I've never had this problem exactly, but I'm anticipating it developing with my lower left first molar. It fractured vertically in two places, I'm in the process of having a crown placed on it. But it still occasionally aches. I don't know if this is because of the temp. crown or the teeth hitting it or an infection or what, but if it's still fractured below the gum line, my thinking is that it's better to extract it than wait for it to become infected. Have you thought about what you will be doing for the space in your bite? I'd err on the side of caution re: the extraction, as it's a molar and you've already had problems with it. An oral surgeon might cost more, but it will probably be a safer, quicker experience, even if your dentis is great. As has been pointed out, if there are complications, you'd end up there anyway. It's a tough choice to have a tooth extracted, esp. a molar. Good luck--I'll be wanting to hear how it resolves.