Related Experiment Video
Updated: May 13, 2025
Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Impact of operator experience, scanning pattern, and arch location on the time and trueness of complete denture
Kedith Sawangsri1, Satita Leelaluk2, Passent Ellakany3
1Clinical Assistant Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio.
Statement Of Problem:
The use of intraoral scanners (IOSs) to digitize complete dentures has been widely adopted. However, the impact of operator experience, scanning patterns, and arch location on the accuracy and scanning time of complete dentures digitized with an IOS is unclear.
Purpose:
The purpose of this in vitro study was to investigate the impact of user experience, scanning patterns, and arch location on the trueness and scanning time of complete dentures digitized with an IOS.
Material And Methods:
One maxillary and 1 mandibular complete denture were fabricated and scanned using a desktop scanner (E4) to be used as the reference scans. Three experienced (Exp) and 3 inexperienced (Inexp) operators performed denture digitization using an IOS (TRIOS 4) with 2 different scanning patterns: the manufacturer's recommended (MA) and the rolling (RO) scan strategy (n=10). The scanning time for each scan was recorded. Using a 3-dimensional (3D) inspection software program (Geomagic Control X), corresponding test scans were compared with the reference scan using overall best-fit alignment to analyze the trueness (root mean square, RMS). Three-way ANOVA followed by the Bonferroni post hoc tests were applied to analyze the effect of user experience, scanning patterns, and arch location on the trueness and scanning time (α=.05). Qualitative analysis of trueness was performed by using 3D color mapping.
Results:
For the trueness of maxillary denture digitization, the Inexp MA group demonstrated the highest RMS value (0.144 ±0.060 mm), while the Exp MA showed the lowest RMS value (0.118 ±0.019 mm). The trueness of mandibular denture digital duplicates exhibited comparable RMS values, ranging from 0.096 ±0.016 mm to 0.101 ±0.017 mm. Analysis of variance revealed significant effects of both arch location and operator experience on the trueness of denture digitization using an intraoral scanner (IOS) (P<.001 and P=.001, respectively). Maxillary digital duplicates exhibited significantly higher RMS values than their mandibular counterparts. Additionally, maxillary duplicates obtained by experienced operators had lower RMS values than those obtained by inexperienced operators. Operator experience also significantly influenced scanning time (P<.01), with experienced operators requiring less time than inexperienced operators, regardless of scanning pattern. Qualitative analysis using 3D color mapping identified increased discrepancies in the maxillary palatal area in scans acquired by inexperienced operators.
Conclusions:
Operator experience and arch location significantly impacted the trueness of maxillary denture digitization, while only operator experience significantly influenced the scanning time of maxillary and mandibular denture digitization using an IOS.
