Comparative study of conventional and digital implant impression techniques with different implant angulations (in-vitro study)

Abstract Purpose Comparing cast accuracy of unsplinted open tray implant impression technique to digital impressions at different implant angulations using two measurement methods [Coordinate Measuring Machine (CMM) and Geomagic software]. Materials and methods Two mandibular completely edentulous epoxy resin models (A and B) representing a clinical scenario: model A four implant analogs parallel to each other, two at the canine region and two at the first molar region, and model B four implant analogs with different angulation; two at the canine region with 15º angles, and two at the first molar region with 30º angles. Impressions were taken 15 times for each technique (direct unsplinted conventional impression technique and digital impression using an extraoral scanner). Casts obtained from the conventional and the digital techniques were measured by a CMM and Geomagic software. Data were collected and statistically analyzed. The level of significance was set at P value less than or equal to 0.05. Results Statistically significant differences in accuracy were found between the two groups; in conventional impression ( P ≤ 0.05) whereas in digital ( P ≥ 0.05). Conclusion There is a difference between digital and conventional impressions, with digital impressions exhibiting a greater resemblance to reference measurements. This difference is clinically acceptable for parallel implants but not for angled implants. The angulation did not affect the accuracy of the digital impression. Both CMM and Geomagic software resulted in the exact measurements with the same accuracy and difference between them.