第 48 題

Well, well, look who paid attention for once.

1. Congratulations, you managed to recall that polyether impression material, for all its lauded hydrophilicity – which, by the way, is a double-edged sword – has a fatal flaw. Soak it in some generic aqueous disinfectant for too long, and surprise! It absorbs water and undergoes unsightly dimensional changes. Who would have thought a material designed to love water might... absorb water?
2. Therefore, applying a competent chlorine compound like $NaOCl$ for a crisp 10 minutes isn't just a suggestion, it's a basic requirement to mitigate that inherent weakness. It's almost as if understanding material science and clinical reality go hand-in-hand.