Unreacted monomer can soak through the nail bed to cause an allergic reaction.

• A. It may lead to stronger polymerization.
• B. It reduces allergic risk.
• C. It has no effect on the skin.
• D. It can soak through the nail bed to cause an allergic reaction.

Answer: (D)

Unreacted monomer has the potential to penetrate beyond the nail plate and reach the nail bed, where it can trigger an allergic reaction. The monomer molecules are small and can diffuse into skin and surrounding tissues if they aren’t fully polymerized or properly sealed, so susceptible individuals may develop contact dermatitis or other allergic responses. This is why the statement is true: the risk comes from exposure of sensitive skin to remaining monomer during or after the nail enhancement process. The idea that it would strengthen polymerization isn’t correct—unreacted monomer indicates incomplete curing, not stronger bonding. It also isn’t true that it reduces allergic risk or has no effect on the skin; in fact, it’s the very exposure of skin to the monomer that can cause the reaction.