Abstract
ObjectiveIn-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.MethodsTrial 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.ResultsThe 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.ConclusionDimensional 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.
Highlights
Alginate is one of the most frequently used dental materials [1]
2.1.Trial design The present study was a prospective non-randomized comparative clinical trial conducted at the University Clinic of Muenster, Germany
All patients were in active treatment and a removable appliance was planned according to their treatment plan
Summary
Alginate is one of the most frequently used dental materials [1]. The low cost, the good tolerability by younger patients, the ease of handling, the short setting time, the simple technique and the sufficient precision [2] makes alginate the gold standard for orthodontic diagnostics and manufacturing removable appliances.With the ongoing development of digital procedures, intraoral scanning devices and associated workflows are conquering the dental practice. The low cost, the good tolerability by younger patients, the ease of handling, the short setting time, the simple technique and the sufficient precision [2] makes alginate the gold standard for orthodontic diagnostics and manufacturing removable appliances. The intraoral scan and its digital models are being considered as a replacement for conventional impressions in orthodontics because of several potential advantages in hygienic handling, comfort of treatment, transferring of data, analysing and storaging diagnostic models and manufacturing orthodontic appliances. Both techniques, the conventional alginate impression and the intraoral scan, have different advantages and disadvantages, so that. With regard to the manufacture of removeable appliances, the scanning process must be robust against several intraoral conditions (Fig. 1), e.g. salivacovered surfaces (reflectivity), moving soft tissues, varying object to sensor distances in regions with clefts, missing teeth or eruption problems, different dental materials with different reflectivity (fillings, temporary crowns, brackets) and dimensions (wires, temporary anchorage devices)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
