Blurred Lines: GPS Overdenture Case Saved by SICAT

One of the things I love about Sirona’s guide lab (SICAT), is that they look at your scans and will let you know if there is a problem.  Here is a case where we went through all the right steps, but had some errors along the way and corrected them.  Patient wants just a little stability with a lower denture.  Not happy with the set up.  Tried to talk them into a 4 implant bar supported over denture but due to finances they just wanted a two implant stud type with GPS attachments.  Well I live to serve, so we made a duplicate denture in clear acrylic and Barium Sulfate and had it attached to the Classic Guide bite plate.

 

 

The big issue was that with the ball attachment on the Galileos the denture kept moving.  We tried everything, standing, sitting.  Finally, I went all MacGyver on it and nixed the ball attachment and just had her bite on some bite registration using the chin rest.  I thought everything was cool and sent it to SICAT, guess not.  One thing that is very important in edentulous cases is that the FLANGE of the radiographic guide has Barium Sulfate in it as well.  You can see that the denture moved buccal.  So abort..abort..  Which sucks as these radiographic guides cost about $300 to make.  What to do?

 

 

We had the patient go back to the lab (Burbank) and they made a second duplicate which was used to make a surgical guide with two pilot sleeves and some Nobel pin channels.  I used landmarks on the denture (first pre-molars) to determine where the mental foramen was to place my pins.  I also looked at the original scan and drilled on the model to find the ridge.  Not nearly as good as CBCT based guides, but in a pinch this worked.  The patient was moving to the east coast in 2 weeks so I had to place the implants AND fabricate the over denture.  No rest for the wicked!

 

 

Secured the guided with the Nobel 1.5mm pin drill.  This drill is well…1.5mm wide so if you drop it you are screwed as these bend easy (ask me how I know), so buy a few.  Nice and secure.

 

Implants placed with the 2.3mm pilot.  These will be 4.2 by 13 Legacy 3s, so all drills after the 2.3 were non guided.  No worries though as this was D1 bone.

 

 

Went up to the 3.8mm drill, took an impression with the closed tray impression copings/fixture mounts with a little cotton and cavit.

 

 

Used the guide as the occlusal rim as the lab duplicated  the denture and it already had the occlusion and the vertical.  Just stabilized with hand pressure. I was hoping the pins would clear the bite so I could have it more stable, but alas no, the pins were in the way.

 

 

The lab incorporated the GPS attachments into the waxed up denture for stability.  Patient happy with the arrangement and bite.

 

 

 

 

GPS attachments torqued down to 30 Ncm.  Finished the day before she left!