Preventive Dentistry and Caries Risk Assessment
What the exam tests
Preventive questions are risk-based, not ritual-based: who needs fluoride varnish, sealants, or a 3-month recall, and what evidence supports each decision.
Core rules
- First dental visit by the first tooth or age 1; establish a dental home.
- Caries risk factors: previous caries or white spots, caregiver mutans transmission, frequent sugar exposure, inadequate fluoride, enamel hypoplasia, dry mouth, special health care needs. Protective factors: fluoride, saliva, xylitol, sealants.
- Toothpaste: smear (rice grain) of 1000 ppm from first tooth to age 3; pea-size at 3-6 years; supervise and spit, do not rinse.
- Fluoride varnish 5% NaF (22,600 ppm) every 3-6 months for high-risk children; APF 1.23% gel for 4 minutes; supplements only if water fluoride is below 0.3 ppm.
- Resin-based sealants on pits and fissures of permanent molars; glass ionomer where isolation is poor; recheck at recall.
- Silver diamine fluoride 38% arrests active dentinal caries in primary teeth, but stains and does not replace pulpal diagnosis.
Worked example
A 3-year-old has two cavitated maxillary incisors, a nighttime bottle, and a sibling with caries. Reasoning: high caries risk. Stop the bottle, apply fluoride varnish now, use a 1000 ppm smear twice daily, counsel the caregiver, restore or extract the incisors, use SDF if restoration is impossible, and recall at 3 months. Sealants are not yet indicated because no permanent molars have erupted.
Traps
Prescribing supplements without knowing water fluoride; telling parents to rinse after brushing; sealing over active caries; applying SDF to a tooth with a sinus tract.