The best way to care for your Invisalign trays is to gently clean them using a toothbrush and toothpaste, the old fashioned way. You can also use a denture cleaner like FreshGuard with lukewarm water or Invisalign cleaning crystals. You always want to be careful about extreme temperatures that you expose your trays to because they may deform. Never chew on or pop your trays on and off when you have them in, as this can misshape them as well. You want to be very gentle and diligent at all times.