Bonding to enamel or dentin is stronger.

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

Answer: (A)

Bonding to enamel is stronger because enamel is highly mineralized and has a rigid, prism-based surface that responds very well to phosphoric acid etching. This creates many microporosities and long resin tags that form a strong micromechanical interlock with the adhesive, leading to a durable bond. Enamel contains very little organic material, so there’s minimal interference from collagen or fluid movement, making the bond more predictable.

Dentin, on the other hand, has a substantial organic matrix and dentinal tubules filled with fluid. After cutting, a smear layer forms and moisture can interfere with adhesive infiltration, so forming a consistent hybrid layer is more challenging and the bond is generally weaker and more technique-sensitive.

Cementum is even less mineralized and more variable in texture, which also makes bonding less reliable than to enamel. The pulp isn’t a bonding surface at all.

So, enamel provides the strongest bond due to its mineral-rich, easily etched surface that yields robust resin interlocking.