• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.104-115
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• 2018

Purpose: The purpose of this study is to evaluate the image acquisition ability of intraoral scanners by analyzing the comprehensiveness of scanned images from standardized model, and to identify problems of the model. Materials and Methods: Cast models and 3D-printed models were prepared according to international standards set by ISO12836 and ANSI/ADA no. 132, which were then scanned by model scanner and two different intraoral scanners (TRIOS3 and CS3500). The image acquisition performance of the scanners was classified into three grades, and the study was repeated with varying surface conditions of the models. Results: Model scanner produced the most accurate images in all models. Meanwhile, CS3500 showed good image reproducibility for angled structures and TRIOS3 showed good image reproducibility for rounded structures. As for model ingredients, improved plaster model best reproduced scan images regardless of the type of scanner used. When limited to 3D-printed model, powdered surface condition resulted in higher image quality. Conclusion: When scanning structures beyond FOV (field of view) in standardized models (following ISO12836 and ANSI/ADA 132), lack of reference points to help distinguish different faces confuses the scanning and matching process, resulting in inaccurate display of images. These results imply the need to develop a new standard model not confined to simple pattern repetition and symmetric structure.

• The Journal of Advanced Prosthodontics
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• v.13 no.5
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• pp.316-326
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• 2021

PURPOSE. Purpose of this in vitro study was to determine the accuracy of different intraoral scans versus laboratory scans of impressions and casts for the digitization of an edentulous maxilla. MATERIALS AND METHODS. A PEEK model of an edentulous maxilla, featuring four hemispheres on the alveolar ridges in region 13, 17, 23 and 27, was industrially digitized to obtain a reference dataset (REF). Intraoral scans using Cerec Primescan AC (PRI) and Cerec AC Omnicam (OMN), as well as conventional impressions (scannable polyvinyl siloxane) were carried out (n = 25). Conventional impressions (E5I) and referring plaster casts were scanned with the inEOS X5 (E5M). All datasets were exported in STL and analyzed (Geomagic Qualify). Linear and angular differences were evaluated by virtually constructed measurement points in the centers of the hemispheres (P13, P17, P23, P27) and lines between the points (P17-P13, P17-P23, P17-P27). Kolmogorov-Smirnov test and Shapiro-Wilk test were performed to test for normal distribution, Kruskal-Wallis-H test, and Mann-Whitney-U test to detect significant differences in trueness, followed by 2-sample Kolmogorov-Smirnov test to detect significant differences in precision (P < .008). RESULTS. Group PRI showed the highest trueness in linear and angular parameters (P < .001), while group E5I showed the highest precision (P < .001). CONCLUSION. Intraoral scan data obtained using Primescan showed the highest trueness while the indirect digitization of impressions showed the highest precision. To enhance the workflow, indirect digitization of the impression itself appears to be a reasonable technique, as it combines fast access to the digital workflow with the possibility of functional impression of mucosal areas.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.1
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• pp.55-59
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• 2017

Digital dentistry has influenced many dental procedures, such as three-dimensional (3D) diagnosis and treatment planning, surgical splints, and prosthetic treatments. Patient-specific protective appliances (PSPAs) prevent dental injury during endotracheal intubation. However, the required laboratory work takes time, and there is the possibility of tooth extraction while obtaining the dental impression. In this technical report, we utilized new digital technology for creating PSPAs, using direct intraoral scanners and 3D printers for dental cast fabrication.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.17-31
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• 2018

Purpose: The purpose of this study was to investigate the accuracy of the interocclusal relationship between upper and lower teeth according to the buccal interocclusal record scan using various intraoral scanner systems. Materials and Methods: The upper and lower full arch Models with normal occlusion were scanned with 5 intraoral scanners (Cerec Omnicam, CS3500, iTero, Trios, True Definition). Buccal interocclusal record scan was taken only at the left side while occlusion was intentionally raised by 1 mm, 2 mm, 3 mm, and 4 mm with metal cylinder core embedded within polyvinylsiloxane bite registration material at the right molar region. The superimposition analysis was done to evaluate overall three-dimensional deviation and cross-section analysis was done to evaluate the degree and the direction of deviation of interocclusal relationship. Results: From the superimposition study, Cerec Omnicam showed the least deviation ($165.5{\mu}m$) and CS3500 ($369.0{\mu}m$) showed the largest (P < 0.01). And the deviation was greater in 3, 4, 2 mm group than 1 mm (P < 0.01). From the cross-section study, Cerec Omnicam showed the farthest deviation ($-242.8{\mu}m$) and CS3500 showed the closest deviation ($312.5{\mu}m$) and a significantly high value was shown in 3 mm group. Conclusion: Every intraoral scanner has different accuracy in reproducing interocclusal relationship.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.299-306
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• 2020

PURPOSE. The aim of this study was to evaluate the accuracy of six recently introduced intraoral scanners (IOSs) for single crown preparations isolated from the complete arch, and to determine the effect of scanning sequence on accuracy. MATERIALS AND METHODS. A complete arch with right and left canine preparations for single crowns was used as a study model. The reference dataset was obtained by scanning the complete arch using a highly accurate industrial scanner (ATOS Core 80, GOM GmbH). Six different IOSs (Trios, iTero, Planmeca Emerald, Cerec Omnicam, Primescan, and Virtuo Vivo) were used to scan the model ten times each. The scans performed with each IOS were divided into two groups, based on whether the scanning sequence started from the right or left quadrant (n=5). The accuracy of digital impression was evaluated using three-dimensional analyzing software (Geomagic Studio 12, 3D Systems). The Kruskal Wallis and Mann- Whitney U statistical tests for trueness analysis and the One-way ANOVA test for precision analysis were performed (α=.05). RESULTS. The trueness and precision values were the lowest with the Primescan (25 and 10 ㎛), followed by Trios (40.5 and 11 ㎛), Omnicam (41.5 ㎛ and 18 ㎛), Virtuo Vivo (52 and 37 ㎛), iTero (70 and 12 ㎛) and Emerald (73.5 and 60 ㎛). Regarding trueness, iTero showed more deviation when scanning started from the right (P=.009). CONCLUSION. The accuracy of digital impressions varied depending on the IOS and scanning sequence used. Primescan had the highest accuracy, while Emerald showed the most deviation in accuracy for single crown preparations.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.67-76
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• 2020

With the evolution of the computer-aided design/computer-aided manufacturing (CAD/CAM) technology, the intraoral scanners are playing an increasingly important role, as they are the first step towards a completely digital workflow. The CAD/CAM double scanning technique has been used to transfer the information from provisional restorations to definitive restorations. In this case, a 67-year-old male with esthetically compromised anterior teeth, generalized severe attrition of teeth, and reduced vertical dimension was treated with full mouth rehabilitation including a re-establishment of the lost vertical dimension of occlusion assisted by the crown lengthening procedure. The provisional restorations were fabricated using an intraoral scanner and the CAD/CAM double scanning technique. After the period of adaption, the definitive monolithic zirconia restorations were delivered. The CAD/CAM double scanning technique successfully transferred the occlusal and morphological characteristics, obtained from the provisional restorations, to the definitive restorations.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.253-258
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• 2016

The development of translucent zirconia enabled clinicians to choose a monolithic zirconia crown as one treatment modality in the posterior dentition. Careful occlusal adjustments are recommended for monolithic zirconia crowns because grinding zirconia inevitably causes phase transformation, which may deteriorate mechanical properties. intraoral scanners enable the clinician to scan and superimpose a complete tooth structure before preparation onto the prepared abutment. This technique helps to reproduce the original tooth form and occlusion of the patient. In this case report, prostheses were fabricated for patients with cracked or fractured tooth by applying intraoral scanner, Computer aided design-computer aided manufacturing (CAD-CAM) and monolithic zirconia crown to reproduce the occlusion of original tooth and to minimize occlusal adjustment. The clinical results were satisfactory in both esthetic and functional aspects.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.1
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• pp.55-65
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• 2024

This study aimed to assess the accuracy of tooth widths, intermolar widths, and arch lengths acquired through two intraoral scanners, including iTero Element Plus Series (Align Technology, Santa Clara, CA, USA) and Trios 4 (3Shape, Copenhagen, Denmark), specifically on mixed dentition. A total of 30 subjects were divided into 2 groups, each undergoing both alginate impressions and intraoral scanning using either the iTero or Trios scanner. The plaster models were measured with a caliper, while the digital models were measured virtually. In the iTero group, all tooth width measurements exhibited differences compared to the plaster values, except for maxillary left lateral incisors (p = 0.179), mandibular right (p = 0.285), and left (p = 0.073) central incisors. The Trios group did not display significant differences in any of the tooth width measurements. Intermolar width comparisons for both groups indicated differences, except for mandibular primary canine to primary canine values (p = 0.426) in the iTero group. Regarding arch length, the mandibular anterior, maxillary right, and left arch lengths in the iTero group demonstrated larger caliper values than those of iTero. Conversely, in the Trios group, all parameters showed smaller caliper values, especially in upper anterior, maxillary right, mandibular right, and mandibular left arch lengths with significance (p = 0.027, 0.007, 0.003, and 0.047, respectively). Despite the differences between the two groups, digital models might be clinically suitable alternatives for plaster models. Pediatric dentists should carefully assess these differences, as a comprehensive evaluation would result in precise orthodontic treatment planning and favorable outcomes for young patients with mixed dentition.

• The Journal of Advanced Prosthodontics
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• v.15 no.6
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• pp.290-301
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• 2023

PURPOSE. The study aimed to determine the influence of implant angulation on the trueness of multi-unit implant impressions taken through different techniques and strategies. MATERIALS AND METHODS. As reference models, three partially edentulous mandibular models (Model 1: No angulation; Model 2: No angulation for #33, 15-degree distal angulation for #35 and #37; Model 3: No angulation for #33, 25-degree distal angulation for #35 and #37) were created by modifying the angulations of implant analogues. Using a lab scanner, these reference models were scanned. The obtained data were preserved and utilized as virtual references. Three intraoral scanning (IOS) strategies: IOS-Omnicam, ISO-Quadrant, and IOS-Consecutive, as well as two traaditional techniques: splinted open tray (OT) and closed tray (CT), were used to create impressions from each reference model. The best-fit alignment approach was used to sequentially superimpose the reference and test scan data. Computations and statistical analysis of angular (AD), linear (LD), and 3D deviations (RMS) were performed. RESULTS. Model type, impression technique, as well as interaction factor, all demonstrated a significant influence on AD and LD values for all implant locations (P < .05). The Model 1 and SOT techniques displayed the lowest mean AD and LD values across all implant locations. When considering interaction factors, CT-Model 3 and SOT-Model 1 exhibited the highest and lowest mean AD and LD values, respectively. Model type, impression technique, and interaction factor all revealed significant effects on RMS values (P ≤ .001). CT-Model 3 and SOT-Model 1 presented the highest and lowest mean RMS values, respectively. CONCLUSION. Splinted-OT and IOS-Omnicam are recommended for multi-unit implant impressions to enhance trueness, potentially benefiting subsequent manufacturing stages.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.43-54
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• 2021

Based on rapid improvement in digital fields, many advanced digital technologies are utilized in prosthodontic treatment. Especially, intraoral scanners and 3D printing technology are commonly used, and facial scanning technology is recently being attempted to be part of these digital routines. This case report aims to introduce a digital procedure using the intraoral scanner, facial scanner, and 3D printing technology to create definitive restorations, which are esthetic and harmonious with patient's face. From thoroughly evaluated full-mouth provisional restoration which was manufactured and fitted conventionally, definitive prostheses were fabricated using various digital technique. Stable occlusion with functionally and aesthetically satisfying results were achieved.