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Updated: Jul 17, 2026
Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
Effect of adherence to scanning protocol on the accuracy of digital interocclusal records
Omer Einhorn1, Yaniv Skvirsky1, Dror Aizenbud2
1Senior Resident, Department of Prosthodontics, School of Graduate Dentistry, Rambam Health Care Campus, Haifa, Israel.
Statement Of Problem:
The accuracy of virtual interocclusal records is critical in fully digital prosthodontic workflows. Although manufacturers provide recommended scanning protocols, clinicians may deviate from them in daily practice. The impact of such deviations on virtual articulation accuracy across intraoral scanners remains unclear.
Purpose:
The purpose of this in vitro study was to evaluate and compare the accuracy of virtual interocclusal records obtained using 4 intraoral scanners under manufacturer-recommended and alternative scanning protocols.
Material And Methods:
A typodont cast was duplicated in Type III dental stone, mounted in maximum intercuspal position (MIP) on a semi-adjustable articulator, and scanned. Four intraoral scanners-TRIOS3 (TS), Primescan (PS), Smile Scan (SM), and CS3800 (CS)-were used to obtain interocclusal records (n=10 per scanner per protocol) using manufacturer-recommended protocols and alternative protocols deviating from manufacturer instructions (complete arch or bilateral interocclusal registration scans). The standard tessellation language (STL) files were analyzed in Geomagic Control X, aligned to a reference cast, and trueness and precision were assessed at 3 standardized locations. Mixed-design ANOVA models were applied to RMS bias (trueness), with position (left, center, right) as a within-subject factor and scanner type as a between-subject factor; protocol was included as an additional between-subject factor, with a separate model for CS3800. Post hoc pairwise comparisons were performed using the Tukey adjustment (α=.05).
Results:
Under manufacturer-recommended protocols, no significant differences in trueness were observed among TS (0.215 mm), PS (0.242 mm), and SM (0.222 mm) (P>.05), with precision ranging from ±0.032 to ±0.050 mm. CS showed significantly higher trueness deviation (0.343 mm; P<.001). With alternative protocols, scanner-dependent differences emerged. PS maintained comparable trueness (0.242 versus 0.245 mm; P>.05). TS showed a significant increase in trueness error (0.215-0.438 mm; P<.001). SM showed statistically similar trueness (0.222 and 0.246 mm; P>.05). CS maintained high trueness deviations (0.391 and 0.386 mm) with precision values of ±0.115 and ±0.081 mm.
Conclusions:
When manufacturer-recommended protocols were followed, favorable trueness values were obtained for all scanners. When alternative scanning protocols were employed, only Primescan remained stable across all sites, whereas the other scanners showed protocol-dependent deviations.
