Which statement correctly describes acid dissolution in root caries according to the material?

• A. Slower under higher pH
• B. Faster under higher pH
• C. Slower under lower pH
• D. Faster under lower pH

Answer: (B)

Acid dissolution of root caries increases as the environment becomes more acidic because hydrogen ions at lower pH actively disrupt the mineral components of dentin and cementum. Root surfaces are more vulnerable than enamel due to their lower mineral density and higher organic content, so when plaque acids lower the pH, demineralization proceeds more rapidly. As pH rises, the driving force for mineral loss diminishes and remineralization can occur, slowing or halting dissolution. Therefore, the statement that dissolution is faster under lower pH correctly reflects how acid attack drives root caries progression. The opposing idea would contradict the basic chemistry of demineralization.