The crack is at the front down the middle. It would cost > $100 to get a new one. Is there any type of glue I can use that is harmless inside the mouth when dried?
The retainer still feel ok even with this crack. However, if I don't fix the crack, it would probably get longer and eventually the retainer would break into two.
I cannot afford to keep buying $100 retainer every month for the rest of my life, so I'd like to learn how to repair them.