It is important to confirm before taking the open-tray impression that you will be able to have access for removal of the impression post. Case study This case study shows an open and closed impression for comparison purposes. Tooth #29 had been replaced with an implant four months previously and is now ready to be restored. The first impression is taken with a closed technique. In Fig. 2 (p. 81), the final impression has captured the impression post imprint. The impression post is then unscrewed from the implant and carefully inserted into the impression and sent on to the lab. Next, we used an open technique. Fig. 3 demonstrates on the lab model what this would look like in the mouth, with the impression post sticking out well above the occlusal plane, allowing for the post to be unscrewed and released from the implant before the impression is removed from the mouth. Fig. 4 shows the final impression using the open technique. Both impressions were sent to the lab and poured up. We asked the technicians to choose which impression they thought would be most accurate, and they decided to work with the open-tray impression. Fig. 5 shows the soft-tissue working model with the implant analog in place. Using this model, the final screw-retained PFM implant crown is fabricated and ready for delivery in Fig. 6. At delivery the fit and aesthetics were excellent, and the seat appointment required less than 10 minutes to complete. Open- and closed-tray impressions for implants can both provide the desired results, given attention to detail and good technique and materials. However, one technique does not fit all clinical situations. The clinician is wise to judge each case individually and determine which technique is best. Having these two options available will allow you to consistently make the best choice for your patient and provide excellent results. ■ Fig. 6 dentaltown.com \\ JUNE 2018 93http://www.dentaltown.com