thanks for sharing your concern.
i think whatever your dentist
has suggested is right.
when an old bridge pops off , it breaks some tooth structure also with it. exactly the same as happened in your case.
in that case it cannot be cemented back on the previous location. The broken tooth has to be rebuilt so that it can support the crown and bridge placed on it.
I would suggest you to take a x ray
and check for bone support around these teeth,if there is adequate bone support and your medical conditions are favourable, then you can go for implants also.
Treatment with implants is little costlier than bridge.you will have to check with your oral surgeon regarding its placement,duration and durability.
hope it helps .