I wonder if you're having a reaction to the anesthesia? I would definitely talk to your dentist about it and also talk to your prenatal caregiver. I don't know what risk it would put baby in, but having your teeth crumbling sounds like that would be risky to baby too (ie, infection can cause PPROM, PTL, etc.). Perhaps if they used a different type of anesthesia, you might not get the reaction? It's worth talking it over with your dentist.