Which tissue has greater buffering capacity against acids?

• A. Enamel
• B. Cementum
• C. Dentin
• D. Pulp

Answer: (C)

Buffering capacity is the tissue’s ability to neutralize acids by providing ions that react with hydrogen ions and help maintain a stable pH. Enamel is highly mineralized with very little water or organic matrix, so it has virtually no internal reservoir to buffer acids and tends to demineralize when exposed to acid. Cementum is also mineral-rich with limited buffering components, so its ability to counteract acid is modest. In contrast, dentin contains a substantial organic matrix and a network of dentinal tubules filled with dentinal fluid that carries water and buffering ions such as bicarbonate and phosphate. These ions can react with acids as they diffuse through the tubules, providing a meaningful buffering effect and helping to stabilize pH inside the tooth. While pulp has its own buffering capacity via vascular and cellular mechanisms, the structural buffering reservoir present in dentin makes it the tissue with greater inherent buffering against acids.