Background: An accurate impression is crucial to the long-term success of dental implants. This investigation evaluated the accuracy of the open and closed implant impression techniques in partially edentulous patients who received two adjacent implants.
Material and methods: Forty patients received Osstem Implants (Osstem Implant System, Seoul, Korea). Two impressions were made for each patient, one using an open tray and a second with a closed tray technique. The horizontal distances between two impression copings were measured and compared to similar measurements on the master casts. Also, under a stereomicroscope (AmScop14370, Myford Road, #150, Irvine, CA 92606 USA) at a 50-fold magnification, the presence or absence of the marginal discrepancies was evaluated.
Results: There were no statistically significant differences regarding horizontal measurements and in the marginal relationship for the two impression techniques, except between the anterior and posterior regions, for the closed tray technique. There were also no statistically significant differences in the impression accuracy between maxillary and the mandibular arches. In addition, there were no statistically significant differences for the intraoral horizontal distances, compared to similar horizontal measurements on master casts, between the open and closed tray techniques.
Conclusions: Within the limitations of the present study, there were generally no differences in the impression accuracy between the open and closed tray techniques in partially edentulous patients with two adjacent implants.
Keywords: Closed tray technique; Implant impression accuracy; Marginal discrepancy; Open tray technique.