Analysis on the accuracy of intraoral scanners: The effects of mandibular anterior interdental space

In this study, we evaluated the effects of mandibular anterior interdental space on the accuracy of intraoral scanners. Four models of mandibular arch with varying distances of anterior interdental space were analyzed; incisors were evenly spaced out between the two canines by 0 mm, 1 mm, 3 mm, and 5 mm. The full arch of each model was scanned 10 times with iTero® and Trios®. The images were superimposed with those from the reference scanner (Sensable S3) and compared using Geomagic Verify. Statistical analysis was conducted using a t-test, paired t-test, and one-way analysis of variance (ANOVA). Differences in the accuracy of images were statistically significant according to both iTero® and Trios®; a greater deviation was noted with increasing anterior interdental space (p < 0.05). Upon dividing the lower arch into five sections, larger deviation was observed with iTero® in the molar area, except in the model with 1 mm space. With Trios®, the largest deviation was observed in the right molar area in all models. The maximum deviations of intermolar width were 0.66 mm and 0.76 mm in iTero® and Trios®, respectively. This comparison suggests that Trios® demonstrates a higher accuracy than iTero® in all models and in all sections of the arch. However, the mean deviations indicate that both iTero® and Trios® are clinically acceptable.