this is not really a new idea as a few implant companies have tried
this idea before.

it is my opinion that this wasnt possible until recently as with the
new accuracy in scanning and milling that we now have today.

if your dentist is using the nobel biocare procera scanning system and
it is scanned and produced in sweden...there is usually no problems.

my lab uses sweden and new jersey scanning centres for fabricating a
crtical part of a 'ceramic' crown.

8 implants for your top sounds pretty good and if they have integrated
properly should provide you years of function and aesthetics.

if you are going with a fixed bridge for your top.  one important thing
to keep in mind that keeping your implants clean daily is really
important.  if it is hard to clean underneath, it makes it so that it
is difficult to get everything out and 'most' people tend to eventually
get lax about it.

if you are getting individual units (single teeth that you can
individually floss) then make sure that your dentist try to minimize
any black triangles that may form.  these are either the easiest things
to do or can be very difficult.

i was at an international implant symposium a few years ago with
doctors showing their latest fixed bridge implant work.  looked great
but also looked like a nightmare for the patient to keep clean.

it will be up to you and your dentist to come up with game plan on how
to deal with these topics.