Which statement about coronal caries dissolution with respect to pH is true?

Which statement about coronal caries dissolution with respect to pH is true?

• A. Acid dissolution is slower under low pH
• B. Acid dissolution is faster under low pH
• C. Acid dissolution is slower under high pH
• D. Acid dissolution is faster under high pH

Answer: (A)

The main idea is that acid conditions accelerate enamel dissolution. When the surface pH drops and becomes more acidic, hydroxyapatite in enamel becomes more soluble, so demineralization occurs faster. The critical pH for enamel dissolution is around 5.5; below this value, mineral loss from the enamel is enhanced, while above it, dissolution slows and remineralization can keep up with or exceed loss. So the statement that acid dissolution is faster under low pH reflects how cariogenic acids drive coronal caries. If the environment were less acidic (higher pH), dissolution would occur more slowly, not faster.

The main idea is that acid conditions accelerate enamel dissolution. When the surface pH drops and becomes more acidic, hydroxyapatite in enamel becomes more soluble, so demineralization occurs faster. The critical pH for enamel dissolution is around 5.5; below this value, mineral loss from the enamel is enhanced, while above it, dissolution slows and remineralization can keep up with or exceed loss. So the statement that acid dissolution is faster under low pH reflects how cariogenic acids drive coronal caries. If the environment were less acidic (higher pH), dissolution would occur more slowly, not faster.