Demineralization of cementum occurs at what pH range?

• A. 5.0-5.5
• B. 4.0-4.5
• C. 6-6.7
• D. 7-7.5

Answer: (C)

Demineralization happens when the environment becomes acidic enough to dissolve the minerals in tooth tissues. Cementum is less mineralized than enamel and has a structure more similar to bone, with minerals that are more readily dissolved under acid. This makes its threshold for dissolution higher, so it begins to demineralize at a pH around 6 to 6.7. Below that range, minerals start dissolving; above it, the tissue remains largely mineralized. The other ranges are either more acidic (where enamel would already be affected) or near neutral (where demineralization is minimal), so the pH 6–6.7 window best fits when cementum starts to demineralize.