Elderly patients who use dentures may soak them in bleach (sodium hypochlorite) or boil them in boiling water to whiten tea, coffee, or cigarette stains. Both of these practices are major mistakes that will permanently render the denture unusable. Boiling water loosens the polymer bonds in the acrylic resin, causing the material to thermally expand and permanently warp (deform); that denture will never fit properly again. Bleach completely bleaches the acrylic plastic, creating an artificial, pure white appearance; even more dangerously, it dissolves the plasticizers that provide flexibility, making the denture brittle like glass and increasing surface roughness, thus accelerating bacterial growth.
