Which statement about deeper cavity preparation and bond strength is correct?

Which statement about deeper cavity preparation and bond strength is correct?

• A. Deeper cavity preparation reduces bond strength
• B. Dentin moistness increases bond strength
• C. Dentin color affects bonding
• D. Adhesive type does not matter

Answer: (A)

Deeper cavity preparation reduces bond strength because bonding to dentin depends on creating a stable resin–dentin hybrid layer formed by resin infiltrating a demineralized collagen network. As you go deeper, dentin becomes more tubule-rich and wetter and less mineralized, making the surface more permeable and harder to condition uniformly. This can lead to incomplete resin infiltration and more nanoleakage, weakening the bond. In addition, deeper preparations often have a higher configuration factor (C-factor), which increases polymerization shrinkage stresses at the bonded interface and can compromise the bond further. Dentin color has no meaningful effect on bonding, and while adhesive choice matters, the substrate changes with depth are the primary reason bond strength diminishes in deeper cavities.

Deeper cavity preparation reduces bond strength because bonding to dentin depends on creating a stable resin–dentin hybrid layer formed by resin infiltrating a demineralized collagen network. As you go deeper, dentin becomes more tubule-rich and wetter and less mineralized, making the surface more permeable and harder to condition uniformly. This can lead to incomplete resin infiltration and more nanoleakage, weakening the bond. In addition, deeper preparations often have a higher configuration factor (C-factor), which increases polymerization shrinkage stresses at the bonded interface and can compromise the bond further. Dentin color has no meaningful effect on bonding, and while adhesive choice matters, the substrate changes with depth are the primary reason bond strength diminishes in deeper cavities.