Abutment Level Impression - Benefits
Posted on 07/22/2011
While there are numerous challenges associated with the abutment level impression, as discussed in yesterday's blog, there are some significant benefits to this method which will be discussed today.
1. Avoiding an implant analog position transfer error: One of the most common and frustrating errors with implant restorations is the incorrect transfer of the implant position to the model. This occurs in the implant fixture level impression technique - especially common in the closed tray impression technique - as the impression coping must be replaced into the impression. Should the impression coping be placed incorrectly, or should the impression tear, the implant analog will be transferred incorrectly into the model. This is especially common for systems that rely on a hexagon shaped implant interface (Zimmer Screw Vent, MIS Six, Bio Horizons) or an octagon shaped implant (Straumann Tissue Level) - as the impression coping may be one or two degrees off when replaced in the impression. The implant analog is thus turned one or two positions off, and the final abutment and crown, while seating in the model, do not transfer correctly to the mouth. With an abutment level impression, this type of mis-transfer is completely avoided as the abutment has already been screwed down and the model must replicate the exact position of the abutment.
2. Cost Savings: The second major benefit of the abutment level impression is the cost savings. Labs who make a crown over an abutment analog or a die model will often treat it as standard crown and bridge with an additional charge for the soft tissue model and alloy surcharge since the abutment is typically smaller than a standard tooth prep. However, compared to the fees associated with parts handling and the modification of an abutment or the fabrication of a custom abutment, any small additional fees for a tissue model or alloy will be trivial.
1. Avoiding an implant analog position transfer error: One of the most common and frustrating errors with implant restorations is the incorrect transfer of the implant position to the model. This occurs in the implant fixture level impression technique - especially common in the closed tray impression technique - as the impression coping must be replaced into the impression. Should the impression coping be placed incorrectly, or should the impression tear, the implant analog will be transferred incorrectly into the model. This is especially common for systems that rely on a hexagon shaped implant interface (Zimmer Screw Vent, MIS Six, Bio Horizons) or an octagon shaped implant (Straumann Tissue Level) - as the impression coping may be one or two degrees off when replaced in the impression. The implant analog is thus turned one or two positions off, and the final abutment and crown, while seating in the model, do not transfer correctly to the mouth. With an abutment level impression, this type of mis-transfer is completely avoided as the abutment has already been screwed down and the model must replicate the exact position of the abutment.
2. Cost Savings: The second major benefit of the abutment level impression is the cost savings. Labs who make a crown over an abutment analog or a die model will often treat it as standard crown and bridge with an additional charge for the soft tissue model and alloy surcharge since the abutment is typically smaller than a standard tooth prep. However, compared to the fees associated with parts handling and the modification of an abutment or the fabrication of a custom abutment, any small additional fees for a tissue model or alloy will be trivial.
