I know you said you don't want a bridge or whatever... have you considered (or even discussed with your dentist) having an implant? My husband had one of his crumble about a year ago. He had had sudden pain every once in a blue moon with that particular tooth, for a year or two. But they couldn't find anything wrong with it (believe me they tried to...)... some things just don't show up on xrays... Anyway... it finally just split in half, and when he went in to the dentist the next day and he went to pull it, it just crumbled. He went ahead with having an implant done (it takes a few appts, the socket has to heal from the tooth removal, then they screw in the actual implant --a titanium root, essentially) and that has to heal. Then a few months later, they attach the fake tooth to the implanted root. That was about a year ago that he finally finished up all of it.... and he hasn't had a single issue with it since. And the titanium root will protect the integrity of his jaw bone. (The bone actually fuses with the titanium!)
My husband is 43 and never had any other tooth problems.
It was spendy (about $3,000 for EVERYTHING) and it wasn't covered by the insurance we had at the time, but it happened just before the end of December, and we were able to put enough $ into our HSA to use, so that at least it was taxfree $.
He recovered from the implant surgery (pain wise) within about 24 hours. But he was still required to use care and brains when eating for several days after that. Then he wasn't allowed to have hard things (peanuts/popcorn) for a bit longer.
I have no idea how that compares price-wise, with just a root canal and a bridge... But to my husband, it was worth every penny.