Intraoral Scanners Beat Conventional Impressions on Interdental Areas in Vitro

Edited by Dentaltown staff

Every intraoral scanner tested reproduced the interdental areas of a periodontally compromised model more accurately than a conventional impression, but performance varied widely among scanners, according to an in vitro study published Aug. 7 in Clinical Oral Investigations.

Investigators captured a standardized model of a periodontally compromised dentition with one conventional polyvinylsiloxane impression and five intraoral scanners: four wireless systems, the Dexis IS 3800 W, Medit i700w, Primescan 2, and Trios 5, plus the wired Primescan AC. They analyzed raw scan data, digitally mounted casts after scan repair, and digital casts following automated tooth segmentation in CAD software.

All the scanners reproduced interdental areas significantly more accurately than the conventional impression, at P less than .001.

Differences among the scanners were substantial. Primescan 2 achieved correct interdental reproduction above 80%, while the Dexis IS 3800 W and Trios 5 fell short of that mark by as much as 20 percentage points. Scan repair marginally improved interdental capture for some scanners, while the conventional impression showed no change.

Automated segmentation proved uneven. Errors clustered in teeth with pronounced gingival recession, and accuracy was higher where gingiva was healthy. Significant differences between raw and segmented data appeared for the Trios 5, at P = .027, and the Dexis IS 3800 W, at P = .044.

The authors concluded that intraoral scanners outperform conventional impressions for interdental reproduction in compromised dentitions, that accuracy varies among systems and tracks with raw scan quality, and that automated segmentation is reliable around healthy gingiva but challenged by periodontal defects.

Katharina Klaus, Linus Vincent Hardt, Bernd Wöstmann, Sabine Ruf, and Maximiliane Amelie Schlenz conducted the study.

The work was laboratory-based, using a single standardized model rather than patients. It measures reproduction accuracy and software behavior, not clinical outcomes, so the findings do not establish that digital impressions produce better restorations or appliances in periodontally compromised patients.

Sources:
Clinical Oral Investigations, “Capturing of interdental areas with digital and conventional impression systems and their impact on automatic tooth segmentation in CAD software: an in vitro study,” published online Aug. 7, 2026: link.springer.com/10.1007/s00784-026-07069-2
DOI: doi.org/10.1007/s00784-026-07069-2