I'm sorry to hear of your dental
troubles. Unfortunately, with what you've described, it sounds as though that front tooth will need to be extracted. There are only a certain number of times that the tooth/root is good for in terms of restoring and replacements and it appears its number is XXXXX
You have a number of options:
1) Extract the tooth and be fitted with a removable partial denture
(RPD). Oftentimes, these are referred to as "flippers" because of patient's tendency to play with them and pop them in and out with their tongue.
2) Extract the tooth and assuming the adjacent teeth are healthy, restore the gap with a fixed partial denture (FPD). These are oftentimes referred to as a "bridge." They are fixed so you would not have to take them in and out. The downside of bridges is that they do require more maintenance/home care. You have to be diligent to floss
along the margins and underneath the "fake tooth" to prevent recurrent decay
from forming at the margins. If a new cavity
forms on the supporting teeth, the entire bridge often needs to be completely replaced. (A Maryland bridge would fall under the FPD category.)
3) Extract the tooth and restore the area with a dental implant
and crown. This is the most ideal way, however, it is also the most expensive treatment. The benefits of going with an implant is that you never involve the adjacent teeth, so you're able to floss and care for the implant as if it's one of your natural tooth. Should anything ever happen to the implant itself, it doesn't jeopardize the teeth next to it. And the same is true in that should a cavity form on the adjacent tooth, it doesn't jeopardize the implant.
From a long-term perspective, option #3 is the most ideal because single-unit implants have a great track record and do last a long time. Bridges typically need to be replaced every 5-15 years (sometimes longer). Most patients do not like dentures (RPD) because they're bulkier and people get tired of needing to take them in and out, or sometimes misplace them. However, RPD would be the least expensive treatment that would be offered.
I would advise against trying to splint the existing, broken crown to the adjacent teeth because by this time, there is a gap that we cannot reliably seal underneath the crown. This will eventually lead to recurrent decay as well as cause the existing root canal treatment to fail. And infection
will form at the root tip, resulting in bone loss.
I hope I was able to address your concerns. If you have additional questions, just let me know and I'll try my best to answer them for you.