Önöral Ö, Çakır S. Influence of the color of 3D-printed scan aids on the trueness of complete arch digital scans. Journal of Prosthodontics. 2026;35(4):561–573.

In a recent article published in the Journal of Prosthodontics, Near East University (NEU) researchers from the Faculty of Dentistry investigated a surprisingly simple question with important clinical implications: can the color of a 3D-printed scan aid influence the accuracy of a digital dental impression? Led by Assoc. Prof. Dr. Özay Önöral and Dr. Selin Çakır, the study demonstrates that even the color of a small auxiliary device used during digital scanning can have a measurable impact on how accurately implant positions are captured.

Digital impressions have become an increasingly important part of modern implant dentistry, offering patients a faster and more comfortable alternative to conventional impression techniques. However, scanning completely edentulous (toothless) arches remains challenging because there are few natural landmarks to help intraoral scanners accurately reconstruct the three-dimensional anatomy. To overcome this limitation, clinicians often use 3D-printed scan aids—small guiding structures attached to scan bodies that help scanners recognize implant positions more precisely.

The NEU team set out to determine whether the color of these scan aids affects scanning performance. They produced identical scan aids in grey, beige, white, red, and blue using 3D printing technology and compared how accurately each color reproduced implant positions during complete-arch digital scanning. By evaluating angular and linear deviations from a highly accurate reference model, the researchers assessed the “trueness” of each digital impression.

The results revealed a clear pattern. Grey scan aids consistently produced the most accurate digital scans, followed by beige and white. Red and particularly blue scan aids resulted in greater deviations. While all color groups remained within clinically acceptable limits for linear accuracy, only the grey, beige, and white scan aids met the recommended threshold for angular accuracy, making them the most reliable options for complete-arch implant scanning.

The researchers explain that intraoral scanners rely on reflected light to reconstruct three-dimensional surfaces. Different colors interact with light in different ways, affecting how efficiently the scanner detects surface geometry. Grey materials appear to provide an optical balance that allows more reliable image acquisition, whereas blue and highly translucent materials may reduce scanning accuracy because of the way they scatter or reflect light.

Although changing the color of a scan aid may seem like a small design choice, the findings highlight how seemingly minor factors can influence the precision of digital implant workflows. By identifying the most suitable colors for 3D-printed scan aids, this research provides practical guidance for clinicians, dental laboratories, and manufacturers seeking to improve the accuracy and predictability of fully digital implant treatments.

To learn more about the study or explore potential research collaborations, Dr. Özay Önöral can be contacted at [email protected].

About the researcher

Dr. Özay Önöral is an Associate Professor and Vice-Dean at the Faculty of Dentistry, Near East University, where he completed both his dental and doctoral education, graduating as valedictorian in 2014. His research focuses on digital dentistry, material science, 3D printing, and additive and subtractive manufacturing technologies. Alongside his academic and administrative responsibilities, he coordinates undergraduate and doctoral courses on 3D fabrication, contributes to professional dental organizations, and serves as an editor and reviewer for international journals.

Disciplines: Prosthodontics, Digital Dentistry, Dental Materials, 3D Printing, Additive Manufacturing,

For collaboration and inquiries, he can be reached at [email protected].

Abstract

Purpose: To determine the influence of using 3D-printed scan aids in varying colors on the trueness of digital scans.

Materials and Methods: A master cast with five multi-unit analogues was scanned. The acquired dataset was exported to standard tessellation language (STL) file format to serve as the reference STL. 3D printing of the prototype in five distinct colors (beige [SA^BEIGE], grey [SAGREY], white [SA^WHITE], red [SA^RED], and blue [SA^BLUE]) of polylactic acid filament was executed. The experimental STLs of each color group were aligned to the reference STL. RMS values were solely computed for the scan bodies. Based on the centers of the created best-fit and offset planes, scan bodies were converted into virtual cylinders. Cartesian coordinates of each cylinder were acquired. Subsequently, angular (AD) and linear deviation (LD) values were calculated. LD was further examined separately along the x, y, and z axes. Data were statistically analyzed.

Results: According to the results of one-way ANOVAs, significant differences were detected among color groups on AD, LD, RMS estimate error, ∆x, ∆y, and ∆z data. The lowest AD and LD values were exhibited by the SA^GREY group in all implant sites. The SA^GREY group was followed by the SA^BEIGE, SA^WHITE, SA^RED, and SA^BLUE groups.

Conclusions: The SA^GREY outperformed the other groups in terms of trueness. Although the LD values of all color groups were below the threshold value (<100 µm), only the AD values of the SA^GREY, SA^BEIGE, and SA^WHITE groups were clinically acceptable (<0.5°).

Keywords: complete arch scans; digital implant impression; impression accuracy; scan aids; superimposition.