Three-dimensional comparison of 2 digital models obtained from cone-beam computed tomographic scans of polyvinyl siloxane impressions and plaster models

Abstract

Purpose: This study was performed to evaluate the dimensional accuracy of digital dental models constructed from conebeam computed tomographic (CBCT) scans of polyvinyl siloxane (PVS) impressions and cast scan models. Materials and Methods: A pair of PVS impressions was obtained from 20 subjects and scanned using CBCT (resolution, 0.1 mm). A cast scan model was constructed by scanning the gypsum model using a model scanner. After reconstruction of the digital models, the mesiodistal width of each tooth, intercanine width, and intermolar width were measured, and the Bolton ratios were calculated and compared. The 2 models were superimposed and the difference between the models was measured using 3dimensional analysis. results: The range of mean error between the cast scan model and the CBCT scan model was -0.15 mm to 0.13 mm in the mesiodistal width of the teeth and 0.03 mm to 0.42 mm in the width analysis. The differences in the Bolton ratios between the cast scan models and CBCT scan models were 0.87 (anterior ratio) and 0.72 (overall ratio), with no significant difference (P>0.05). The mean maxillary and mandibular difference when the cast scan model and the CBCT scan model were superimposed was 53 μm. conclusion: There was no statistically significant difference in most of the measurements. The maximum tooth size difference was 0.15 mm, and the average difference in model overlap was 53 μm. Digital models produced by scanning impressions at a high resolution using CBCT can be used in clinical practice. (Imaging Sci Dent 2019; 49: 257-63)

Validity and reliability of digital models generated from CBCT scanning

“…To the best of our knowledge, the current research was one of the few studies to be conducted in vivo to compare between these two techniques of virtual models fabrication (12,15,16). Generally, in a systematic review (17,18) it was proved that the mean differences between linear measures on stone and virtual models are within this range (0.04-0.4 mm) and considered it accepted clinically.…”

“…Thereby, digital model production using CBCT scans of patient impressions and casts is an alternative method to intraoral scanner or a desktop scanner without the need for directly irradiating the patient. Moreover, single impression can be used for both virtual and stone models fabrication if needed (12,13). Of particular interest is the reliability and accuracy of some of these newer techniques and their applications in-vivo in relation to well established methods, such as conventional stone casts as the previous studies were conducted mainly in-vitro.…”

Comparative Evaluation of Digitization of Diagnostic Dental Cast (Plaster) Models Using Different Scanning Technologies

“…Our results concerning the analysis of CBCT scans are also in line with those reported in the literature, not as much for scanning models but for scanning dental impressions [ 1 ]. Park et al reported the accuracy of CBCT in scanning impressions and compared it to measurements made on plaster dental models [ 27 ]. The average difference in this study was 0.15 mm, which was also considered clinically acceptable; this result coincides with the result of our study—a median difference of 0.14 mm.…”

Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners: An In Vitro Study

“…Intraoral scanners (IOS) are used in dentistry as a convenient method of taking impressions [ 1 , 2 , 3 , 4 , 5 , 6 ]. Orthodontic tooth movement can also be easily evaluated using IOS [ 7 , 8 ].…”