino) can reach higher levels in … than …

Answer 22

GCF

blood serum

Question 23

tetracyclines inhibit …. which mediates collagen breakdown in periodontitis

Answer 23

collagenase (MMPs specifically)

Question 24

tetracyclines are actively accumulated by …. (3)

Answer 24

oral epithelial cells
gingival fibroblasts
PMNs

Question 25

Fluoroquinolones (ciprofloxacin) are … agents and they are extremely active against … but less active against anaerobic bacteria like …

Answer 25

bactericidal

A.a.

P.g.

Question 26

fluoroquinolones (ciprofloxacin) are excellent for … bacteria

Answer 26

facultative

Question 27

fluoroquinolones (ciprofloxacin) can penetrate … and … and can kill invasive bacteria

Answer 27

epithelial cells

phagocytes

Question 28

clindamycin has potent …. activity against ….

but is less effective against …. like ….

Answer 28

bacteriostatic

strict anaerobes

facultative pathogens

a.a.

Question 29

…. is usually used as an alternative antimicrobial agent in penicillin-allergic patients

Answer 29

clindamycin

Question 30

clindamycin penetrates … and can occasionally induce …

Answer 30

bone

ulcerative colitis

Question 31

macrolides are … and ….

Answer 31

azithromycin and clarithromycin (z-pack)

Question 32

are macrolides expensive?

Answer 32

yes

Question 33

macrolides can reach …

Answer 33

high concentrations in tissue

Question 34

macrolides have good activity against … , … and …

Answer 34

a.a.
p.g.
many other gram negative anaerobes

Question 35

macrolides penetrates …. and kills invasive bacteria and can also be taken up by

Answer 35

epithelial cells

PMNs and fibroblasts

Question 36

macrolides produce … effects

Answer 36

anti-inflammatory

Question 37

common features of tetracyclines, ciprofloxacin, azithromycin, clarithromycin

Answer 37

levels in GCF are higher than in blood

actively accumulated by PMNs, fibroblasts and epithelial cells

Question 38

empirical regimen for aggressive periodontitis or severe chronic periodontitis

Answer 38

amoxicillin (500 mg TID) combined with metronidazole (250 mg TID) for 8 days

Question 39

alternative regimens for PCN-allergic patients

Answer 39

azithromycin (500mg starting dose then 250mg/day for 4 days)

metronidazole (500mg TID for 7 days)

Question 40

the magnitude of improvement associated with the use of arestin is …

Answer 40

0.3mm

Question 41

possible indications for systemic antibiotics

Answer 41

aggressive periodontitis

periodontal abscess (if severe)

NUG (if severe)

Question 42

Erythromycin, clindamycin, tetracycline all inhibit

Answer 42

protein synthesis
(erythromycin and clindamycin 50S)
(tetracycline 30S)

Question 43

azithromycin induces a decrease in GCF …. and … in healthy subjects

Answer 43

IL8

TNF

Question 44

molecular tests require … not …

Answer 44

DNA

live bacteria