Screw Access Mark for Cemented Implant Crowns: A Universal Technique to Simplify Retrievability
The use of cemented implant prostheses for partially edentulous patients continues to increase in clinical practice. One of the primary complications of the cemented implant crown is difficulty in retrieval, should the need arise. Drilling through most prosthetic materials is of little difficulty for most clinicians, but the complication lies in determining where exactly the access hole needs to be drilled. During fabrication, the location of the screw access channel is marked with a strong contrasting color stain on the surface of the prosthesis. The technique proposed here marks the location of the screw access directly on the prosthesis, thus improving the ease and predictability of future retrieval.
Figure 1. Traditional screw-retained porcelain fused to metal prostheses are relatively easy to retrieve due to the common effect of discoloration of the composite covering the screw access. Figure 2. Screw-access marking on a cemented prosthesis creates the same intuitive approach to retrieval of the cemented restoration. Figure 3. Surveyor is used to determine the angulation and position of the abutment screw access channel. Figure 4. Small divot is created in the prosthesis at the location where the screw access channel would exit as recorded by the surveyor. Figure 5. Opaque white or opaque brown porcelain stain is placed into the divot. Figure 6. Restoration is stained, glazed, and fired to completion. Figure 7. Definitive prosthesis in the mouth with the screw access marking indicating where the screw channel is located. Figure 8. First premolar crown has developed an unfavorable embrasure with the adjacent canine and needs to be replaced. The screw access marking is clearly visible on the occlusal surface. This mark indicates where to drill to find the screw channel. Figure 9. Screw access channel has been located and the screw covering has been removed allowing easy access to the abutment screw for retrieval.
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