Step 1: What is an anticaries agent?
Dental caries (tooth decay) is caused by acid produced by oral bacteria acting on tooth enamel (hydroxyapatite). An anticaries agent prevents this demineralization or promotes remineralization of enamel.
Step 2: How does fluoride protect teeth?
Fluoride ions (F-) replace hydroxyl groups (OH-) in hydroxyapatite, converting it to fluorapatite. Fluorapatite is harder, less soluble in acid, and much more resistant to bacterial acids. Additionally, fluoride inhibits bacterial enzymes involved in acid production.
Step 3: Why Sodium Fluoride specifically?
Sodium Fluoride (NaF) is the most commonly used inorganic fluoride source in dentistry. It is found in toothpastes, mouthwashes, and professional fluoride treatments. It delivers the fluoride ion efficiently and is safe at recommended concentrations.
Step 4: Rule out the distractors.
Calcium Carbonate (Option 1): Used as a polishing/abrasive agent in toothpaste; does NOT have anticaries activity. Zinc Chloride (Option 3): Used as an astringent and antiseptic, NOT anticaries. Sodium Chloride (Option 4): Common salt with no anticaries property.
Step 5: Confirm the answer.
Sodium Fluoride is the inorganic compound specifically used as an anticaries agent, well-established in pharmaceutical and dental sciences.
Answer: Option (2) — Sodium Fluoride