Clinical identification and classification of scanning errors in intraoral digital scans

To systematically identify and systemize scanning errors encountered in clinical practice using a classification framework applied to intraoral scans (IOS). A retrospective review of IOS was conducted in a private prosthodontic and implantology practice. All scans were examined for recognizable errors grouped into four main categories: (1) hardware selection reliability-related errors (scanner selection) and geometry distortions (implant scan body or ISB selection), (2) software selection and processing (scanning noise, ISB overcontouring, and shape alteration), (3) patient-related (humidity errors and scanning artifact), and (4) operator related prescan preparation-related errors: bridge errors, fuzzy finish line errors, and tissue attached errors; scanning related: mesh hole errors, stitching errors, reliability errors, umbrella effect errors, distance errors, and distortion errors (scanning strategy). Clinical screenshots were collected for each error type and correlated with scanning conditions, patient-related factors, and operator experience level. All error categories were observed in clinical practice. Mesh holes and distance discrepancies were the most common, particularly in full-arch scans and around ISBs. Reliability errors were specific to scanners offering real-time scan confidence indicators. Umbrella and ISB-related errors frequently stemmed from insufficient cutting or poor rescanning techniques. Humidity scanning errors occur when moisture is present on the scanned surface, so drying the area and using a colorless visualization mode can help improve scan accuracy. Visual documentation of each error type has been compiled for educational and calibration purposes. Systematically identifying and classifying operator-related scanning errors in daily practice enables a deeper understanding of the human factors affecting IOS accuracy. These findings highlight the importance of structured error awareness and targeted operator training to enhance scan reliability in restorative and implant workflows.