Closed-Tray Impression

The closed-tray impression, or indirect impression, is an impression technique that uses an impression coping with positioning features around which a rigid elastic impression material is injected. After removal of the impression, the coping is unthreaded from the mouth, connected to a laboratory analog, and repositioned into the impression prior to pouring. A closed-tray impression is typically used when a patient’s implants are or will be mostly parallel to each other. It is not an efficient impression technique for non-parallel implants. The closed-tray technique may also be used when there is not enough room for screw-retained impression copings and/or when there is a reduced interarch distance. Another benefit of the closed-tray impression technique is that it is an efficient way to obtain an image of both the implant and the natural teeth in the same impression. To avoid any errors in the proper capture of the impression, it is important that the tray is properly seated without interference from the abutments or screws.