There are many reasons why your teeth might hurt after whitening, and it is important to know what is going on before you continue with the procedure. Teeth whitening Brampton strips are a type of dental bleaching that is put in your mouth and left on for a certain amount of time. Leaving these in for too long or putting them in too often can create sensitive teeth, which impact all feelings of taste, chewing capabilities, and speech. You may also experience sensitivity after having the strip soak up too much saliva from the mouth. This can be solved by either packing a tissue under your tongue for moisture or keeping sugary foods nearby to eat during the process.