Accuracy of full arch scans using the iTero Element 2® intra-oral scanner: A clinical study

Abstract

Objective: To investigate the accuracy of full arch scans taken using the iTero Element 2® under clinical settings. Design: Prospective clinical study. Methods: A customised upper removable appliance (URA) with four spheres (A–D) was fabricated from a maxillary arch iTero® scan for a 24-year-old patient. Six linear values were measured on the URA using a high-accuracy coordinate measuring machine. A total of 60 intra-oral iTero® scans were taken by two operators (HA and AS) with the test URA inserted to the participant’s maxillary dentition at T1 and T2. Geomagic Control X software was used to measure the six linear distances between the reference spheres (1–4) in all scans. Comparisons between distances on full arch scans to true distances on the URA were made to evaluate accuracy. Results: The median distance to the prepared bench top URA mean was significantly away from zero for each operator and timepoint across all measurements except AD versus 14 and BD versus 24. Statistically significant, although clinically non-significant, differences in median linear distances in relation to the prepared benchtop URA were observed between evaluators in segments AB versus 12 (operator 1 −0.021 mm vs. operator 2 −0.06 mm) and AC vs. 13 (operator 1 −0.044 mm vs. operator 2 −0.167 mm) at T1. Conclusion: The accuracy of scanners is defined as the trueness and precision of the captured scans to the dental arches. The accuracy of iTero Element 2® is acceptable for diagnosis and treatment planning in orthodontics. Length and location of the scanned segment and scanning sequence ‘protocol’ affect accuracy.