FABRICATE (screw retained) PFM

For a single restoration choose indexed UCLAs and for a splinted or bridge restoration choose non indexed UCLAs.
 Remove the soft tissue mulange and screw the UCLA on to the analog on the working model to affirm proper seating of the UCLA on to the analog.
Reduce the height of the plastic tube to allow for adequate porcelain thickness.
Wax up the substructure to develop enough support for the porcelain.
Create a collar of at least 0.5mm thickness above the metal indexing feature of the UCLA because most implant manufacturers use a alloy not compatible with porcelain application. Some implant manufacturers (Straumann) do offer UCLAs machined with a porcelain compatible metal. 
Remove the wax up from the model and clean the index with rubbing alcohol and a cotton swab.
Sprue the wax up following the long axis of the sprue as close as possible. This will allow the investment to freely flow through the screw access channel of the UCLA when pouring the investment into the casting ring.
Preheat the muffle and cast on in a metal alloy suitable for porcelain application. Do not exceed the solidus of the UCLA during preheating. Non precious alloys should not be used for any implant restoration.
Divest the cast with a ultra sound and acid bath, avoid sand blasting.  
Finish the metal framework the same way a normal PFM would be finished. Take care not to damage the indexing feature of the cast on UCLA. To protect the index during finishing attach the cast to an extra analog. Confirm the screw slides in to the screw access channel without binding.
Opaque and apply porcelain to the finished metal frames. To keep porcelain out of the screw access channel apply some porcelain separator to the shaft of a bur and place in the screw access hole during porcelain application. Remove the soft tissue mulange to establish a ideal emergence profile.
Remove the crowns and replace the soft tissue mulange. Adjust the emergence profile to the dentists preference.
Implant restorations should only have very light occlusal contacts or even slightly out of contact. Only one occlusal contact directly over the implant is recommended. No lateral interference of any kind and the occlusal width needs to be only two thirds of the occlusal the implant restoration is replacing
Polish the collar after glazing the porcelain, utilizing a analog as a polishing protector. Confirm the screw slides in to the screw access channel without binding.