Resin tags contribute to bonding by providing what mechanism?

• A. Micromechanical interlocking
• B. Chemical reaction with dentin
• C. Thermal conduction
• D. Adhesive bonding

Answer: (A)

Resin tags contribute to bonding by providing micromechanical interlocking. After dentin is etched, the demineralized collagen and open tubules present a rough, porous surface. The adhesive resin infiltrates these microfeatures and tubules, and as it cures, it forms slender resin extensions that penetrate into the dentin. These tags physically lock into the surrounding dentin matrix, creating a strong, interwoven connection—the resin-dentin hybrid layer—so the bond stands up to stresses through mechanical retention rather than relying on a chemical reaction alone.

Chemical reaction with dentin would imply a true chemical bond with the mineral or organic matrix, which isn’t the primary action of resin tags. Thermal conduction is not a bonding mechanism, and adhesive bonding is a broad idea that’s achieved here specifically through micromechanical interlocking, not just by general adhesion.