I think you would have problems with a peek bridge in those dimentions
That's speculative. If you've seen shear and bending stress maps you'd notice that the properties of a material make a huge difference to the type, location and required force of failures. Also you're only looking at restorative failures. Implant failures happen too, longevity of the implant is highly affected by the restoration, passivity is the obvious one, but occlusion/load distribution is also important.
That being said, dealing with flexible materials for fixed restorations is not something we're accustomed to in north america. I'd be interested in seeing the type and frequency of failures that our European counterparts have experienced thus far.
Scary finding of a recent study; They looked at the distance cross-arch between the second mandibular molars at rest position, and then measured it again at full opening. Results showed the mandible flexes by more than 1mm! A full arch restoration made out of practically every material we currently use today would NEVER bend that much.
So where's all the stress going? Has it been detrimental all this time causing implant failures which we believed were idiopathic failures? Is it worse the larger the A/P spread is? Do flexible materials help?
We'll only know with comparative studies. The plural of anecdote, is not evidence. I'd like meta-study level proof, but from what I've seen thus far, it looks very promising.