Fluoride Applications Practice Questions
20 free Fluoride Applications practice questions for the CDA. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
What is the primary benefit of fluoride in preventive dentistry?
- A To whiten the teeth
- B To strengthen enamel and prevent demineralisation
- C To remove plaque from the tooth surface
- D To decrease tooth sensitivity immediately
Correct answer: To strengthen enamel and prevent demineralisation
Fluoride enhances enamel's resistance to acid attacks by promoting remineralisation. This helps prevent caries development.
Which professional fluoride application is most commonly used for high-risk pediatric patients?
- A Fluoride varnish
- B Water fluoridation
- C Over-the-counter fluoride toothpaste
- D Fluoride mouthrinse only
Correct answer: Fluoride varnish
Fluoride varnish adheres well to tooth surfaces and is safe and effective for children. It provides long-lasting fluoride exposure.
What concentration of fluoride is typically found in over-the-counter fluoride toothpaste?
- A 100 ppm
- B 1,000–1,500 ppm
- C 5,000 ppm
- D 10,000 ppm
Correct answer: 1,000–1,500 ppm
Most OTC toothpastes contain 1,000–1,500 ppm fluoride. This concentration effectively reduces caries risk for the general population.
Which type of fluoride treatment is recommended for patients with xerostomia?
- A Acidulated phosphate fluoride (APF) gel
- B Silver diamine fluoride
- C Neutral sodium fluoride
- D No fluoride therapy
Correct answer: Neutral sodium fluoride
Neutral sodium fluoride is gentle and safe for patients with dry mouth. APF can damage restorations, making NaF preferred.
Which fluoride compound is known for its ability to penetrate enamel quickly?
- A Stannous fluoride
- B Acidulated phosphate fluoride
- C Calcium fluoride
- D Potassium fluoride
Correct answer: Acidulated phosphate fluoride
APF is acidic, allowing it to rapidly penetrate enamel. This enhances fluoride uptake during professional applications.
How soon after a fluoride varnish application should a patient avoid brushing?
- A Immediately after treatment
- B For at least 4–6 hours
- C For 24 hours
- D For 2 days
Correct answer: For at least 4–6 hours
Patients should avoid brushing for several hours to allow the varnish to remain on the teeth. This prolongs fluoride contact.
What is the main advantage of fluoride varnish compared with gel trays?
- A It is less expensive
- B It adheres well and reduces the risk of ingestion
- C It whitens teeth more effectively
- D It requires no drying of the teeth
Correct answer: It adheres well and reduces the risk of ingestion
Varnish stays on the teeth, limiting ingestion risk, especially for children. It also provides sustained fluoride release.
Which fluoride treatment is contraindicated on patients with porcelain or composite restorations?
- A Silver diamine fluoride
- B Neutral sodium fluoride
- C Acidulated phosphate fluoride
- D Fluoride varnish
Correct answer: Acidulated phosphate fluoride
APF can etch and damage porcelain and composite surfaces. Neutral sodium fluoride is the safer alternative.
What is the recommended professional fluoride application frequency for high-caries-risk patients?
- A Every 12 months
- B Every 6 months
- C Every 3–6 months
- D Only once in childhood
Correct answer: Every 3–6 months
High-risk patients benefit from more frequent fluoride contact. Professional applications every 3–6 months help prevent caries.
Which fluoride source provides continuous low-level exposure to a community?
- A Fluoride varnish
- B Water fluoridation
- C Fluoride mouthrinse
- D Fluoride tablets
Correct answer: Water fluoridation
Community water fluoridation delivers ongoing fluoride exposure. It is considered one of the most effective public health measures.
What is the mechanism by which fluoride prevents caries?
- A It kills all oral bacteria
- B It blocks saliva flow
- C It enhances remineralisation and inhibits demineralisation
- D It seals pits and fissures directly
Correct answer: It enhances remineralisation and inhibits demineralisation
Fluoride strengthens enamel crystals and slows down demineralisation. It also supports rebuilding early white-spot lesions.
Which patient group benefits most from prescription-strength 5,000 ppm fluoride toothpaste?
- A Low-risk adults
- B Toddlers
- C High-caries-risk teens and adults
- D Patients undergoing orthodontic band removal
Correct answer: High-caries-risk teens and adults
High-risk patients require higher fluoride concentrations for remineralisation. Prescription pastes offer enhanced protection.
What is a common side effect of excessive fluoride intake in children?
- A Dental erosion
- B Dental fluorosis
- C Gingival recession
- D Pulp necrosis
Correct answer: Dental fluorosis
Excess fluoride during tooth formation can lead to fluorosis. It affects enamel appearance but not tooth function.
Which product contains stannous fluoride?
- A Most over-the-counter whitening strips
- B Some anti-gingivitis toothpastes
- C Alginate dental impression materials
- D Topical anesthetic numbing gels
Correct answer: Some anti-gingivitis toothpastes
Stannous fluoride offers antimicrobial benefits. It is commonly found in anti-gingivitis and anti-sensitivity toothpastes.
Why should patients avoid eating or drinking for 30 minutes after using fluoride gel trays?
- A To prevent unsightly surface staining of the teeth
- B To reduce the amount of fluoride absorbed systemically
- C To allow fluoride uptake into enamel
- D To avoid irritation of the soft tissues
Correct answer: To allow fluoride uptake into enamel
Waiting allows fluoride to remain in contact with teeth. This enhances its ability to strengthen enamel.
Which fluoride treatment is most effective for arresting early root caries?
- A Fluoride mouthrinse
- B Silver diamine fluoride
- C Fluoride foam
- D Low-dose fluoride toothpaste
Correct answer: Silver diamine fluoride
Silver diamine fluoride arrests root caries by killing bacteria and hardening softened dentin. It is highly effective for older adults.
Which type of patient should use fluoride mouthrinse regularly?
- A Patients with orthodontic appliances
- B Patients wearing full or partial dentures
- C Patients with no natural teeth
- D Patients with severe tooth mobility
Correct answer: Patients with orthodontic appliances
Orthodontic appliances trap plaque and increase caries risk. Fluoride rinses offer additional protection.
What is the main benefit of silver diamine fluoride (SDF)?
- A It whitens enamel
- B It arrests active carious lesions
- C It desensitises nerve endings immediately
- D It seals pits and fissures
Correct answer: It arrests active carious lesions
SDF effectively halts caries progression. It is especially valuable when traditional restorative treatment is not possible.
Which professional fluoride form is best for patients with strong gag reflexes?
- A Gel in trays
- B Fluoride rinse
- C Foam trays
- D Fluoride varnish
Correct answer: Fluoride varnish
Varnish requires no tray and only a small amount is used. This makes it ideal for patients prone to gagging.
Which factor increases the risk of fluoride overdose?
- A Receiving routine yearly fluoride varnish applications
- B Swallowing large amounts of toothpaste
- C Drinking optimally fluoridated tap water
- D Using a soft-bristled manual toothbrush
Correct answer: Swallowing large amounts of toothpaste
Children who swallow toothpaste may ingest excessive fluoride. Proper supervision helps prevent accidental overuse.