Your teeth may be tender for 3-5 days each time you progress to the next aligner. It may take a few days to get used to wearing the clear braces. If necessary, painkillers such as the ones you normally take for headaches may help (always read the instructions). If possible do not stop wearing your Invisalign clear aligners or else you will have to go through the 3-5 days of discomfort all over again.