Many patients may experience a little discomfort in the first few days of using the system, due to the pressure exerted on your teeth to align them. After a while, your teeth and mouth will become used to the pressure from Invisalign and you will begin to notice it less and less. In the event that you do find some on-going discomfort, you can use ordinary pain relievers such as paracetamol to help minimise any mild to moderate soreness.