Not at all! We will clean your teeth, use a cotton roll to keep them dry, and carefully glue the braces or Invisalign attachments on. Later that night you may feel some temporary soreness/discomfort as the teeth begin to move. This will last a couple days after your appointments, or after you switch your Invisalign trays. It is generally a very mild sore feeling that can be minimized with whatever medicine you would take for a headache.