1. The Thinning Enamel Trap
As we pass age 40, our outer white enamel naturally thins from normal wear and acidic diets, exposing the dark, yellow-amber dentin core underneath. Abrasive whitening toothpastes and trendy powders act like sandpaper on your teeth. They scrub away your remaining enamel and make your smile look more yellow every single day. To brighten mature teeth, you must fortify the enamel wall instead of scratching it down.