In composite resin restorative dentistry, what is the purpose of a bonding agent and the sequence of application with etchant?

• A. Bonding agent strengthens enamel; Sequence: apply bonding agent first, then etch enamel for 60 seconds.
• B. Bonding agent promotes adhesion between dentin and composite. Sequence: etch enamel for 15–30 seconds, rinse, lightly air-dry, apply bonding agent, air-thin, light-cure.
• C. Bonding agent is cosmetic only; Sequence: etch enamel for 5 seconds, rinse, apply bonding agent, cure.
• D. Bonding agent neutralizes acidity; Sequence: rinse, apply bonding agent, etch enamel.

Answer: (B)