Why is a Invisalign Refinement Needed if Teeth Fit Final Tray?

just like a fine work of art there is always a little refinement that can make it a masterpiece. it will well worth the extra effort and will also help the stability

Invisalign takes a conservative approach to move teeth and with patients wearing their aligners all the time and have a perfect fit, sometimes refinements are needed. Most of the time the patient will notice something that wants to improve. Other times the doctor brings it up to the patient if more trays are needed to correct an overbite that still not completely fine. Just keep in mind there is a possibility of refinements.

Refinement is used to make slight tweaks to your case at the end of treatment to simply improve the final result.  If you are happy with the result then you do not need refinement.  Ask your dentist what changes are going to be made and then make the decision whether to continue with treatment