Do you need to brush your teeth before eating in the morning after using the pen? June 17, 2021 13:17 Updated We recommend brushing your teeth before eating as the formula will still have a layer of film on your teeth. Related articles Am I allowed to eat or drink after application? Is there any minimum hour of sleep I need to have for the product to work? Is there an interval in between treatment cycles? How much time should I wait to go through the whitening cycle again? Do my teeth have to be dry before doing the treatment? Can I use this with a mouth guard or Invisalign type of braces? Comments 0 comments Article is closed for comments.