Update on the Accuracy of Digital Implant Impressions: A Coordinate-Based Analysis

To update data on the transfer accuracy of digital implant impressions using a coordinate-based analysis, the latest intraoral scanners (IOS) were investigated in an established clinical close model setup.

An implant master model (IMM) of the maxilla with four implants in the posterior area (maxillary first premolars and first molars) and a reference cube were scanned 10 times each with four different IOS: i700 (i7; Medit), Primescan (PS; Dentsply Sirona), and Trios 4 (T4) and Trios 5 (T5; 3Shape). Datasets were compared to a reference dataset of IMM that was generated with x-ray computed tomography in advance. 3D deviations for the implant-abutment interface points (IAIPs) were calculated. Statistical analysis was performed by multifactorial ANOVA (P < .05).

Overall deviations for trueness (mean) ± precision (SD) of the IAIPs ranged from 88 ± 47 μm for PS, 112 ± 57 μm for i7, 121 ± 42 μm for T4, and 124 ± 43 μm for T5 with decreasing accuracy along the scan path. For trueness, a significant difference between the PS and the T4 was detected for one implant position. For precision, no significant differences were noticed.

Although the latest IOS showed a significant improvement in transfer accuracy, the accumulating deviation along the scan path is not yet resolved. Considering the Trios system, the innovation seems to be limited because no improvement could be detected between T4 and T5.