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Updated: Oct 29, 2026
Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Accuracy of complete arch implant intraoral scans: A systematic review of different technique categories compared
Junying Li1, Jiayi Lu2, Zhaozhao Chen3
1Clinical Associate Professor, Department of Biologic and Materials Sciences & Prosthodontics, University of Michigan School of Dentistry, Ann Arbor, Mich.
Statement Of Problem:
The accuracy comparison results between a conventional impression and an intraoral scan for a complete arch implant are mixed and unclear.
Purpose:
The purpose of this systematic review was to compare the accuracy of different categories of complete arch implant intraoral scan techniques with the conventional abutment-level splinted open tray impression technique.
Material And Methods:
A comprehensive search of the PubMed, EMBASE, and Web of Science databases was conducted to identify eligible studies. Complete arch implant scan techniques were classified into 5 categories: IOS-O, regular intraoral scan only; IOS-SA, intraoral scan with scan aid; IOS-CHS, intraoral scan with horizontal scan bodies oriented toward the center of the arch to reduce scan span; IOS-CISP, intraoral scan with auxiliary structures followed by calibration with a high-accuracy scan of the auxiliary structures to correct stitching errors in the intraoral scan; IOS-IPG, intraoral photogrammetry. The accuracy outcomes were extracted and analyzed using both descriptive statistics and meta-analysis. Subgroup analyses were conducted based on short implant span (span within premolar to premolar) and long implant span (span longer than premolar to premolar).
Results:
Twenty-three studies, including 22 in vitro studies and 1 clinical study, were included in the present systematic review. IOS-O was investigated in 22 studies, IOS-SA in 10 studies, 2 studies for IOS-CISP, 1 study for IOS-CHS, and no available study for IOS-IPG. Descriptives analysis showed that IOS-O and IOS-SA presented better accuracy than the conventional approach in short implant spans but worse accuracy in long implant spans. IOS-CISP showed better accuracy than the conventional approach in long implant spans. Meta-analysis also showed that IOS-O and IOS-SA were more accurate than the conventional technique for short spans but that the conventional technique was more accurate for long implant spans.
Conclusions:
In an in vitro setting, IOS-O and IOS-SA demonstrated higher accuracy than the conventional technique in short-span implant scans. In long-span implant scans, conventional techniques were more accurate than IOS-O and IOS-SA. IOS-CISP appeared to be more accurate than conventional techniques in long spans, but the evidence is limited. Studies comparing IOS-CHS and IOS-IPG with conventional approaches are insufficient.
