Antibiotics

Question 1

What is the fundamental principle of antibiotic use in oral surgery?

Answer 1

Antibiotics are adjuncts to surgical management and do not replace incision and drainage

Question 2

When are antibiotics indicated in oral surgery?

Answer 2

• When there is systemic involvement or risk of spread:
• fever

Question 3

Which oral surgery conditions do NOT routinely require antibiotics?

Answer 3

• Pain alone;
• chronic periapical lesions without spread;
• dry socket;
• localized abscess that is adequately drained in a healthy patient;
• mild pericoronitis.

Question 4

What organisms are targeted by empiric antibiotics in odontogenic infections?

Answer 4

Primarily gram-positive cocci (streptococci) and anaerobic bacteria.

Question 5

What is the first-line management of an odontogenic abscess?

Answer 5

Source control via incision and drainage

Question 6

What is the safest general duration principle for dental antibiotic courses?

Answer 6

• Use the shortest effective course w/ early review;
• commonly 5–7 days depending on agent and response.

Question 7

What is the class and mechanism of amoxicillin?

Answer 7

• Aminopenicillin (β-lactam);
• inhibits bacterial cell wall synthesis by binding penicillin-binding proteins.

Question 8

What is a common adult oral-surgery dose of amoxicillin?

Answer 8

500 mg every 8 hours.

Question 9

What is the class and mechanism of amoxicillin–clavulanate?

Answer 9

• β-lactam plus β-lactamase inhibitor;
• clavulanate protects amoxicillin from enzymatic degradation.

Question 10

What are common adult oral-surgery dosing patterns for amoxicillin–clavulanate?

Answer 10

• 625 mg every 8 hours or
• 1000 mg every 12 hours.

Question 11

What is the class and mechanism of metronidazole?

Answer 11

• Nitroimidazole;
• causes DNA damage in anaerobic bacteria leading to cell death.

Question 12

What is a common adult oral-surgery dose of metronidazole?

Answer 12

250–500 mg every 8 hours.

Question 13

What is the class and mechanism of clindamycin?

Answer 13

• Lincosamide;
• Inhibits protein synthesis by binding to the 50S ribosomal subunit.

Question 14

What is a common adult oral-surgery dose of clindamycin?

Answer 14

150–450 mg every 6 hours.

Question 15

What is the major adverse risk associated with clindamycin?

Answer 15

High risk of antibiotic-associated diarrhea and Clostridioides difficile colitis.

Question 16

What is the class and mechanism of macrolides?,

Answer 16

• (e.g. azithromycin, clarithromycin)
• inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit and blocking translocation

Question 17

What is a common adult dosing regimen for azithromycin in dental infections?

Answer 17

• 500 mg on day 1 followed by 250 mg once daily on days 2–5
• OR 500 mg once daily for 5 days.

Question 18

What is a common adult dosing regimen for clarithromycin in dental infections?

Answer 18

• 250–500 mg every 12 hours for approximately 7 days.

Question 19

What is the class and mechanism of fluoroquinolones?

Answer 19

• Fluoroquinolones inhibit DNA gyrase and topoisomerase IV

Question 20

Why are fluoroquinolones not first-line antibiotics in dentistry?

Answer 20

• They have significant adverse effects
• are broader-spectrum than needed for typical odontogenic infections.

Question 21

What is the typical adult dose of moxifloxacin when used in dental infections?

Answer 21

400 mg once daily.

Question 22

What are key contraindications to moxifloxacin?

Answer 22

Pregnancy and patients under 18 years of age.

Question 23

What is the role of antibiotics in routine uncomplicated tooth extraction?

Answer 23

• Antibiotics are not routinely indicated;
• aseptic technique
• local measures are sufficient.

Question 24

When may antibiotics be considered after oral surgery?

Answer 24

When signs of infection develop such as fever

Question 25

Does diabetes alone mandate antibiotics after oral surgery?

Answer 25

No; diabetes alone is not an automatic indication for antibiotics.

Question 26

How does diabetes influence antibiotic decision-making in oral surgery?

Answer 26

* It **lowers the threshold** to prescribe antibiotics=> * if **infection** is **present** and necessitates closer follow-up.

Question 27

Does diabetes require altered antibiotic doses or durations?

Answer 27

* **No fixed diabetes-specific doses** or durations; * **standard** adult dosing is used w/ **closer monitoring.**

Question 28

When are antibiotics more likely to be required after oral surgery in diabetic patients?

Answer 28

Poor glycaemic control

Question 29

What is the recommended approach to antibiotic use in immunocompromised patients?

Answer 29

Lower threshold for prescribing

Question 30

How should penicillin allergy influence antibiotic choice?

Answer 30

* **Avoid β-lactams** in true immediate allergy * use **macrolides** or **clindamycin** instead.

Question 31

What caution applies to cephalosporin use in penicillin-allergic patients?

Answer 31

* Avoid in patients with a history of **anaphylaxis** * or immediate hypersensitivity to **penicillin.**

Question 32

Which oral surgery infections require urgent referral rather than outpatient antibiotics alone?

Answer 32

Deep fascial space infections

Question 33

What is the key principle for preventing surgical site infection in oral surgery?

Answer 33

Meticulous asepsis

Question 34

What are the classic signs of surgical site infection (SSI) after oral surgery?

Answer 34

Fever (usually 3–5 days post-op); increasing pain; erythema; swelling; wound dehiscence; purulent discharge; foul smell.

Question 35

When should post-operative oral surgery infection be suspected?

Answer 35

* When **pain** and **swelling** **worsen** after **initial improvement** * or **systemic signs appear** several days post-operatively.

Question 36

What is the first step in managing a post-operative oral surgery infection?

Answer 36

* **Drain** any purulence and establish **source control**=> * before or alongside antibiotics.

Question 37

When should microbiological culture and sensitivity be taken in oral surgery infections?

Answer 37

* In **rapidly** progressive infections; * **recurrent** infections; * **post-operative** infections; * **immunocompromised** patients; * **failure** of first-line antibiotics.

Question 38

Which odontogenic infections commonly require antibiotic therapy?

Answer 38

* **Spreading** cellulitis; * **phlegmon** * **deep fascial space** infection; * **osteomyelitis** * **severe** pericoronitis w/ **systemic signs.**

Question 39

What defines a phlegmon in oral surgery?

Answer 39

* A **diffuse spreading, acute suppurative** inflammation of soft tissues=> * **not well localised** and has **no clear** abscess cavity.

Question 40

What is the antibiotic role in pericoronitis?

Answer 40

Antibiotics are indicated only if there is **trismus**

Question 41

What is the antibiotic role in alveolar osteitis (dry socket)?

Answer 41

* Antibiotics are **NOT** indicated * management is **local irrigation**

Question 42

What is the antibiotic role in chronic apical periodontitis?

Answer 42

* Antibiotics are **not indicated**=> * unless **acute exacerbation** w/ **systemic** spread.

Question 43

What is the antibiotic role in acute apical abscess?

Answer 43

* Antibiotics only if **systemic signs** or **spread** are present; * **local drainage** is primary.

Question 44

What is the antibiotic role in osteomyelitis of the jaws?

Answer 44

* Antibiotics indicated and usually **combined w/ surgical debridement** * treatment duration **longer** and **specialist-led.**

Question 45

What is the antibiotic role in necrotizing periodontal diseases (ANUG/NPD)?

Answer 45

Antibiotics may be indicated when systemic symptoms are present or disease is severe.

Question 46

What is the role of antibiotics in routine third molar surgery?

Answer 46

Routine post-operative antibiotics are not recommended in healthy patients.

Question 47

When may antibiotic prophylaxis be considered in oral surgery?

Answer 47

In **high-risk** procedures or patients where **infection risk** outweighs resistance risk.

Question 48

What is the general principle of antibiotic prophylaxis timing in oral surgery?

Answer 48

* Administer **shortly before procedure**=> * ensure **adequate tissue levels** at incision time.

Question 49

What is the general principle of antibiotic prophylaxis duration?

Answer 49

* **Single pre-operative dose** is usually sufficient; * prolonged courses are **discouraged.**

Question 50

Does diabetes alone justify antibiotic prophylaxis in oral surgery?

Answer 50

No; diabetes alone is not an indication for prophylactic antibiotics.

Question 51

How does diabetes affect post-operative infection risk?

Answer 51

Diabetes increases risk of **delayed healing** and **infection**

Question 52

How should oral surgery infections be managed in diabetic patients?

Answer 52

Use **standard** adult antibiotic doses when indicated

Question 53

Is there a diabetes-specific antibiotic dose or duration after oral surgery?

Answer 53

No fixed diabetes-specific dosing; standard regimens are used with closer monitoring.

Question 54

When are antibiotics more likely to be needed after oral surgery in diabetics?

Answer 54

Poor glycaemic control

Question 55

What is the key antibiotic consideration in immunocompromised oral surgery patients?

Answer 55

* **Lower threshold** to prescribe antibiotics * **earlier escalation** if infection develops.

Question 56

Why are bactericidal antibiotics preferred in immunocompromised patients?

Answer 56

They kill bacteria directly rather than relying on host immune response.

Question 57

What is the antibiotic approach in pregnancy for oral surgery infections?

Answer 57

* **Prefer penicillins** when indicated; * **avoid** **fluoroquinolones** and **tetracyclines.**

Question 58

Which antibiotics are contraindicated in pregnancy in oral surgery?

Answer 58

Fluoroquinolones and tetracyclines.

Question 59

What antibiotic considerations apply in renal impairment?

Answer 59

* **Dose adjustment** may be required depending on renal function; * **consult** product characteristics.

Question 60

What antibiotic considerations apply in hepatic impairment?

Answer 60

* Use **caution** and consider **dose** **adjustment**/avoidance for antibiotics w/ significant **hepatic** **metabolism** (especially macrolides and metronidazole); * monitor for **toxicity** and follow product characteristics

Question 61

What interaction is important between metronidazole and anticoagulants?

Answer 61

* Metronidazole can **increase INR** and **bleeding risk** in patients on **warfarin**.

Question 62

Why should unnecessary antibiotic combinations be avoided?

Answer 62

* They increase **adverse effects** and **antimicrobial resistance** w/out improving outcomes.

Question 63

When is combination antibiotic therapy justified in oral surgery?

Answer 63

* **Severe spreading** infections * or when **anaerobic coverage** is required.

Question 64

What is the escalation principle if no improvement after 48–72 hours of antibiotics?

Answer 64

Reassess diagnosis and source control

Question 65

Which oral surgery infections require urgent hospital referral?

Answer 65

Deep fascial space infection

Question 66

What is the overarching goal of antibiotic stewardship in oral surgery?

Answer 66

To effectively treat infection while minimizing resistance