What term describes the ability of cariogenic bacteria to thrive under acidic conditions, leading to dominance of plaque by these bacteria?

• A. Aciduricity
• B. Acidogenicity
• C. Alkalinogenicity
• D. Cariogenic potential

Answer: (A)

Aciduricity is the ability to survive and even multiply in acidic environments. In dental plaque, frequent sugar intake lowers the local pH as bacteria produce acids. Those that are acid-tolerant—aciduric—can continue to grow under these harsh conditions, so they become the dominant bacteria in the biofilm. This selective survival at low pH helps sustain a plaque community rich in aciduric organisms, driving ongoing demineralization and caries progression.

Acidogenicity, by contrast, describes the capacity of bacteria to produce acid from fermentable carbohydrates, which contributes to caries but doesn’t specifically capture their resilience to acidic conditions. Alkalinogenicity would mean raising the pH, the opposite of what’s happening in cariogenic situations. Cariogenic potential is a broader term referring to the overall ability to cause caries, not specifically the acid tolerance aspect.