Taking An Impression Over A Fixed Abutment
After preparing a fixed or pre-angled abutment chairside, the abutment can be re-seated to the implant and treated in the same manner as a prepared natural tooth, or a conventional post & core restoration. An impression of the abutment is recorded by the clinician and poured-up by the laboratory, using conventional crown and bridge techniques.
In case the crown margin as prepared on the abutment is subgingival, packing cord, or using an alternate margin exposure technique around the abutment will ensure the proper transfer and reproduction of the margin.
Once the impression has been recorded, a provisional crown can be attached to the abutment to offer the patient functional use of the implant and to help in the contour of the soft tissue. Note: Fill or cover the screw access channel with gutta percha, cotton tablets, etc, to keep cement from filling the hex hole of the screw. At the laboratory, the impression should be poured using resin, epoxy, or a very strong stone, to insure the dies are not subject to potential fractures. Fabrication of the restoration is accomplished using traditional crown & bridge techniques. Note: Be sure to use die spacer on the dies to allow space for cement when seating the crown chairside. Final seating of the crown is accomplished by using either temporary or permanent cement. Removal of the final restoration if ever desired is accomplished in the same manner as removing a crown from natural dentition.
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