Dental Dental Pharmacology 2 — Questions and Answers
Question 1: Which drug classification does nitrous oxide (N₂O) fall under in dentistry?
- General anesthetic
- Anxiolytic/minimal sedation agent (Correct answer)
- Local anesthetic
- Analgesic only
Correct answer: Anxiolytic/minimal sedation agent
Nitrous oxide combined with oxygen is classified as a minimal sedation/anxiolytic agent in dentistry that reduces anxiety and provides mild analgesia while maintaining consciousness.
Question 2: Amoxicillin is the antibiotic of choice for endocarditis prophylaxis before dental procedures. What is the standard adult prophylactic dose?
- 500 mg 1 hour before
- 1 g 1 hour before
- 2 g 30–60 minutes before (Correct answer)
- 500 mg twice daily for 7 days
Correct answer: 2 g 30–60 minutes before
The AHA/ADA recommend a single oral dose of amoxicillin 2 g administered 30–60 minutes before the dental procedure for infective endocarditis prophylaxis.
Question 3: Which topical anesthetic agent is commonly applied before intraoral injections to reduce needle insertion pain?
- Prilocaine 4%
- Benzocaine 20% (Correct answer)
- Bupivacaine 0.5%
- Mepivacaine 3%
Correct answer: Benzocaine 20%
Benzocaine 20% gel or liquid is the most commonly used topical dental anesthetic applied to mucous membranes before injections to minimize discomfort.
Question 4: Fluoride varnish applied professionally to teeth helps prevent caries primarily through which mechanism?
- Killing Streptococcus mutans bacteria directly
- Promoting remineralization and inhibiting demineralization of enamel (Correct answer)
- Physically sealing pit-and-fissure surfaces
- Reducing salivary pH
Correct answer: Promoting remineralization and inhibiting demineralization of enamel
Fluoride varnish provides a high-concentration fluoride reservoir that is slowly released, promoting remineralization of early enamel lesions and inhibiting bacterial acid production.
Question 5: A patient taking warfarin (anticoagulant) requires a tooth extraction. What INR level is generally considered safe to proceed with routine dental extractions?
- INR below 1.0
- INR 1.5–2.0
- INR up to 3.5 (Correct answer)
- INR above 4.0
Correct answer: INR up to 3.5
Most dental literature supports proceeding with routine extractions when a patient's INR is ≤3.5, as local hemostatic measures are typically sufficient to control bleeding.
Question 6: Xerostomia (dry mouth) as a side effect of medications increases the patient's risk for which oral condition?
- Pericoronitis
- Rampant dental caries (Correct answer)
- Acute necrotizing ulcerative gingivitis
- Ludwig's angina
Correct answer: Rampant dental caries
Saliva provides critical buffering and antibacterial functions; its reduction (xerostomia) dramatically increases the risk of rampant caries due to uncontrolled bacterial acid accumulation.
Dental Dental Pharmacology 2
Which drug classification does nitrous oxide (N₂O) fall under in dentistry?