IPR Needed for Invisalign?

There are several ways to open space orthodontically with having to shave between teeth (IPR). Expanding your arches, and pushing teeth forward more towards your lips, will create space b/c they will fit into a larger circumference in terms of your arches. This may be a way to avoid IPR (if you have minimal to no gum recession).

In the case that you do need IPR, your practitioner can choose to do it in areas where you have not already had it, or they can evaluate and do less where you have already had it. Regardless, you should not have increased sensitivity if the procedure is done correctly.

IPR should not cause sensitivity. There have been long range studies on this question. The studies have not shown increase decay or sensitivity.

On the other hand, we hardly do any IPR now days. We don't do IPR much with braces so why do it with Invisalign? We spread the teeth first with Invisalign so the teeth will move then close all spaces at the end. Every appointment we check for IPR because Invisalign is not perfect. Teeth will not move when they are touching using Invisalign. Still we try to avoid any IPR

Often the teeth are smoothed after orthodontics and/or Invisalign. If the smoothing in your case was done on the tops (biting surfaces) of the teeth, this is different from IPR. IPR stands for Inter Proximal Reduction. Make sure you discuss this with your dentist before he/she submits your case to Invisalign for the ClinCheck set up. It is sometimes possible to have the case set up without needing IPR. It may sometimes take longer to achieve the results without IPR, but it is often possible.
If you do need IPR to complete your case, your dentist can still control where and how much is done in each area.