Drinking coffee while wearing Invisalign is strongly discouraged by dentists for several reasons. First, the heat from hot coffee can warp the medical-grade plastic of the aligners, ruining their precise fit and potentially stalling your progress. Second, coffee is notorious for staining; it can quickly turn your clear, “invisible” trays into a noticeable yellow or brown shade. Even more importantly, if your coffee contains sugar or cream, these liquids get trapped inside the trays and sit directly against your enamel for hours. This creates a perfect environment for bacteria to grow, significantly increasing your risk of developing cavities. If you must have coffee, it is best to remove the trays, drink it quickly, and brush before reinserting them.