Zir bridge on implants too small

[Brett Hansen CDT]

I recently scanned a case with my DWOS 3 series. It is a lower 3 unit anterior bridge....24-26. The 2 abutments are zir custom abutments. The space is very narrow, mesial to distal, and tall. I made a waxup of the final restoration to aid in fabricating the framework. I scanned the abutments on a solid model. I scanned the waxup and designed the framework. The first framework I got back fit both abutments individually, but it did not seat completely with both abutments screwed into the solid model. It didn't seem like this bridge could have warped because it was short and the connectors were large in comparison. I rescanned the case using the same procedure. This time, the framework came back and it won't even come close to going down on either abutment individually. It looks like it was "shrunk." The bridge only goes about 1/3 of the way down on the abutments. Anyone have any ideas where my problems could be? It is possible, but not likely, that I did'nt have the abutment or abutments seated properly in the analogs on the first scan. I have never had a bridge this far off from seating on the second scan.

Here are my die spacer parameters:

Cement Gap .02
Vertical Gap .08
Horizontal Gap .03

Any help is appreciated.

 

[Marcusthegladiator CDT]

I couldn't imagine a tiny bridge warping in the sintering oven. I would mill your bridge out of pmma and see how it fits. If it fits, then you warped in the oven. If it fits as bad as the original bridge then you probably didn't have your abutments seated properly when scanning. Just a suggestion.

 

[Gabriel]

The pmma solution is good, just to see if the abutments' positions are the right ones. Sometimes after the detail scan of each abutment/stump, the DW software doesn't reposition the new scan over the old one exactly at the right position, resulting in a faulty fit. This could be an explanation for the first scan, when you said they fit ok individually.

 

[PinAn]

I recently scanned a case with my DWOS 3 series. It is a lower 3 unit anterior bridge....24-26. The 2 abutments are zir custom abutments. The space is very narrow, mesial to distal, and tall. I made a waxup of the final restoration to aid in fabricating the framework. I scanned the abutments on a solid model. I scanned the waxup and designed the framework. The first framework I got back fit both abutments individually, but it did not seat completely with both abutments screwed into the solid model. It didn't seem like this bridge could have warped because it was short and the connectors were large in comparison. I rescanned the case using the same procedure. This time, the framework came back and it won't even come close to going down on either abutment individually. It looks like it was "shrunk." The bridge only goes about 1/3 of the way down on the abutments. Anyone have any ideas where my problems could be? It is possible, but not likely, that I did'nt have the abutment or abutments seated properly in the analogs on the first scan. I have never had a bridge this far off from seating on the second scan.

Here are my die spacer parameters:

Cement Gap .02
Vertical Gap .08
Horizontal Gap .03

Any help is appreciated.

did u check the zirconia's shirk?
that sounds like shirk is wrong