Does most movement occur only when you first change your trays, or are teeth constantly moving? My trays are always loose a few days after receiving a new tray, and they are only sensitive for a few days. Also, does IPR help move teeth faster? Or is it just a necessity if you have tight teeth? I have pretty significant gaps on my problem areas. after recent IPR. My dentist used a mini saw-like drill, looked like a little disc. Does this wear off enamel?