I am a little concerned about this. This comes from your statement that you still have an unhealed exposed bone section in your mouth. What that tells me is that you mouths tissues, and boney structures, are so poorly vascularized that even with the dives you did, they couldn't heal. This is a long term infection waiting to happen. That can be a disaster. So that is the indicator of the condition of your mouth.

Your doctors want to extract all your remaining posterior teeth, which may be restorable, for convenience. If you have one section of your mouth that is not healing, what makes them think, even with more dives before and after, that the extraction sites will heal properly? Please take the time to have them explain this dichotomy to you, and get a second opinion before taking this leap. Only when you are satisfied that you will heal properly from all your sources (these guys in particular) should you move forward. I would like someone who is not part of the current team to confirm that given your levels of radiation treatments, what he has seen as healing potential in the past that allows him to believe this will be OK for you.

I have taken a different route. About 7 years out from treatment I started to get rampant class 5 caries around the necks of my posterior teeth. I have been proud of my dental health, lack of restorations, and healthy gingiva my whole life. The first two years the dentist was able to restore these with composite resin fillings. But because of my acute xerostomia, my gingiva (gums) continued to recede exposing more cementum (the material the root is made of) and that is very soft compared to tooth enamel, making it more susceptible to caries, so I kept getting more and more decay. We have chased this for several years now, and I am starting to get porcelain fused to metal crowns on various teeth that have been compromised in this way. 5 crowns in the last 8 months. I think that with these covering the exposed cementum, that I can get another ten years out of things minimum. Males in my family, with no cancer issues don't make it past their early 70's historically, and if that is my genetic timeline, I just want to get another working decade out of things.

My hygiene and all is impeccable, my tissue health is excellent, with tight, finely stippled tissue around all my teeth with no periodontal pockets. I get professional cleanings every two months as even with my strict compliance with brushing, flossing etc. I still cannot stop the buildup of plaque and calculus.

My solution may not be for everyone, I have friends in the dental community that I have worked with for thirty+ years, and the doc who is now doing the crowns won't take a cent from me, and my ex partner, one of the finest dental ceramists in the US, is doing the lab work for free as well. I pay for everything else like the fillings, even though the restorative general dentist does not want me to. I guess I am getting payback for the many years of helping them with implant cases and more, and my contributions through speaking at study groups, conventions, and universities for 30+ years. So my solution may not be affordable for non dental insured people. But I wish to die with as many of these things in my head as possible. I have seen too many people that are edentulous over the years, and none of them are really happy even when restored, particularly with full dentures.

I understand that your situation is different, and I kinda rambled on there about my own situation. But even with no NEED for posterior teeth in your mind, they do provide a positive vertical dimension stop for things. Without these, and without restoration of anything back there, you may have that vertical dimension collapse in time, and that can cause a whole 'nuther set of TMJ problems and further opening issues for you as if the current trismus is not enough.