This was especially true with the old metal based fillings (gold, silver, etc). The metal contracts and expands a miniscule amount with heat and cold. Eventually they end up cracking the tooth. The larger the filling, the worse it is.
I am on crown #5 because of that asshole dentist when I was 23. Oh and a nice plus is they were extremely sensitive to temperature and randomly hurt like hell. At $1000 per crown it’s not fun on the pocket book.
It’s a shit ton harder than people realize… well at least to go anywhere in the industrialized world. Unless you are independently wealthy or have an extremely high demand job.
Billy Bob who’s career is working at McDonalds isn’t going to get approved.