Microplastics have measurable negative effects on mammalian brains. That's been shown recently.
I've never microwaved or cooked anything in plastic, and I've yelled at people who do since the 90s.
Unfortunately, I break my own teeth a lot. I've shattered three of them in my sleep. It's not fun to wake up to a giant cracking sound in your head, realize your nerve is exposed, swallow part of a tooth and need immediate dental surgery.
I started using over-the-counter night guards, which I chewed through like a fucking rabbit, little pieces of plastic all over. Finally, recently, I just paid for a "permanent" night guard.
First of all, the way this is done now is amazing. It's a 3D scan of your teeth using a tiny camera wand, and the model is built in full color directly on the screen; I even pointed out to the dental tech, on the model, a red spot where a tortilla chip had wounded me the previous week.
So they shipped me this perfect molded night guard which fits my upper teeth incredibly well, and feels like a gummy on the upper side. On the lower side, though, it has a harder shell and still takes the impact of my lower teeth. And after a few months, it's already starting to fray on the bottom.
With both these things, I have no idea what's in them. PFAS? How much of this shit am I swallowing? Wearing it all night, every night, I wonder what the hell it's leaching into my brain. I don't think there are any real regulations on what they put into them, and they're clearly extraordinary mixes of different plastics.