3Shape Custom Abutments, plus…

November 2, 2009

One of the main reasons we invested in the new D700 scanner from 3Shape was the ability to bring the design of our CAD/CAM custom abutments in-house.  Up to this point, we’ve been using our Lava scanner and remitting this type of restoration to Atlantis – a system which has worked very well to date.  However, the 3Shape software allows us to take the CAD process one step further -

Let me demonstrate -

First, we scan the working implant model with a proprietary scanning abutment provided by Glidewell Laboratories (BTW – Saylors Dental Laboratory was the first outside laboratory to obtain the full scan kit from Glidewell).  The scan of the scanning abutment is then related to a computer-generated facsimile thus insuring the accuracy of the platform’s position and orientation for subsequent modelling -

The scanning abutment is removed and the soft tissue replica is replaced on the model, which is then rescanned.  Once the tissue data is captured, the technician uses various CAD tools to model the final abutment which can then be milled in either titanium or zirconia.  We chose zirconia for this particular case as the final restoration is prescribed as e.Max Press, which is perfect for our demonstration.

Here’s the design of the final abutment -

You can see that we have placed the margin 1mm below the height of the tissue on the facial, mesial and distal.  The lingual margin is slightly supragingival (Take my word for it, I didn’t feel like taking another picture…)

At this point, we have basically duplicated the capabilities of the Lava/Atlantis system. However, 3Shape allows us to keep on keeping on…

Once we have the abutment modeled and the margin defined, a few simple keystrokes provides us with a full contour proposal of the final restoration.  Using roughly the same set of CAD tools as we used to “sculpt” the abutment, we can modify this proposal to achieve a pretty darned good image of the final restoration which can then be output to a resin printer to fabricate a pattern which can be subsequently pressed, stained and glazed.

I personally recommend that our clients do an abutment try-in to verify the fit, and to check that no change has taken place in the gingival architecture that might result in an exposed margin when the final restoration is placed.  If we run into that scenario, we can simply “drop” the margin (assuming that we have adequate material on the abutment above the implant), and the resin pattern can be easily modified to fit the “new” margin prior to pressing.

FYI – there is a small bug in the software that 3Shape is currently working to fix.  Right now, because of the proprietary nature of the scanning abutment interfaces, the software will not allow a scanning laboratory to remit the abutment data for milling while simultaneously outputting an STL file of the final restoration which can then be used to print or potentially mill the final restoration.  All files must be remitted to the milling center for fabrication.  Not a huge deal, but I expect 3Shape will find a way around this little issue.

© 2009, Jeff Saylors. All rights reserved.