Role of Antibiotics

Question 1

What are some potential indications for systemic antibiotics in perio disease?

Answer 1

1. Aggressive periodontitis
2. Severe perio abscess
3. Severe NUG

Question 2

Which bacteria in the subgingival biofilm indicate the use of antibiotics?

Answer 2

P. gingivalis and A.a.

Question 3

T/F: Antibiotics can be useful because deep pockets can be hard to reach, and some bacteria enter the soft tissue.

Answer 3

True

Question 4

T/F: Antibiotics can be effective without SRP.

Answer 4

False

Biofilm is resistant to antibiotics if not disrupted by SRP

Question 5

T/F: Bacteria that invade into host tissue are removed with SRP.

Answer 5

False

This is where antibiotics can help

Question 6

What is the difference between a bactericidal agent and a bacteriostatic agent?

Answer 6

Bactericidal: kills bacteria (homiCIDE, suiCIDE)

Bacteriostatic: slows bacterial growth

Question 7

T/F: Broad spectrum antibiotics are preferred for treating periodontitis.

Answer 7

False

Narrow-spectrum are preferred because they spare gut bacteria

Question 8

T/F: Penicillins kill bacteria.

Answer 8

True

But not effective against all A. a. strains

Question 9

Penicillins are inactivated by _________.

Answer 9

Beta-lactamases

Question 10

T/F: Penicillins are very good at penetrating epithelium.

Answer 10

False

Effective in gingival fluid

Question 11

__________ is a penicillin with broad spectrum, enhanced tissue penetration, and is effective against gram negative bacteria.

Answer 11

Amoxicillin

Question 12

_________ is amoxicillin with a beta-lactamase inhibitor.

Answer 12

Augmentin

Question 13

Which part of the bacteria do penicillins act on?

Answer 13

Cell wall

Question 14

_________ is a narrow-spectrum bactericidal agent that is active against strict anaerobes.

Answer 14

Metronidazole

Not as active against A. a.

Question 15

T/F: Tetracyclines are bacteriostatic, broad-spectrum antibiotics.

Answer 15

True

Question 16

Tetracyclines inhibit ________ which mediates collagen breakdown in periodontitis.

Answer 16

collagenase

Question 17

What makes tetracyclines a strong candidate for periodontal antibiotic therapy?

Answer 17

1. Inhibits collagenase

2. Occumulated by epithelial cells, gingival fibroblasts, and PMNs

Question 18

How does tetracycline act on a bacterial cell?

Answer 18

Inhibits protein synthesis (30S inhibitor)

Question 19

Minocycline and doxycycline are both examples of _________.

Answer 19

tetracyclines

Question 20

T/F: Fluorquinolones are bacteriostatic.

Answer 20

False

Bacteridical

Question 21

When would you prescribe a patient with ciprofloxacin?

Answer 21

It is a fluoroquinolone so it is very active against A. a.

So in a patient with aggressive periodontitis it would be very effective

Question 22

T/F: Ciprofloxacin (fluoroquinolone) can penetrate epithelial cells and phagocytes and can kill invasive bacteria.

Answer 22

True

Question 23

How does clindamycin act on a bacterial cell?

Answer 23

Inhibits protein synthesis (50S inhibitor)

Question 24

T/F: Clindamycin would be a good antibiotic for a patient with aggressive periodontitis.

Answer 24

False

Not effective against A. a.

Question 25

What is a negative side effect specific to clindamycin?

Answer 25

Can induce ulcerative colitis

Question 26

T/F: Clindamycin is often used in patients who are allergic to penicillin.

Answer 26

True

Question 27

Azithromycin and clarithromycin are both ________.

Answer 27

Macrolides

Question 28

Macrolides are ____ inhibitors.

Answer 28

50S

Question 29

What are the advantages of macrolides?

Answer 29

1. Good activity against A. a., P. g., and other gram-negative anaerobes 2. Penetrates epithelial tissues 3. Bactericidal 4. Anti-inflammatory 5. Simple regimen

Question 30

What is the major downside of prescribing macrolides?

Answer 30

Expensive

Question 31

T/F: Macrolides like clarithromycin reach higher levels in inflamed gingiva than in healthy gingiva.

Answer 31

True

Question 32

What are some common features of tetracyclines, ciprofloxacin, azithromycin, and clarithromycin?

Answer 32

1. Levels in gingival crevicular fluid are often higher than levels in blood 2. Actively accumulated by PMNs, fibroblasts, and oral epithelium 3. Can kill invasive bacteria

Question 33

Amoxicillin and metronidazole are both ________ agents. But doxycycline and azithromycin are both ________ agents.

Answer 33

bactericidal; bacteriostatic

Question 34

T/F: Molecular tests for specific bacteria are more sensitive than culture methods.

Answer 34

True

Question 35

T/F: Molecular tests for specific bacteria require live bacterial cells.

Answer 35

False Just DNA

Question 36

What are the major downsides of bacterial culturing?

Answer 36

1. Logistics (cost, transport, availability) 2. Not very sensitive 3. Difficult to grow spirochetes

Question 37

When would you want to utilize a microbiological test?

Answer 37

After a poor response to initial therapy

Question 38

What is the preferred regimen for aggressive periodontitis or severe chronic periodontitis?

Answer 38

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

Question 39

What are two alternative regimens for patients with penicllin allergies?

Answer 39

1. Azithromycin (500mg starting dose, then 250mg/day for 4 days) 2. Metronidazole (500mg TID for 7 days)

Question 40

Antibiotic therapy is most beneficial for patients .....

Answer 40

with deep pockets who are unresponsive to initial treatment, or who have aggressive periodontitis

Question 41

T/F: Antibiotics are just as effective on patients who undergo surgical therapy as those who undergo non-surgical therapy.

Answer 41

False Benefits are greater in patients with non-surgical therapy

Question 42

What are the major limitations of antibiotics in periodontics?

Answer 42

1. Not effective without SRP | 2. Undesirable side effects

Question 43

What are some general side effects that can be associated with systemic antibiotics?

Answer 43

1. Induce resistance 2. Microbial overgrowth 3. Hypersesisitivity/toxicity

Question 44

Dental staining is a side effect often seen with _______.

Answer 44

tetracyclines

Question 45

Altered taste is a common side effect seen with ______.

Answer 45

metronidazole

Question 46

Cholestatic jaundice and cardiac arrhythmia are rare side effects associated with _________.

Answer 46

azithromycin

Question 47

T/F: Dentists can help prevent inducing antibiotic resistance by prescribing broad-spectrum antibiotics and telling patients to only use them until their symptoms are gone.

Answer 47

False Use narrow-spectrum and have patient take the full dosage

Question 48

What are the shortcomings of local delivery of antibiotics?

Answer 48

1. Less effective at eradicating invasive bacteria 2. Recurrent infection from other parts of the mouth 3. Time consuming and not cost-effective

Question 49

What is the current application for local antibiotic delivery?

Answer 49

Treatment of localized recurrent periodontitis in cases that are otherwise stable