Tray 4!
Well, I put tray 4 in last night, and again it's no problem. No pain, no filing needed, no lisp! They just feel like a tighter version of the old tray, but this time my bite isn't affected, so I can close my jaw without issue. It's so funny how each tray feels so tight, and then when you move to the next one, the previous one was already seeming like a comfy old friend. I find it uncomfortable to have the trays out, my teeth feel weird, so I tend to keep them in for closer to 23 hours a day, so maybe that's why it's smooth sailing so far.