I've had a few fillings without anesthetic. My dentist told me that most of the pain of drilling is because the drill bit and tooth heat up through friction. Mo

I've had a few fillings without anesthetic. My dentist told me that most of the pain of drilling is because the drill bit and tooth heat up through friction. Modern drills have water cooling and don't heat up at all. So for shallow fillings there is no pain. My two root canal procedures did have local anesthetic though. Didn't hurt either.