I have a cracked tooth, probably the result of eating lots of ice as a kid. People that chomped down on ice all have cracks, I read. It's ok if the cracks don't loosen up. Cold things gave me a shot, or eating something hard. The dentist said that he could only guarantee no reaction if he took out the nerve, but being a healthy tooth in all other regards, he simply capped it. No problem with eating hard things, but cold is still slightly sensitive. i can live with it, and it might even be getting better it seems. You are right, time to heal properly is much better than killing nerves it seems, whenever possible. Kill a nerve and a part of your living is gone forever.