I would want to know if the tooth is the terminal abutment for a distal extension
RPD. Hopefully there is another abutment to the distal so this is a bound saddle instead.
There would be so much involved in getting the right height of contours to disengage,
etc in a distal extension for it to fit and function the same way and the way it should
to recreate as surveyed implant crown.
Really, I would have considered an UCLA cast to just for the right rest seat and
guideplane considerations. Otherwise, wax to ideal and press something like an emax
crown that can be luted to the Ti-base or other prefab abutment.
And the clinician needs to physiologically adjust the interfaces .
Like RKM said, what was the condition of the RPD - if it needs a reline for distal extension
tissue support, making the crown fit the partial would not solve that problem at all
and the patient would likely tell once he wears it or when he eats to say it does
not fit right.
Might be so much easier to add a tooth to the partial, and clinically pick up a Locator or Equator
abutment.
Good luck,
LCM