Accuracy of intraoral scans in the mixed dentition: a prospective non-randomized comparative clinical trial

Abstract

Objective: In-vivo accuracy of intraoral scans of complete mixed dentitions of patients in active treatment have not yet been investigated. The aim was to test the hypothesis that dimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant. Methods: Trial design: Prospective non-randomized comparative clinical trial. Based on sample size calculation 44 evaluable mixed dentition jaws of patients in active orthodontic treatment were included. Each patient received an alginate impression following an intraoral scan (TRIOS® Ortho). Plaster cast was fabricated and scanned with an external scanner (ATOS-SO®). Both STL datasets were analyzed with the 3D inspection and mesh processing software GOM Inspect®. Statistical analysis comprised sample size calculation, t-test as well as nonparametric tests. Results: The absolute mean difference between digital plaster casts and intraoral scans is 0.022 mm ± 0.027 mm (median 0.015 mm). The obtained measurements are in the range of comparable studies on full arch permanent dentitions. Gender, the size of the jaw represented by the dentition stage and upper respectively lower jaw, as well the malocclusion have no effect on the total deviations between digital plaster casts and intraoral scans. Detectable impression errors were bubbles in fissures and marginal ridges as well as incomplete alginate flow and detachment from the tray. Detectable scanning errors were incomplete distal surface of the most distal molar. Conclusion: Dimensional differences between intraoral scans and conventional alginate impressions in the mixed dentition are clinically irrelevant for orthodontic purposes. In all clinical situations of active treatment in the mixed dentition, the intraoral scans are more detailed and less error-prone.

Comparison of Accuracy of Alginate Impression and Intraoral Scanner in Model with and without Orthodontic Brackets

“…Nowadays, the relative degree of accuracy between alginate impressions and the IOS method remains controversial. Liczmanski et al [16] reported that intraoral scans were more detailed and less error-prone compared to alginate impressions. On the other hand, Ender et al [10] reported that the accuracy of IOS and alginate impressions in a full arch model without orthodontic brackets were not different.…”

The University Münster model surgery system for orthognathic surgery - The digital update

“…2 Orthodontist, Department Orthodontics, University of Münster, Albert-Schweitzer-Campus 1, Gebäude W 30, D-48149 Münster, Germany. 3 Head of Department, Department of Cranio-Maxillofacial Surgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Gebäude W 30, D-48149 Münster, Germany.…”

“…Intraoral scanners are of particular importance in surgery planning. Due to their high accuracy and practicability, they could replace impressions [3], as well as scattered dental morphology in cone-beam computed tomographs [4]. They are therefore applicable to create composite virtual skull models and conventional planning procedures.…”

Analysis of the relationship between the surface topography of prepared tooth surfaces and data quality of digital impressions from an intraoral scanner

“…Therefore, fewer triangular units result in a further generalized and vague representation of the surface. 14 , 15 , 16 A few 3-D inspection and mesh-processing software programs, 17 , 18 , 19 , 20 which offer tools and features for analyzing and optimizing digitized data before manufacturing, can be used to investigate the surface topography of digitized scans by displaying and measuring these triangular units and triangulation points.…”