The question for you is: were the Invisalign trays made before or after the missing tooth was extracted?
If the trays were made to fit over a tooth that is no longer there, then it is an easy fix to flow the right color of denture tooth into the space. If the tray dips down to the gum...
If you just started Invisalign your bite is going to feel very different every time you take them out. As you move forward with treatment you will also notice that some teeth are touching and some don't. As teeth move your bite will change, but it will feel completely normal once you have...
This is possible, most dentist and orthodontist use white filling material to fill up a missing tooth. It can come off but all you need to do is to take it back again to the dentist and they will do it for you. This will not harm your Invisalign trays and will look great!