Accuracy of Intra-oral Scans Compared to Conventional Impression in Vitro

Abstract

AIM The purpose of the present study was to assess the accuracy of intra-oral scans and conventional impression measured at various points on a single tooth preparation. Methods Ten conventional silicone impressions, and ten intra oral-scans using eight different digital intra oral digital scanners were taken of a prepared master tooth. The conventional impressions were directly digitised using a laboratory scanner. Each scan/impression was superimposed on a high-accuracy digital model of the prepared master tooth. For each superimposition, the deviation from the prepared master tooth was measured at six points on four two-dimensional cross-sections. Data was analysed using two-way analysis of variance (ANOVA). Results Most intra oral scanners had lower accuracy at the preparation margin compared to smooth surfaces. When only conventional impression and the latest intra oral scanners of various manufacturers are considered, the mean discrepancy at the preparation margin was 50μm (SD 16) for conventional impression, 15μm (SD 4) for Trios 3, 26μm (SD 4) for LAVA TDS, 29μm (SD 7) for CEREC Omnicam, 30μm (SD 6) for CS 3600 and 64μm (SD 7) for GC Aadva. The increased accuracy of Trios 3 was statistically significant (p<0.05). Conclusions At the preparation margin, Trios 3 performed significantly better than conventional impression and the other intra oral scanners. LAVA TDS, CEREC Omnicam and CS3600 showed similar accuracy at the margin, yet better than conventional impression and GC Aadva.

Marginal and internal fit of crowns based on additive or subtractive manufacturing

“…Well-established intra-oral scanners have been shown to perform equal to, if not better than conventional impression methods with addition-cured silicone materials, particularly for shorter spans such as a single tooth, up to a quadrant [ 3–5 ]. The manufacturing phase for a fixed prosthetic restoration, after a scan is obtained and a restoration has been designed, is currently subtractive manufacturing (SM), i.e.…”

Accuracy of Digital Impression Taking with Intraoral Scanners and Fabrication of CAD/CAM Posts and Cores in a Fully Digital Workflow

“…Haddadi et al investigated the accuracy of digital impressions of multiple IOSs in comparison to conventional impressions based on single tooth preparation [39]. The measurement area "Prep Margin" can be considered comparable to the occlusal external measurement area.…”

“…The measurement area "Prep Margin" can be considered comparable to the occlusal external measurement area. The values for the mean deviation in the study differed depending on the IOS [39]. The two IOSs they used were the IOS Trios 3 and the IOS Omnicam [39], which represent the previous generations of the IOS Trios 4 and IOS Primescan.…”

“…The values for the mean deviation in the study differed depending on the IOS [39]. The two IOSs they used were the IOS Trios 3 and the IOS Omnicam [39], which represent the previous generations of the IOS Trios 4 and IOS Primescan. They determined the mean deviation for these IOSs, which was smaller than that of the respective successor [39].…”

“…The two IOSs they used were the IOS Trios 3 and the IOS Omnicam [39], which represent the previous generations of the IOS Trios 4 and IOS Primescan. They determined the mean deviation for these IOSs, which was smaller than that of the respective successor [39]. The use of the IOS and that the accuracy of the current generation of the IOS may have played a role in these differences.…”