Implant specialist and CDT Alex Rugh discusses Nobel Biocare’s Angled Screw Channel abutment which makes it possible to fabricate screw-retained restorations, even when the angle of the implant normally wouldn’t allow it. Alex explains how they work, what they’re used for, and some of their advantages.
What are they?
Nobel ASC abutments are made of milled zirconia and are mechanically attached to a titanium base. They use a special screw that can be accessed from an angle which allows the screw access channel to be adjusted by up to 25°.
Nobel ASC abutments can be used for single and splinted screw retained restorations in both the anterior and posterior region.
The new abutment from Nobel Biocare called the Angled Screw Channel, or ASC abutment, makes it possible to fabricate a screw retained restoration even when the angle of the implant normally wouldn’t allow it.
The way they work is through a special screw called the Omnigrip that is designed to be torqued at an angle. This screw does require a special omnigrip driver instead of the usual UniGrip driver, but it still gets torqued to 35 Ncm.
The access hole can be adjusted up to 25 degrees which is sufficient for most cases. However, there are some limitations in regard to the thickness of the abutment which are affected by the implant placement and the amount of space available.
The abutments are made of zirconia and are mechanically retained to a titanium base. The abutments can be designed as full contour zirconia crowns or with cutback for stacking porcelain directly to the abutment.
They can also be designed as a base for a Screwmentable crown such as e.max
One really nice aspect of these is that they are also available with non-engaging titanium bases so that you can utilize them for bridges.
When you are handling these abutments, take care not to lose the titanium base. The base fits semi-loosely into the bottom of the abutment and can easily fall out or detach when removing the abutment from a model or implant. When the abutment is torqued into place, the screw holds the two pieces together.