Advances in dental implant impressions

Retention slots and an internal rim provide mechanical retention to keep impression material in the tray. Should the practitioner choose to supplement the retention with a PVS adhesive, it is recommended that it not be applied to the foil surface because this may obscure visualization of the pins when inserting the tray to proper depth.

The technique involves filling the tray with an appropriate impression material. The tray is then inserted over the open tray impression heads intraorally and pressed down crestally until the top of the impression pins are visible through the transparent foil. The practitioner then presses the tray further until the pins puncture the foil and are visible protruding through the foil. This contains the impression material within the tray without the potential problem often seen with use of custom or modified stock trays of the impression material obscuring the tops of the pins.

Upon setting, the pins are rotated in a counterclockwise fashion and removed from the impression, and the impression is removed intraorally. Because of the design of the tray, it can be used in all implant impression situations, whether the arch is partially dentate or fully edentulous.

Case example

Patient presented ready for prosthetic phase of a single implant in the maxillary second premolar and an adjacent crown on a natural molar. The treatment plan would restore the implant at the second molar with a custom abutment and restore the site with a cemented bridge with a cantilever pontic at the first premolar. Following preparation of the molar, an open tray impression abutment was placed on the implant fixture.

The Miratray was tested in to verify it was large enough to capture all of the teeth in the arch without impingement on teeth or soft tissue. An impression material was injected around the gingival aspect of the open tray impression abutment and the sulcus of the molar preparation. The Miratray was filled with additional impression material and inserted intraorally.

As the tray was pressed gingivally, the long pin was allowed to perforate the clear foil on the occlusal aspect of the Miratray. Upon setting, the long pin was removed, and the Miratray impression was removed intraorally and sent to the lab for prosthetic fabrication. A master cast was created from the impression and the prosthetics were completed and returned for insertion.

Note: This article was published in Dental Tribune U.S. Edition, Vol. 7, No. 4, April 2012. A complete list of references is available from the publisher.