Which of the following is not a major risk factor for caries development?

• A. Adequate fluoride exposure
• B. Frequent sugar exposure
• C. Reduced saliva flow
• D. Poor oral hygiene

Answer: (A)

Adequate fluoride exposure protects against caries by strengthening enamel and slowing demineralization. Fluoride promotes remineralization, forms more acid-resistant fluorapatite, and can inhibit bacterial acid production, making the mouth less prone to decay. That protective effect means it is not a major risk factor for caries. In contrast, frequent sugar exposure provides fermentable carbohydrates that bacteria convert to acids, lowering pH and dissolving enamel; reduced saliva flow lowers buffering and clearance of acids and sugar, increasing acid exposure; and poor oral hygiene allows plaque buildup with more acid-producing bacteria. So the protective fluoride factor is the one that does not contribute as a risk.