Which sugar is cariogenic in corn meal-based foods?

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

Answer: (B)

Sugars that drive tooth decay are those that oral bacteria can rapidly ferment to acids and that help plaque stick to teeth. Sucrose stands out because it is readily utilized by plaque bacteria like Streptococcus mutans to produce lactic acid, and it has a unique ability to be converted into extracellular glucans (sticky polysaccharides) that help bacteria adhere to and retain themselves in the tooth surface. This combination—fast acid production and enhanced plaque formation—makes sucrose the most cariogenic among common dietary sugars, especially in foods that are starchy yet can become sticky, like corn meal-based products.

Lactose, galactose, and mannose are less cariogenic in typical dietary scenarios because they are less readily fermented by the key cariogenic bacteria and are not as efficient at promoting sticky plaque formation.