Can a four tooth bridge supported by two natural teeth as posts be reused on two implant replacements?

There is no way to properly retrofit a tooth supported bridge onto dental implants.
There is no way to reuse the bridge in such a manner that it won't create an on healthy result
I hope you found this information to be helpful,

Dr Champagne

It's so frustrating for patients when they lose crowns or bridges due to dental decay, and the question you ask has been asked in my practice many times before.Retrofitting old dentistry to new dentistry is virtually impossible. The precision with which all of these pieces must fit is significant...like within microns! Even IF it looks like the bridge can fit (if your dentist tries to do this), if there is ANY discrepancy in the retrofit of the appliance, it can negatively affect the implant, making it fail. And then your trouble becomes very significant. I can't think of an implant company or dental laboratory who will warranty their products when used in this off-market way, so there likely wouldn't even be any kind of warranty.As well, there has been much research and discussion about the ability to attach a dental bridge to both an implant and a natural tooth, and the evidence is conflicting. Implants and teeth are each held in bone differently, so there is some extremely slight movement (like a shock-absorbing system in teeth) that there isn't with dental implants. This could be responsible for some micromovement of the bridge, or the natural tooth...and these can put pressure on the implant causing its failure. Most dentists will err on the side of caution (because research is still conflicting) in these cases by only putting an implant bridge on 2 implants, not on one implant and one tooth. Frankly, there is just too much inherent risk in attempting this kind of treatment. I know it means more cost, but when it comes to your oral health the investment is worth it. Good luck!