What in corn meal or corn flour-based foods is a potential source of a cariogenic food substance?

• A. Galactose
• B. Sucrose
• C. Lactose
• D. Mannose

Answer: (B)

Sugars that drive dental caries are those that plaque bacteria can readily metabolize to acids, and some sugars also help bacteria stick to teeth. Sucrose is particularly problematic because oral bacteria like Streptococcus mutans can use it not only for rapid acid production but also to synthesize extracellular polysaccharides (dextran) that make plaque more sticky and persistent. This combination—easy fermentation to acid and enhanced plaque formation—makes sucrose more cariogenic than other common sugars.

In corn meal or corn flour–based foods, the risk comes from added sucrose or other sweeteners, since corn itself is mainly starch. If a corn product contains sucrose, it provides the fermentable substrate that can fuel tooth demineralization. The other sugars listed—galactose, lactose, and mannose—are not as readily used by plaque bacteria to produce acids or to form sticky plaque, and they are less typically present in corn-based foods in cariogenic amounts, so they are less associated with caries risk.